Aerobic and Anaerobic Biotransformation of Chloroanilines ...
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Aerobic and Anaerobic Biotransformation of Chloroanilines, Chlorobenzenes, and Dichlonitrobenzenes at a Complex Industrial Site in
Brazil and Analysis of Associated Microbial Communities
by
Suzana de Paula Queiroz Kraus
A thesis submitted in conformity with the requirements for the degree of Master of Applied Science
Department of Chemical Engineering and Applied Chemistry University of Toronto
© Copyright by Suzana de Paula Queiroz Kraus 2018
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Aerobic and Anaerobic Biotransformation of Chloroanilines, Chlorobenzenes, and Dichlonitrobenzenes at a Complex Industrial Site in
Brazil and Analysis of Associated Microbial Communities
Suzana de Paula Queiroz Kraus
Master of Applied Science
Department of Chemical Engineering and Applied Chemistry
University of Toronto
2018
Abstract
Environmental contamination is a widespread problem and many industrial sites need
significant attention. The potential for using bioremediation as a low cost environmentally-
friendly restoration approach was evaluated at a contaminated site in Brazil. Aerobic and
anaerobic biotransformation of chloroanilines, chlorobenzenes, and dichloronitrobenzenes were
studied in long-term microcosm experiment, where novel reactions were observed, such as
anaerobic biotransformation of dichloronitrobenzenes. Further microbial community analysis
was performed based on multiple samples with the objective to recommend a course of action at
the site. To evaluate the identity and distribution of microorganisms in microcosms and field
samples, amplicon sequencing of the 16S rRNA gene was performed. Cupriavidus was found to
degrade dichlorobenzenes, Diaphorobacter degrades dichloronitrobenzenes aerobically, among
others. Statistical analysis was done to interpret the data and identify significant factors that
drive a microbial community. The conclusion is that this site has a high potential for being
bioremediated, by promoting aerobic biodegradation processes.
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Acknowledgments
This thesis and work would not have been possible without help and support from really
important people in my academic, professional, and personal life.
Firstly, I would like to thank my supervisor, Dr. Elizabeth Edwards, who has always shown
passion and excitement about research and has inspired me during the past two years! I extend
my thanks to my committee members, Dr. Elodie Passeport and Dr. Gary Wealthall, for their
availability to help and provide guidance in this important step of my academic life.
I would like to thank DuPont for proving the funding for this research. Special thanks to James
K. Henderson, Paloma Carvalho, and Elizabeth Erin Mack for being so supportive during these
years and for teaching me so much. I really appreciate this opportunity!
Thank you Line Lomheim for training me since the beginning of my program, for being so
patient and kind everyday, and for doing such an amazing work with the Camaçari microcosms.
Thank you Camilla Nesbø for helping me with bioinformatics and being patient enough to teach
me a complete new world of command lines and scripts. Thank you to Amy Li for helping in the
laboratory over the summers. You all have contributed a lot to this research!
Thank you to Susie Susilawati for saving me every time I needed to be and for always being
“awesome!”. Thank you Vinthiya Paramananthasivam and Katrina Chu for the administrative
support and for your kindness.
I would like to thank Savia Gavazza for giving me best hugs and smiles ever! I felt like part of
your family while you were in Toronto and I could not be more thankful for this. When I think
about the moments I spent with your lovely daughters, Mari and Lili, I can only think about
love, happiness, and peace.
Thank you to my friends from Ed Lab who were always ready to help with anything I needed. I
learned a lot during these years and all of you were part of it! Thank you for all the fun moments
we had together. I would like to thank Nadia Morson for not only baking every week with me,
but for all the talks, advices, and great moments we spent together – you’re my best miga and it
has been great to have you for these two years! Special thanks to Lais Mazullo and Peter Lee for
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also being so amazing to me! Charlie Chen, Ivy Yang, Fei Luo, Olivia Molenda, Courtney Toth,
Luz Puentes, Shen Guo, Zahra Choolaei, and Mabel Wong, thank you for your support and
friendship.
Speaking of friends, I have to thank my friends from Brazil who are my second family! Even
from far away, I always had their support, we were always close, and this was really important
to help me through tough times here in Toronto. We have known each other for over 20 years
now, so you probably know I’m writing this and crying like a baby. I miss you guys so much!
A special thank you for my boyfriend Jovi for his endless love, support, and patience. Thank
you for being there every time I needed you and for believing in me even more than I did. This
is just the beginning of a beautiful history we are writing together! I love you.
And most importantly my family: my mom Mariangela, my dad Euclydes, and my sister Marina
for being the best human beings I have even known. Thank you for always believing in me, for
being supportive in my decisions, and for your love. I miss you everyday since I got here and
many times I wish to be there with you. This thesis is for you!
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Table of Contents
Acknowledgments .................................................................................................................. iii
Table of Contents ...................................................................................................................... v
List of Tables ...........................................................................................................................ix
List of Figures ........................................................................................................................... x
List of Appendices ................................................................................................................. xii
List of Abbreviations .............................................................................................................. xv
Chapter 1 Literature review and objectives .............................................................................. 1
Literature review ........................................................................................................... 1
1.1.1 Remediation and bioremediation ...................................................................... 1
1.1.2 The presence of pesticides in soil and groundwater ......................................... 1
1.1.3 Site history ........................................................................................................ 2
1.1.4 Compounds of interest (COIs) for this study .................................................... 3
Research objectives ...................................................................................................... 6
Thesis structure ............................................................................................................. 6
Chapter 2 Materials and Methods ............................................................................................. 8
Preparation of Solutions ............................................................................................... 8
2.1.1 COI stock, sodium sulfate, sodium nitrate, and sodium lactate solutions ........ 8
2.1.2 Anaerobic mineral medium .............................................................................. 9
Microcosm study ........................................................................................................ 11
2.2.1 Microcosm study set up .................................................................................. 11
2.2.2 VOC monitoring using GC ............................................................................. 14
2.2.3 SVOC monitoring using HPLC ...................................................................... 14
2.2.4 Other measurements: oxygen, pH, and sulfate and nitrate concentrations ..... 15
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Preparation of samples for DNA extraction ............................................................... 16
2.3.1 Groundwater samples ..................................................................................... 16
2.3.2 Soil samples .................................................................................................... 17
DNA extraction, amplicon sequencing, and qPCR .................................................... 17
Statistical analysis: MetaAmp and RStudio ............................................................... 18
Road map of experiments conducted during this research ......................................... 19
Chapter 3 Background: Microcosm study #1 ......................................................................... 21
Motivation and sample location.................................................................................. 21
Methodology and COIs............................................................................................... 21
Results and discussion ................................................................................................ 23
3.3.1 Aerobic microcosms ....................................................................................... 23
3.3.2 Anaerobic microcosms ................................................................................... 26
Chapter 4 Laboratory activity tests ......................................................................................... 30
Aniline and chloroaniline anaerobic microcosm study #2 ......................................... 30
4.1.1 Motivation and sample collection ................................................................... 30
4.1.2 Methodology ................................................................................................... 30
4.1.3 Results and discussion .................................................................................... 31
Aerobic degradation experiments of multiple COIs in Camaçari laboratory, Brazil . 31
4.2.1 Motivation and sample collection ................................................................... 31
4.2.2 Methodology ................................................................................................... 32
4.2.3 Results and discussion .................................................................................... 33
Highly enriched cultures from collaborating laboratories .......................................... 34
4.3.1 Motivation and samples .................................................................................. 34
4.3.2 Methodology ................................................................................................... 35
4.3.3 Results ............................................................................................................ 36
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Influence of pH in microcosms................................................................................... 38
4.4.1 Motivation and samples .................................................................................. 38
4.4.2 Methodology ................................................................................................... 39
4.4.3 Results ............................................................................................................ 40
Chapter 5 Microbial community analysis ............................................................................... 41
Motivation and samples .............................................................................................. 41
Results and discussion ................................................................................................ 44
5.2.1 qPCR of samples from microcosms, enriched cultures, soil, groundwater, and
groundwater from Cetrel................................................................................. 44
5.2.2 Main operational taxonomic units (OTUs) in groundwater and soil samples
from the site .................................................................................................... 46
5.2.3 Changes in microbial community over time in microcosms samples ............ 51
5.2.4 Comparison between external cultures, microcosms samples, and
environmental samples ................................................................................... 59
5.2.5 NMDS analyses in multiple groups of samples .............................................. 62
Chapter 6 Conclusions and future work ................................................................................. 72
Conclusions ................................................................................................................ 72
6.1.1 Aerobic and anaerobic reactions observed during microcosms study ............ 72
6.1.2 Impact of pH in different degradation laboratory tests ................................... 72
6.1.3 Microbial community analysis ....................................................................... 73
6.1.4 Potential microorganisms responsible for biodegrading COIs in this study .. 73
Recommendations and future work ............................................................................ 75
References............................................................................................................................... 77
Appendix A. Supplementary information for Chapter 1 ........................................................ 83
Appendix B. Supplementary information for Chapter 2 ........................................................ 94
Appendix C. Supplementary Information for Chapter 3 ........................................................ 98
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Appendix D. Supplementary information for Chapter 4 ...................................................... 106
Appendix E. Supplementary information for Chapter 5 ....................................................... 123
Appendix F. Supplementary information for statistical analyses ......................................... 145
Appendix G. Electronic files available as supplementary data ............................................ 161
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List of Tables
Table 2.1 Treatment table for microcosms study #1……………………………………………13
Table 3.1 Summary of aerobic biodegradation observed during main microcosm study............24
Table 3.2 Summary of anaerobic reactions observed during main microcosm study…………..26
Table 6.1 Summary of aerobic degradation and anaerobic biotransformation observed in the
microcosm study #1….………………………………………………………………………….72
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List of Figures
Figure 2.1 Microcosm study set up……………………………………………………………...12
Figure 2.2 Groundwater filtration set up………………………………………………………..17
Figure 2.3 Road map for experiments in this research………………………………………….20
Figure 3.1 Sample location for microcosm study #1………………………………………...….22
Figure 3.2 Concentration versus time in an aerobic active control microcosm from site 1A…..25
Figure 3.3 Concentration of SVOCs versus time in anaerobic electron donor amended
microcosm from site 2A ………………………………………………………………………..29
Figure 4.1 Impact of pH and bioaugmentation on aerobic microcosms from site 2A…………..37
Figure 4.2 Impact of pH and bioaugmentation on aerobic microcosms from site 1B…………..38
Figure 5.1 qPCR results (copies/mL) for microcosms, soil, groundwater, and pure culture
samples………………………………………………………………………………………….45
Figure 5.2 Relative abundance (> 0.5%) in soil samples collected from the site……………….47
Figure 5.3 Dendrogram and relative abundance (> 1%) in groundwater samples collected from
the site…………………………………………………………………………………………...48
Figure 5.4 Relative abundance (> 0.5%) in groundwater samples from Cetrel and from hydraulic
barrier……………………………………………………………………………….…………...50
Figure 5.5 Relative abundance (%) in aerobic microcosms samples from Site 1A and Site 1B..52
Figure 5.6 Relative abundance (%) in aerobic microcosms samples from Site 2A and Site 2B..53
Figure 5.7 Relative abundance (%) of microorganisms in anaerobic microcosms samples from
site 1A…………………………………………………………………………………………...56
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Figure 5.8 Relative abundance (%) of microorganisms in anaerobic microcosms samples from
site 1B…………………………………………………………………………………………...57
Figure 5.9 Relative abundance (%) of microorganisms in anaerobic microcosms samples from
site 2A………………………………………………………………………………………...…58
Figure 5.10 Most abundant OTUs in external laboratory highly enrichment cultures used for the
experiments in UofT…………………………………………………………………………...…………59
Figure 5.11 Relative abundance (%) of Pandoraea (OTU10) in all the samples……………….61
Figure 5.12 NMDS plots for all the samples……………………………………………………………..64
Figure 5.13 NMDS plots for all microcosms, aerobic microcosms, and anaerobic microcosms………...65
Figure 5.14 NMDS plots for aerobic microcosms and significant OTUs………………………………..66
Figure 5.15 NMDS plots for anaerobic microcosms and significant OTUs…………………………….67
Figure 5.16 NMDS plots for aerobic and anaerobic microcosms from Site 1A and significant
OTUs…………………………………………………………………………………………….68
Figure 5.17 NMDS plots for aerobic and anaerobic microcosms from Site 1B and significant
OTUs…………………………………………………………………………………………….69
Figure 5.18 NMDS plots for aerobic and anaerobic microcosms from Site 2A and significant
OTUs…………………………………………………………………………………………….70
Figure 5.19 NMDS plots for aerobic and anaerobic microcosms from Site 2B and significant
OTUs…………………………………………………………………………………………….71
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List of Appendices
Appendix A Supplementary information for Chapter 1
Table A.1 Concentrations (mg/kg) of specific COIs in soil samples from the site.. ................... 83
Table A.2 Concentrations (mg/L) of specific COIs in groundwater samples from the site. ....... 84
Table A.3 Physical characteristics of COIs.. ............................................................................... 85
Table A.4 Aerobic degradation of aniline and chloroanilines reported in the literature. ............ 86
Table A.5 Anaerobic transformation of aniline and chloroanilines reported in the literature ..... 90
Table A.6 Aerobic degradation of chlorobenzenes reported in the literature. ............................. 91
Table A.7 Anaerobic transformation of chlorobenzenes reported in the literature ..................... 92
Table A.8 Aerobic degradation of dichloronitrobenzenes reported in the literature ................... 93
Appendix B Supplementary information for Chapter 2
Table B.1 Chemical compounds and solvents used……………………………………………..91
Figure B.1 Calibration curve for methane, benzene, and DCBs in GC…………………………92
Figure B.2 Calibration curves for anilines, chloroanilines, dichloroanilines, and
dichloronitrobenzenes in HPLC………………………………………………………………...93
Appendix C Supplementary information for Chapter 3
Figure C.1 Soil samples used for microcosms study #1…….…………………………………..95
Table C.1 Average aerobic degradation rates (mg/L/day) per site in the microcosms………….96
Figure C.1 Concentration versus time in an aerobic active control microcosm from site 2B…..97
Table C.2 Average anaerobic transformation rates (mg/L/day) per site in the microcosms……98
Figure C.3 Anaerobic nitrate amended microcosm……………………………………………..99
Figure C.4 Concentration of SVOCs versus time in anaerobic electron donor amended
microcosm from site 1A……………………………………………………………………….100
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Figure C.5 Concentration of VOCs versus time in anaerobic electron donor amended microcosm
from site 1A……………………………………………………………………………………101
Figure C.6 Concentration of VOCs versus time in anaerobic electron donor amended microcosm
from site 2A……………………………………………………………………………………102
Appendix D Supplementary information for Chapter 4
Figure D.1 Sample location for anaerobic microcosms study #2, assessing aniline and
chloroanilines degradation………………………………………………………..……..….….103
Table D.1 Treatment table for anaerobic microcosms study #2………………………….……105
Figure D.2 Anaerobic transformation graphs for microcosms study, assessing aniline and
chloroanilines……………………………………………………………………………….….106
Table D.2 Treatment table for aerobic test performed in Camaçari laboratory with puddle
water…………………………………………………………………………………………...108
Figure D.3 Aerobic degradation from test conducted in Camaçari with puddle water………..109
Figure D.4 Process of growing aerobic cultures in the laboratory…………………………….113
Table D.1 Experiment set up to test if aerobic microcosms from sites 2A and 1B inoculated with
culture mix would show more degradation……..……………………………………………..115
Table D.4 Influence of pH in microcosms and treatments in the bottles……………………....116
Figure D.5 Results of pH adjustment in aerobic vitamin amended microcosms from site 1A..117
Figure D.6 Results of pH adjustment in aerobic vitamin amended microcosms from site 2A..118
Figure D.7 Results of pH adjustment in aerobic active control microcosms from site 2B……119
Appendix E Supplementary information for Chapter 5
Table E.1 Summary of samples used for microbial community analysis……………………...120
Figure E.1 Groundwater sample location at the site…………………………………………...126
Table E.2 Details of the standard curves generated for qPCR…………………………………127
Table E.3 Raw qPCR results…………………………………………………………………..128
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Figure E.2 qPCR results (copies/mL) for microcosms, soil, groundwater, and pure culture
samples.………….…………………………………………………………………………….133
Figure E.3 Relative abundance (%) of microorganisms in anaerobic microcosms samples from
site 2B………….……………………………………………………………..………………..134
Table E.1 Most abundant OTUs found in pure and enrichment cultures from external
laboratories and tested in UofT………………………………………………………………...135
Figure E.4 Relative abundance (%) of Rhodanobacter (OTU72) in all the
samples……………………………………………………………………………………..….136
Figure E.5 Relative abundance (%) of Pelosinus (OTU43), Desulfotomaculum (OTU89), and
Propionicicella (OTU108) in all the samples……………………………………...…………..137
Figure E.6 Relative abundance (%) of Diaphorobacter (OTU9) in all the samples……..……138
Figure E.7 Relative abundance (%) of Rhodococcus (OTU23) in all the samples………….....139
Figure E.8 Relative abundance (%) of Alcaligenaceae (OTU11) in all the samples………….140
Figure E.9 Relative abundance (%) of Cupriavidus (OTU24) in all the samples…………..…141
Appendix F Supplementary information for statistical analyses
R Markdown script used to analyze all the samples………………..………………………….142
Appendix G Electronic files available as supplementary data
List of files available in Syntrophy folder……………………………………………………..158
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List of Abbreviations
CA Chloroaniline
CB Chlorobenzene
COI Compounds of interest
DCA Chloroaniline
DCB Dichlorobenzene
DCNB Dichloronitrobenzene
DNA Deoxyribonucleic acid
GC Gas chromatography
HPLC High pressure liquid chromatography
IC Ion chromatography
MCB Monochlorobenzene
NMDS Non-metric multidimensional scaling
OTU Operational taxonomic unit
qPCR Quantitative polymerase chain reaction
SVOC Semi-volatile organic compounds
VOC Volatile organic compounds
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Chapter 1 Literature review and objectives
Literature review
1.1.1 Remediation and bioremediation
Industrial activities have exposed soil and groundwater over time to different toxic compounds which are
harmful for humans and ecosystems. Pollutants can enter the environment as a result of spills, leakage
from product storage, and leakage from waste disposal (Khan, et al., 2004). Therefore, remediation is
required to reduce the contamination and risk of exposure, and to restore soil and groundwater functions
(O’Brien, et al., 2017). To achieve a desirable and safe concentration of contaminants in the environment,
different remediation techniques can be applied. Bioremediation is one of these techniques that will be
described further throughout this thesis.
Bioremediation has been studied since the 1940s (Zobell, 1946), but became known and more broadly
studied in the 1980s as an alternative for cleaning up shorelines contaminated with oil spills (Hoff, 1993).
When compared to chemical or physical remediation techniques, bioremediation is a low cost and
environmentally friendly approach that can be widely used, depending on the nature of pollutant and
characteristics of the site (Azubuike, et al., 2016).
It is important to define bioremediation within the context of biodegradation. Biodegradation is a
naturally occurring process in which microorganisms alter and break down contaminant compounds into
other substances or products (Hoff, 1993). Whereas bioremediation is the acceleration of this process,
wherein microorganisms break down the molecules, reducing the abundance of these compounds in the
environment by degradation, detoxification, stabilization, or transformation (Azubuike, et al., 2016). The
process of changing environmental conditions during the biodegradation process, such as temperature or
pH, and providing the microorganisms with better conditions to degrade the contaminants is called
bioremediation.
1.1.2 The presence of pesticides in soil and groundwater
Persistent organic pollutants are of global concern because they are human toxins, harmful for the
environment, and they can be widely transported by air and water. Scientific studies have shown that they
are the most dangerous substances released in the environment by human activities (Gavrilescu, 2005).
These substances can be introduced into the environment by industrial activities, use of fossil fuels, and
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the use of pesticides in the agricultural industry. Moreover, such substances can persist in the
environment after their use, accumulating in soil, sediments, water, and in the atmosphere (Kordel, et al.,
1997).
1.1.3 Site history
The subject of this thesis is a heavily contaminated industrial site in Brazil, located in the Industrial
Complex of Camaçari, in the state of Bahia. This Industrial Complex contains more than 90 chemical and
petrochemical companies and is responsible for an annual revenue of approximately $15 billions USD.
The site used to produce and store raw materials for the production of pesticides and herbicides since
1987 to shut down in 2014.
Between October 2012 and March 2014, an investigation project was conducted on the site to assess the
environmental contamination of soil and groundwater. For 17 months, more than 200 soil and
groundwater samples were collected and analyzed, and a diverse range of contaminants were found in the
shallow and deep layers of this site. The compounds were divided into the following categories: anilines
and chloroanilines, chlorobenzenes, chloronitrobenzenes, BTEX (Benzene, Toluene, Ethylbenzene and
Xylenes), phthalates, pesticides, and others. The focus of this studies were the first three groups of
compounds and the average concentrations found in the site for some of the contaminants are presented in
Table A.1 for soil and Table A.2 for groundwater.
To plan a remediation project for the site, the management team started a series of treatability studies that
aimed to identify different techniques that could be applied to the site, and in the future, reduce the
contamination to acceptable and non-harmful levels, according to local and international standards.
Different universities and consulting firms in Brazil, the U.S., and Canada are involved in this project, but
with different objectives, according to each of their research capabilities.
In 2015, the University of Toronto received soil and groundwater samples from the site to conduct a
microcosm study in which the following compounds of interest (COIs) were analyzed: aniline, 2-
Chloroaniline (2-CA), 3-Chloroaniline (3-CA), 4-Chloroaniline (4-CA), 3,4-Dichloroaniline (3,4-DCA),
2,3-Dichloroaniline (2,3-DCA), 2,5-Dichloroaniline (2,5-DCA), 1,2-Dichlorobenzene (1,2-DCB), 1,3-
Dichlorobenzene (1,3-DCB), 1,4-Dichlorobenzene (1,4-DCB), 2,3-Dichloronitrobenzene (2,3-DCNB),
2,5-Dichloronitrobenzene (2,5-DCNB), and 3,4-Dichloronitrobenzene (3,4-DCNB). More details about
how the study was set up and other tests conducted since 2015 are described later in this thesis. Physical
characteristics of these compounds are shown in Table A.3.
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All of the aforementioned COIs have been studied in the literature independently as single compounds,
but no research has been done about the interactions between them and their inhibitory effects and/or
synergetic effects when combined.
1.1.4 Compounds of interest (COIs) for this study
While many chlorinated organic compounds can be aerobically biodegraded to CO2, the dense non-
aqueous phase liquids compounds (DNAPLs) migrate down to deep zones that are often anaerobic
(Nelson, et al., 2014), and this is the reason why this study was conducted under both conditions. As
previously stated, the COIs are divided in three groups: aniline and chloroanilines, chlorobenzenes, and
chloronitrobenzenes.
Aniline and Chloroanilines
Aromatic amines, such as aniline and chloroanilines (2-, 3-, 4-CA), are raw materials for different
industrial processes and are frequently found in industrial effluents (Orge, et al., 2015). For example, they
are important intermediates in the production of dyes, pharmaceuticals, pesticides, and herbicides
(Latorre, et al., 1984; Zeyer, et al., 1985). These compounds can persist in nature for a long time, and
accumulate in living organisms (Zhu, et al., 2012). Accumulation of dichloroanilines (DCAs) in the
environment can also be caused by the complete reduction of the nitro-group during anoxic
transformation of chlorinated nitroaromatic compounds, such as dichloronitrobenzenes (Tas, et al., 2006).
These aromatic pesticides with amino groups such as diuron, linuron, propanil, and triclocarban can be
transformed into CAs in the environment (Silar, et al., 2011). Besides this, chlorinated nitrobenzenes can
be reduced to the corresponding CA, which can lead the CA accumulation in groundwater, soil, crops,
and sludge (Zhang, et al., 2017).
Other than distribution due to industrial use, 3-CA is one of the primary intermediates generated by
microbial transformation of phenylurea, acylanilide and phenylcarbamate herbicides (Haggblom, 1992;
Zeyer and Kearney, 1982). Another source of accumulation of these compounds in the environment is
from the degradation of other chemicals, such as propanil, a widely used anilide herbicide. Due to its
instability when it is photodegraded, it produces 3,4-DCA, which is more toxic than the herbicide itself
and can persist in the environment for up to 10 years (Bartha, 1971; Herrera-Gonzalez, et al., 2013).
However, under anaerobic conditions, slow degradation to monochloroaniline can occur (Hund-Rinke and
Simon, 2004)
4
As previously stated, bioremediation is the use of microorganisms to degrade specific contaminants in the
environment. A compilation of the literature describing biodegradation of aniline and chloroanilines is
provided in Table A.4 (aerobic) and Table A.5 (anaerobic). This literature review reveals that
Pseudomonas and Delftia are the most common microorganisms related to aerobic degradation of aniline
and chloroanilines. Anaerobically, Desulfobacterium was reported to degrade aniline completely (Schnell and
Schink, 1991), and microorganisms like Desulfobacterium anilini, Ignavibacterium album, and
Dehalococcoides mccartyi were involved in the biotransformation of these compounds.
Chlorobenzenes
Monochlorobenzene (MCB) and dichlorobenzenes (1,2-, 1,3-, 1,4-DCB) have been used industrially as
solvents, surface cleansers, and feedstocks, which has made them common groundwater and soil
contaminants (Fung, et al., 2009). They are also used to produce pesticides and dyes (Chakraborty and
Coates, 2004), and have therefore been extensively released in the environment. These are toxic
compounds and are considered harmful contaminants to human and animal health, as they have been
reported as toxic compounds by the US EPA.
Aerobic chlorobenzene degradation has been studied extensively, and these compounds can be
metabolized aerobically to CO2 by well characterized pathways (Haigler, et al., 1988; Haigler, et al.,
1992; Leahy, et al., 2003). When in contact with nanomolar concentrations of DCBs, Burkholderia sp.
strain PS14 has been shown to degrade highly polychlorinated compounds, such as and 1,2,3-
trichlorobenzene and 1,2,4,5-tetrachlorobenzene (Rapp and Timmis, 1999). Table A.6 shows different
studies conducted under aerobic conditions, showing Pseudomonas as the main microorganism
responsible for the degradation of chlorobenzenes.
But MCB and DCBs can also form dense nonaqueous phase liquid (DNAPLs) which can migrate to deep
and anaerobic regions of the soil, inhibiting aerobic degradation. In these anaerobic environments,
halogenated compounds can serve as an electron acceptor for their degradation by different
microorganisms, such as Dehalococcoides, Desulfobacterium, Dehalobacter, and Sulforospirillum
(Holliger, et al., 1997; Smidt and de Vos, 2004). A microcosm study using sediments from a
contaminated industrial site demonstrated anaerobic degradation of DCBs and MCB, where all the DCBs
isomers were dehalogenated to MCB and then further dehalogenated to benzene (Fung, et al., 2009).
Dehalobacter sp. was involved in the dichlorination of all the isomers, however 1,2-DCB was degraded at
the fastest rate compared to the other isomers (Nelson, et al., 2011). Other studies have also shown that
1,2-DCB was the fastest to be degraded in soil sediments (Elango, et al., 2010; Quistorff, 1999).
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In the literature, previous studies have reported that Dehalococcoides mccartyi CBDB1 can degrade
chlorinated benzenes, but only when the number of chlorine is higher than three, which means MCB and
DCBs cannot be degraded by this organism (Holscher, et al., 2003; Jayachandran, et al., 2003). More
details about anaerobic biotransformation of chlorobenzenes are provided in Table A.7.
Since the research reported in this thesis focuses on the mixture of different mono- or dichlorinated
compounds and analyzes environmental samples with a rich microbial community, it is important to
understand how mixed cultures interact with the COIs as well, instead of just exploring singular
microorganisms in pure cultures.
Chloronitrobenzene
From the chloronitrobenzene group of contaminants, three dichloronitrobenzenes (DCNBs) were
investigated in this study: 2,3-, 2,5-, 3,4-DCNB. Chloronitrobenzenes are toxic and carcinogenic
compounds that have been used in the production of dyes, herbicides, pesticides, and other chemical
substances for the past decades (Zhu, et al., 2015). Although these compounds are intentionally applied to
the environment for agricultural use, the improper handling and poor storage of these compounds might
result in severe soil and groundwater contamination (Ju and Parales, 2010).
Biodegradation of nitrobenzenes has been reported to occur aerobically through an oxidative, meta
cleavage pathway by Comamonas sp. strain JS765, which uses this compound as source or energy
(Nishino and Spain, 1995). Chloronitrobenzene can also be used as source of energy for microbes, such as
Pseudomonas stutzeri ZWLR2-1 that degrades 2-chloronitrobenzene aerobically (Liu, et al., 2005). Xiao
et al. (2006) demonstrated that Pseudomonas putida ZWL73 can transform 4-chloronitrobenzene to 2-
amino-5-chlorophenol.
Palatucci (2017) used soil and groundwater samples from the Camaçari site in Brazil and was able to
identify bacteria responsible for aerobic 2,3- and 3,4-DCNBs degradation. These samples were collected
at the same time as the soil and groundwater samples used for the microcosms study described in Chapter
3. When these DCNBs were degraded, nitrite was released as an end-product of degradation. Isolates
affiliated with Acidovorax, Diaphorobacter and Pseudomonas were found to be responsible for the
observed degradation (Table A.8). Prior to the Palatucci (2017) thesis, aerobic biodegradation of
dichloronitrobenzenes has not been reported in the literature.
Anaerobic biodegradation of 2,5-dichloronitrobenzene was reported in a thesis from Zhang (2016), where
the following carbon sources were used: pyruvate, formate, acetate, and lactate. Results show that bottles
6
amended with pyruvate were able to biotransform 2,5-DCNB after 4 hours of experiment. Some
microorganisms were identified during this work as potential responsible for the biodegradation:
Clostridium sp., Eubacterium sp., Streptomyces sp., and Propionibacterium sp. This work was not fully
available and the information above was taken from the thesis abstracts, available at the website Globe
Thesis, ID number 2271330461978280, available at https://www.globethesis.com/?t=2271330461978280.
To date, this is the only work that has analyzed anaerobic biodegradation of dichloronitrobenzenes.
Research objectives
Aerobic biodegradation and anaerobic biotransformation of aniline, chloroaniline, dichloroaniline,
chlorobenzene, and dichloronitrobenzene has been reported in the literature. However, the mixture of
these compounds has never been studied and this research aims to explore the conditions at which these
compounds degrade and to identify the microbes responsible for degradation at the Camaçari site. To
achieve this goal, laboratory tests, microbial community analyses and statistical analyses were conducted
on groundwater, soil, and enrichment culture samples to address the following objectives:
1) Interpret degradation and transformation data from an extensive microcosms study initiated by
Line Lomheim;
2) Assess effect of pH on degradation and develop a biodegradation activity assay that could be
easily performed on samples on site;
3) Perform a comprehensive microbial community analysis using DNA amplicon sequencing data
from microcosms samples, activity assays, and field samples; and
4) Compile data and interpret results to recommend best course of action for remediation at the site
of interest.
Thesis structure
Chapter 1 contains the literature review and a brief introduction on the topics that will be discussed
throughout this thesis, as well the objectives and thesis structure.
Chapter 2 describes general materials and methods used during this research, including analytical
methods, sampling procedures, maintenance of microcosms, and bioinformatic techniques to analyze
microbial data results.
Chapter 3 explains the background for this study, which is a microcosm study that was set up first in
2015 with environmental material from the field site by Line Lomheim in the Edwards laboratory and has
7
been periodically monitored since that time. Degradation and transformation graphs are shown in this
chapter, in support of Objective 1.
Chapter 4 describes the laboratory activity tests conducted between 2016 and 2018, including results
from trainings performed at the site in Brazil, and experiments conducted at the University of Toronto
using enrichment cultures and pure cultures from collaborating universities. The influence of pH on
aerobic and anaerobic degradation and biotransformation are also shown in this chapter, in support of
Objective 2.
Chapter 5 explains the microbial community analysis, Illumina sequencing results and analysis, and the
statistical analysis that was performed on the samples. Changes in microbial community over time,
comparison between external pure cultures and microcosms samples, and other analysis are also in this
chapter, in support of Objectives 3 and 4.
Chapter 6 synthetizes the main findings and presents suggestions and recommendations for future work,
in support of Objective 4.
The appendices support the text and show raw data from different experiments. They also present graphs
and table with results and more technical information mentioned in the thesis.
8
Chapter 2 Materials and Methods
Preparation of Solutions
2.1.1 COI stock, sodium sulfate, sodium nitrate, and sodium lactate solutions
Contaminants stock solution
Multiple stock solutions were prepared during this work, as different mixtures of contaminants were
tested in the microcosms. Table B.1 shows the chemical compounds and solvents used to prepare the
stock solutions, as well as their purity and brand.
There were two types of stock solutions prepared with the COIs during this research: neat and dissolved
in solvent. The neat stock solutions were prepared by mixing the pure, undiluted compounds at a certain
concentration and then adding a small volume of this solution to the microcosm bottles. This technique
can be challenging when the volumes to be added are smaller than 3 µL, since it can be inaccurate to add
such small volumes to the bottles. Even though some compounds used for this research are solids, they
become liquid when combined. For example, after mixing the solids of 3,4-DCNB, 2,3-DCNB, and 3,4-
DCA, the mixture becomes a liquid and the neat stock solution can then be added to the bottles using a
syringe.
As these compounds are not very soluble in water (Table A.3), dissolving them in acetone is the best
option to increase the feeding volume, and therefore the accuracy of feeding. To avoid adding solvent in
the microcosms, some of the stock solutions were prepared in acetone but the acetone and COI solution
was not added to the microcosms directly. The desired volume of solution was dispensed onto a small
microscopy glass, left inside the fume hood until the acetone was completely evaporated (approximately 5
minutes), and then the glass was added to the microcosm bottles. After 24 hours, the contaminants were in
equilibrium with the liquid phase and therefore no solvent was added to the bottles. To add the glass slide
to the bottles anaerobically, it was necessary to open the microcosm bottles inside the glovebox, and any
gaseous losses during this process of opening and closing the bottles were assessed by collecting a sample
immediately after the 24-hour equilibrium period and checking if the VOC concentrations had decreased.
9
Sodium sulfate and sodium nitrate stock solutions
Some anaerobic microcosms were fed with either sodium sulfate or sodium nitrate stock solutions, that
would serve as electron acceptors. To achieve the concentration of 400 mM for both stock solutions, a
mass of 5.68 g and 3.39 g of Na2SO4 (MW=142.043 g/mol) and NaNO3 (MW=84.99 g/mol) were
measured, respectively. The compounds were added in a 100 mL glass bottle, topped with autoclaved
Mili-QTM water (Milipore Sigma, Oakville, ON, Canada) to 100 mL, and the solution was filtered using a
0.22 µm nylon syringe filter (Mandel Scientific, Guelph, ON, Canada) to another sterile glass bottle
capped with rubber stopper and aluminum crimped cap. The solutions were then purged for 20 minutes
with filtered N2 gas and stored anaerobically at room temperature.
Sodium lactate stock solution
To prepare a 0.7 M lactate stock solution, 6 g of sodium lactate (NaC3H5O3, MW = 112.06 g/mol) was
measured in a glass bottle. Mili-QTM water was used to complete the mass to 60 g, creating a 60% (w/w)
solution. The solution was then filtered using a 0.22 µm nylon syringe filter (Mandel, Canada) into
autoclaved bottles, sealed with rubber stoppers and aluminum crimped cap, and then purged for 20
minutes with filtered N2 gas and stored at room temperature.
2.1.2 Anaerobic mineral medium
Anaerobic mineral medium was used in some microcosms tests described in this thesis. To prepare 1L of
mineral medium, 10 mL of 2 mM phosphate buffer solution (27.2 g of KH2PO4 and 34.8 g K2HPO4 at pH
7.0 in 1 L of distilled water), 10 mL of salt solution (53.5 g of NH4Cl, 7.0 g of CaCl2×6H2O, and 2.0 g of
FeCl2×4H2O in 1 L of distilled water), 2 mL of 0.5 mM magnesium sulfate solution (62.5 g/L
MgSO4×7H2O), and 1 mL of redox indicator (1 g/L resazurin) were added into a glass screw cap bottle to
a volume of 970 mL. After the solution was autoclaved, the bottle was cooled in an ice bath and purged
with gas mix (80% N2, 20% CO2) for 30 minutes, and then transferred to the Vinyl Anaerobic Chamber
glove box (Coy Lab Products, Grass Lake, MI, USA). In the glove box, 1 mL of trace minerals solution
(500x), 10 mL of vitamins stock (100x), 10 mL of amorphous ferrous sulfide, and 10 mL of saturated
bicarbonate solution (100x) were added in that order to the bottle containing the autoclaved solution. The
protocols to prepare these medium stock solutions are described below. After adding all the medium stock
solutions, pH was measured, as described in Section 2.2.4, and the bottle was stored in the glove box to
allow for the settling of the amorphous ferrous sulfide.
10
Trace minerals solution
In a 160 mL serum bottle, the following were combined: 0.3 g of H3BO3, 0.1 g of ZnCl, 0.1 g of
Na2MoO4×2H2O, 0.75 g of NiCl2×6H2O, 1.0 g of MnCl2×4H2O, 0.1 g of CuCl2×2H2O, 1.5 g of
CoCl2×6H2O, 0.02 g of Na2SeO3, and 0.1 g of Al2(SO4)3×18H2O. Then, 1 mL of concentrated H2SO4 was
added to dissolve the compounds and distilled water was added to top up to 1 L. The bottle was sealed
with a rubber stopper and aluminum crimped cap and the solution was autoclaved and purged with N2 gas
for 20 minutes.
Vitamins stock solution
In a 1 L glass bottle, the following vitamins were added: 0.02 g of biotin, 0.02 g of folic acid, 0.1 g of
pyridoxine HCl, 0.05 g of riboflavin, 0.05 g of thiamine, 0.05 g of nicotinic acid, 0.05 g of pantothenic
acid, 0.05 g of para-aminobenzoic acid, 0.05 g of cyanocobalamin, 0.05 g of thioctic (lipoic) acid, and 1.0
g of coenzyme M. Deionized water was used to adjust the volume to 1 L and using 2 N NaOH, the
solution pH was adjusted to 7. This solution was then diluted 1:100 (v/v), filter sterilized into a 160 mL
serum bottle, sealed with a rubber stopper, crimped, and purged for 20 minutes with N2 gas.
Amorphous ferrous sulfide solution
Two initial solutions were prepared: FeSO4×7H2O (27.8 g/400 mL of anaerobic water) and Na2S×9H2O
(24 g/400 mL of anaerobic water). The anaerobic bottle was prepared by purging the desired volume of
water with N2 gas for 40 minutes. Inside the glove box, FeSO4×7H2O solution was added to the
Na2S×9H2O solution in a 1 L bottle, sealed immediately with a cap and septa, and shaken. The bottle was
removed from the glove box, purged for 40 minutes with N2 to remove the H2S gas formed during the
reaction, and returned to the glove box. The solution was divided into 4 Nalgene anaerobic centrifuge
tubes and centrifuged for 10 minutes at 4°C at 10,000 rpm. The supernatant was discarded, and the pellet
was resuspended with 200 mL of anaerobic water and centrifuged again. The resulting FeS suspension
from all 4 centrifuge tubes were combined into a 1 L bottle, sealed, and autoclaved.
Saturated bicarbonate solution
In a 160 mL serum bottle, 20 g of NaHCO3 was mixed with 100 mL of distilled water, covered with
aluminum foil and autoclaved. The bottle was capped with rubber stopped, crimp sealed, and purged for
15 minutes with N2 while cooling. This solution has a NaHCO3 precipitate that forms on the bottom of the
bottle which ensures saturation of NaHCO3 in the liquid phase.
11
Microcosm study
2.2.1 Microcosm study set up
The major microcosm study in this thesis was conducted using soil and groundwater from the industrial
site in Brazil. The experiment was set up in a flexible, inflatable polyethene glove bag (Aldrich-
AtmosBagTM) that allows the microcosms to be created anaerobically. Before setting up the glove bag, it
was necessary to wash, autoclave, and prepare the following materials: 250 mL clear Boston round glass
bottles (Scientific Instrument Services, Ringoes, NJ, USA), autoclavable bin covered with aluminum foil,
measuring spoons, funnel, mixing utensils, graduated cylinder, and glass beaker. MininertTM valves
(Chromatographic Specialties Inc., Brockville, ON, Canada) were washed and cleaned with alcohol wipes
or soaked in 70% ethanol bath for one hour before use.
The glove bag has two openings: an inlet and an outlet. Through the inlet, nitrogen gas and gas mix (80%
N2 and 20% CO2) would be alternated according to the need by switching the alternator between the two
gas cylinders. The outlet opening was connected to a vacuum pump. Anaerobic tape (3M™ Scotch-
Weld™ Anaerobic Adhesives) was used to seal the connections and to ensure no sure no gas was
escaping. The glove bag was set up inside the fume hood. The autoclaved items were placed inside the
glove bag while they were still warm, leaving them exposed to the laboratory atmosphere as little as
possible. The soil and groundwater samples were also placed inside the glove bag, along with the
MininertTM caps, and disposable material such as nitrile gloves, paper towels, autoclavable bags for waste,
permanent marker, scissors, and alcohol wipes. Once all the material was inside the glove bag, the main
opening was sealed with anaerobic tape.
The anaerobic gas composition inside the glove bag is 80% N2 and 20% CO2. To achieve this condition
inside the glove bag, it is necessary to flush the glove bag with N2 twice, by filling and deflating using the
N2 gas tank and the vacuum pump. The third fill is with the gas mix of 80% N2 and 20% CO2. A low flow
of the gas mix is maintained overnight to avoid bag deflation over the course of microcosms set-up.
Another gas mix deflation and inflation cycle was completed the following morning to maintain anaerobic
conditions. Figure 2.1 shows a scheme of the glove bag set-up in a fume hood.
12
All the bottles were set up by adding 4 spoons of soil (total of approximately 20 g) and 150 mL of
groundwater in Boston round bottles, caped with MininertsTM caps, leaving a headspace of approximately
100 mL. After the bottles were prepared and labeled, each received the respective treatment according to
the treatment table, Table 2.1. Both aerobic and anaerobic microcosms were prepared inside the glove
bag to avoid exposing the microcosms to the laboratory atmosphere, and oxygen was added to the aerobic
bottles when they were removed from the glove bag. In a microcosms study, groups of bottles receive
different amendments according to the objective of the project. For this study, they were set up in
triplicates in the following conditions:
Samples for pH, HPLC, and GC were taken after set-up of conditions, as described in the following
sections of this chapter. After the bottles received the assigned treatments, the anaerobic bottles were
transferred to the glove box (Coy Lab Products, USA) and the aerobic bottles were supplemented with
oxygen and were stored on a laboratory bench. All the microcosms were stored statically upside down to
avoid gas escaping through the MininertTM cap and covered with an opaque, black cloth to prevent
exposure to sunlight, to prevent photoreactions and photodegradation. The volumes of contaminants and
how they were added to the bottles is described in Chapter 3.
Figure 2.1 Microcosm study set up. Gas tanks (N2 and gas mix) are connected to the glove bag, which is
inside the fume hood, through plastic hose and alternating the gas cylinder as needed. Vacuum pump
deflates the glove bag to make sure the environment inside the bag is anaerobic. All the autoclaved
material, disposable material, and environmental samples are inside the glove bag and it is properly sealed
to start to set up.
13
Table 2.1 Treatment table for microcosms study #1
Treatment
Soil Ground-
water
Head-
space
Resazurin
(1g/L
stock)
HgCl2
(5%)
NaN3
(5%)
Vitamin
stock a
(N)
Salt
solu-
tiona
(P)
Phos-
phate
stocka
Lactate
stock b
(0.7M)
Ethanol
Sulfate
stock b
(400mM)
Nitrate
stock b
(400mM)
vol. in
mL* mL mL µL mL mL mL µL µL µL µL µL µL
Aer
ob
ic
Sterile controls
20 150 100 150 1.5 0.6
20 150 100 1.5 0.6
20 150 100 1.5 0.6
Active controls
20 150 100 150
20 150 100
20 150 100
Vitamin
amended
20 150 100 150 1.5 150 150
20 150 100 1.5 150 150
20 150 100 1.5 150 150
An
aero
bic
Sterile controls
20 150 100 150 1.5 0.6
20 150 100 1.5 0.6
20 150 100 1.5 0.6
Active controls
20 150 100 150
20 150 100
20 150 100
Electron donor
(ethanol &
lactate)
20 150 100 150 200 20
20 150 100 200 20
20 150 100 200 20
Sulfate amended
20 150 100 150 750
20 150 100 750
20 150 100 750
Nitrate amended
20 150 100 150 750
20 150 100 750
20 150 100 750 a Description of solutions in Section 2.1.2, in mineral medium preparation. b Description of stock solutions provided in Section 2.1.1
(*) soil from cores was added to the bottles, not slurry. Volume measured by spoons of soil.
14
2.2.2 VOC monitoring using GC
Dichlorobenzenes (1,2-, 1,3-, 1,4-DCB) and methane were analyzed using the Agilent 7890A gas
chromatograph (GC) with headspace autosampler G1888, equipped with a GSQ-Plot column (0.53 mm x
30 m) (both from Agilent Technologies, Santa Clara, CA, USA) and a flame ionization detector (FID).
The inlet is packed, at 200°C, and the carrier gas during the run was helium. The detector operates at
250°C, H2 flow was 40 mL/min, air flow was 400 mL/min, and total flow was 11 mL/min. The oven was
programed as follows: 35oC for 1.5 min, ramp 15oC/min to 100oC, ramp 5oC/min to 185oC hold 10 min,
ramp 20oC/min to 200oC, hold 10 min. The total run time is 43.6 min per sample vial and the retention
times are as follows: 0.92 min for methane, 15.16 min for benzene, 32.6 min for 1,3-DCB, 33.4 min for
1,4-DCB, and 34.4 min for 1,2-DCB. Standard curves these compounds are shown in Figure B.1.
The autosampler setting was as follows: oven at 70°C; loop at 80°C; transfer line at 90°C; vial
equilibration time 40 min; pressurization time: 0 min; loop fill time: 0.2 min; loop equilibration time: 0
min; inject time: 3 min; GC cycle time: 47 min; shaking: low.
Samples were collected using a 22G (0.7 mm x 40 mm) PrecisionGlideTM needle (BD, Franklin Lakes,
NJ, USA) attached to a Luer-Lock 2 mL Gastight® glass syringe (Hamilton Company, Reno, NV, USA),
and taken out of the glove box, for anaerobic samples. In the fume hood, clear glass flat bottom 10 mL
autosampler vials (Agilent Technologies, Santa Clara, CA, USA) were filled with 5 mL of acidified water
(2.4 mL of HCl 5 N topped up to 1 L with Mili-QTM water). The needle was placed into the acidified
water, the sample was rapidly dispensed, and the vial was crimped with an open top 20 mm aluminum
crimp seal with PTFE/silicone coated septum (200 mm, 130mil, white) (both from Chromatographic
Specialties Inc., Brockville, ON, Canada) by using a vial crimping tool.
2.2.3 SVOC monitoring using HPLC
Aniline, chloroanilines (2-, 3-, 4-CA), dichloroanilines (2,3-, 2,5-, 3,4-DCA), and dichloronitrobenzenes
(3,4-, 2,5-, 2,3-DCNB) were analyzed using a Hewlett-Packard/Agilent 1050 series high performance
liquid chromatograph (HPLC) system, combined with a quaternary pump and an autosampler (Agilent
Technologies, Santa Clara, CA, USA). The HPLC is equipped with an Acclaim™ 120 C18 column, 3 µm
particle size, 4.6 x 150 mm, with average pore diameter of 120 Å, attached to an AcclaimTM C18 guard
cartridge, with 5 µm particle size, 4.6 x 10 mm (both from Thermo Scientific, Waltham, MA, USA). The
UV detector is set for 254 nm, mobile phase contains 50% Acetonitrile and 50% Mili-QTM water
(Milipore Sigma) at a flow rate of 1 mL/min, isocratic flow.
15
Samples were collected using a 22G needle (BD) attached to a Luer-Lock 2 mL Gastight® glass syringe
and taken out of the glove box for anaerobic samples. In the fume hood, the needle was discarded, and an
ethanol pre-washed 0.22 µm Chromspec UV Syringe filter 13 mm (Chromatographic Specialties Inc.,
Brockville, ON, Canada) was attached to the syringe and a new 22G needle was attached. A 1 mL sample
was collected from the microcosm, for 0.5 mL of sample to be used to wash the filter and be discarded to
flush ethanol. The remaining 0.5 mL of sample was placed into a clear glass 350 µL flat bottom 6x31 mm
insert (Chromatographic Specialties Inc., Brockville, ON, Canada) until it was full, inside a clear 2 mL
autosampler glass vial (Agilent Technologies, Santa Clara, CA, USA). The remaining volume of sample
was trapped in the filter and was discarded. The vial was closed with a PTFE silicone coated cap (VWR,
Radnor, PA, USA). The HPLC run has a total time of 25 min per vial and the retention times are as
follows: 3.3 min for aniline, 4.9 min for 4-CA, 5.3 min for 3-CA, 5.38 min for 2-CA, 7.8 min for 3,4-
DCA, 9.0 min for 2,3-DCA, 10.0 for 2,5-DCA, 14.0 min for 2,3- and 2,5-DCNB (they elute in the same
peak in this method), and 16.5 min for 3,4-DCNB. Calibrations curves for these compounds are shown in
Figure B.2.
2.2.4 Other measurements: oxygen, pH, and sulfate and nitrate concentrations
Oxygen measurement
A Hewlett-Packard 5890 series gas chromatograph (GC) equipped with a thermal conductivity
detector (TCD) and an Alltech® CTR-I, 6’ x ½” column (Cole-Parmer, Montreal, QC, Canada), with
packed inlet was used to measure oxygen in the microcosms samples. The carrier gas used was helium,
oven temperature during the run is 50°C, and gas carrier flow was set for 180 kPa. Injector temperature
was 200°C during the run. 300 µL of aerobic microcosm headspace was sampled with a Pressure-Lok
gastight syringe (VICI Precision Sampling, Baton Rouge, LA, USA). Oxygen standards were run prior to
microcosm measurement.
pH measurement
A 22G needle was attached to a 1 mL Luer-LokTM tip syringe (BD, Franklin Lakes, NJ, USA) to
withdrawal 1 mL sample from the bottle for pH test. After collection, the sample was transferred into a
1.5 mL polypropylene microcentrifuge tube (Fisher Scientific Co., Markham, ON, Canada) and the pH
was measured by using a pH Spear meter (Oakton Instruments, Vernon Hills, IL, USA). Prior to
16
measuring samples, the pH meter was calibrated according to the manufacture’s protocol, using pH 4, pH
7, and pH 10 OrionTM buffer solutions (Thermo Scientific, Sunnyvale, CA, USA).
Sulfate and nitrate measurement in ion chromatography
Sulfate and nitrate concentrations in the microcosms were measured using a DionexTM ICS-2100 pump
(Ion Chromatography System), isocratic flow, starting column flow of 1 mL/min. The effluent used was
23 mM KOH. Suppressor type ASRS 4mm, current 57 mA. The pump is coupled with a DionexTM
IonPacTM AS18 analytical column (4x250mm) (Thermo Scientific, Sunnyvale, CA, USA). Standards were
prepared with the following concentrations: 0.005 mM, 0.01 mM, 0.05 mM, 0.2 mM, and 0.5 mM by
serial dilution. Retention times for the compounds measured in this method were: acetate 3.3 min,
chloride 4.5 min, nitrite 5.1 min, sulfate 6.8 min, nitrate 7.7 min, and phosphate 14 min.
Preparation of samples for DNA extraction
In addition to analysis of samples from microcosms bottles, samples were also collected directly from soil
and groundwater from the site. Groundwater and soil samples were collected from the site in Brazil and
shipped to Toronto for DNA extraction followed by Illumina Amplicon sequencing, as explained below.
2.3.1 Groundwater samples
Groundwater samples arrived at the University of Toronto in PTFE bottles and required preparation
before DNA extraction. These bottles were shipped in coolers with dry ice and remained under 4°C
during transit. The groundwater was filtered through a sterile SterivexTM 0.22 µm filter unit (EMD
Millipore Corporation, Billerica, MA, USA) until one liter was completely filtered or the filter got
clogged. After filtration, the filter was drained, sealed with parafilm and stored at -80°C until DNA
extraction. Figure 2.2 shows the filtration unit set up. When ready to extract the DNA, the SterivexTM
plastic casing was broken, the paper filter was cut and transferred to a microcentrifuge tube for DNA
extraction following DNeasy PowerSoil Kit (Qiagen, USA) protocol. DNA extracts from groundwater
were sent for amplicon sequencing at Genome Québec.
17
2.3.2 Soil samples
Soil samples arrived at the University of Toronto in plastic cores which were opened inside the glove bag
during microcosm study set up. At this point, approximately 0.25 g was collected in a 2 mL micro tube
PP (Mikro-Scharaubröhre, SARSTEDT AG & Co., Germany) for DNA extraction and then stored at -
80°C until DNA extraction. DNeasy PowerSoil Kit (Qiagen, USA) was used for soil samples according to
manufacturer’s protocol. DNA extracts from soil were sent for amplicon sequencing at Genome Québec.
DNA extraction, amplicon sequencing, and qPCR
Samples for DNA extraction were collected throughout the microcosm study, aiming to capture the
changes in the microbial communities. Over 100 samples were taken from the microcosms for DNA
extraction. To sample a microcosm for DNA extraction, 1 mL of groundwater was removed from the
bottle using a Luer-LokTM tip syringe coupled with a 22G needle, removed from the glove box, and
transferred to a 1.5 mL microcentrifuge tube to be centrifuged at 10,000 rpm for 25 minutes. The
supernatant was transferred to another microcentrifuge tube which was stored at -80°C for further
analysis. DNA extractions were done on the pellet using DNeasy PowerSoil Kit (Qiagen, USA) following
the manufacture’s protocol. DNA was eluted with UltraPureTM Distilled water (Invitrogen, Grand Island,
NY, USA) and quantified using a Thermo ScientificTM NanoDropTM Spectrophotometer (Thermo Fisher
Scientific, Waltham, MA, USA).
Vacuum pump
Sterivex fitter
Sample Fume hood
Loading unit
Figure 2.3 Groundwater filtration set up. Filtration unit was set up inside the fume hood by
connecting a loading unit, such as 60 mL syringe without the plunger, to the Sterivex filter and to the
vacuum pump.
18
After DNA extraction, the extracts were sent for Illumina MiSeq PE300 16S rRNA amplicon sequencing
at Genome Québec using forward primer 926f modified (5’-AAACTYAAAKGAATWGRCGG-3’) and
reverse primer 1392r modified (5’-ACGGGCGGTGWGTRC-3’). These primers amplify nearly 500 base
pairs of the 16S rRNA gene to target bacteria, archaea, and 18S rRNA gene of some eukaryotes. MiSeq
reagents kit produces about 25 million reads per run and depending on the number of samples that are
added to each plate, the final number of reads per sample will vary. Amplicon sequencing results were
processed in MetaAmp and will be explained in Section 2.5
The total copies of bacteria and archaea in each sample was quantified by quantitative polymerase chain
reaction (qPCR) using a CFX96TM real-time PCR detection system, with a C1000 thermocycler (Bio-Rad
Laboratories Inc., Hercules, CA, USA). Reactions had a total volume of 20 µL, being 10 µL of SsoFastTM
EvaGreen® SuperMix (Bio-Rad Laboratories Inc., USA), 0.5 µL of each forward and reverse primers
(concentration of 500 nM for both primers), 7 µL of UV treated UltraPureTM Distilled water (Invitrogen,
USA), and 2 µL of DNA extract diluted 1 in 10, using the same water to avoid and reduce any inhibitory
effects from the matrix. Each sample was run in triplicates and negative controls were run to identify any
contamination between the samples. R2 values were 0.99 or greater and efficiency values 87-100%.
For general bacteria runs, the cycles were as follows: 98°C for 2 min, 40 cycles of 98°C for 5 seconds and
55°C for 10 seconds, followed by an increase from 65°C to 95°C at 0.5°C increments over 10 seconds.
For general archaea, the cycles were as follows: 98°C for 2 min, 40 cycles of 98°C for 5 seconds and
60°C for 10 seconds, followed by an increase from 65°C to 95°C at 0.5°C increments over 10 seconds.
Standards were applied to each plate, using serial dilutions of target-containing plasmids between 101 and
108 gene copies/mL. Samples were analyzed using general bacteria 16S rRNA primers GenBac1055f (5’-
ATGGYTGTCGTCAGCT-3’) and GenBac1392r (5’-ACGGGCGGTGTGTAC-3’). To analyze general
archaea 16S rRNA, the primers were: GenArch787f (5’-ATTAGATACCCGBGTAGTCC-3’) and
GenArch1059r (5’-GCCATGCACCWCCTCT-3’). The final copy number per mL was calculated by
multiplying the total mean starting quantity values from qPCR in copies/µL, the dilution factor, and the
elution volume during DNA extraction (in µL), divided by the amount of culture filtered (mL).
Statistical analysis: MetaAmp and RStudio
To perform statistical analyses and identify relationships in the microbial community at the site, all of the
microcosms, groundwater, soil, and enrichment culture samples were sent for sequencing of 16S rRNA at
Genome Québec. After obtaining these results, the FASTA files were processed using MetaAmp version
19
2.0. MetaAmp is a pipeline for processing the small subunit (16S) of ribosomal ribonucleic acid (SSU
rRNA) genes and other amplicon sequencing data. This pipeline accepts both single-end or paired-end in
FASTA or FASTAQ files and uses UPARSE, Mothur, and SILVA databases for clustering, removal of
chimeric reads, taxonomic classification, and generation of diversity metrics (Dong, et al., 2017). This
pipeline is an online tool to manipulate the data computationally, similarly to other tools such as Mothur
or QIIME. The steps for using MetaAmp are: a) filter out poor quality sequences, b) trim off sequences
adapters and barcodes, c) merge each pair-ended read into a single sequence, d) assign sequences based
on barcodes, and e) cluster sequences using 97% similarity cut-off based on databases. The output files
from this program can be used as inputs for other software for further manipulation, such as RStudio and
Excel, which were used for these analyses.
To analyze sequencing data, the input parameters used in MetaAmp were: sequence format “fastq”,
sequencing type “paired-ended”, forward primer 5’-AAACTYAAAKGAATWGRCGG-3’, reverse
primer 5’-ACGGGCGGTGWGTRC-3’, marker gene type rRNA gene, similarity cutoff 0.97. For paired-
ended merging options the minimum length of overlap was 30 and maximum number of mismatches in
overlap region was 3. For quality filtering options, maximum number of differences to the primer
sequence was zero, maximum number of expected errors was 1, and trim amplicon was set to a fixed
length of 430. After selecting the parameters and uploading the result files, a link is generated, and the
results are available online after a few hours.
Once the sequencing data was processed in MetaAmp, the statistical analysis was conducted in RStudio,
using the Phyloseq and Vegan packages. The scripts used to run the samples can be found in Appendix
F. The statistical methods used to analyze the data was non-metric multidimensional scaling (NMDS) and
is described in Chapter 5.
Road map of experiments conducted during this research
Since multiple experiments were conducted during this research, in different locations, and with help
from other colleagues, Figure 2.3 below represents a road map to guide the reader through the next
chapters, including methodology and results from each of the experiments.
20
Figure 2.3 Road map for experiments in this research. The time line above shows all the experiments conducted during this research, as well as
their location in the thesis.
21
Chapter 3 Background: Microcosm study #1
Motivation and sample location
In 2015, the University of Toronto received soil and groundwater samples from the site in Brazil to
conduct a microcosm study. The objective of this study was to identify certain conditions under which
specific microorganisms would grow and possibly biodegrade contaminants of interest (COIs) and then,
in the future, apply such conditions in the site to have the contaminants degraded to acceptable national
and international levels, as shown in Table A.1 and A.2. These conditions could also affect the rate of
compounds degradation in contaminated ecosystems. This would provide guidance to better understand
optimal conditions for bioaugmentation in the site.
The samples were collected from two different locations in the site (Site 1 and Site 2), and two different
depths (A being shallow, B being deep), resulting in four different sites (1A, 1B, 2A, and 2B). Figure 3.1
shows the locations where groundwater and soil samples were collected from, Figure C.1a shows the soil
physical description when they arrived at the University of Toronto, and Figure C.1b shows their
respective depths and target COIs.
Methodology and COIs
The detailed methodology on how the microcosm study was set up, maintained, and sampled was
provided in Section 2.2. Please refer to Table 2.1 for the list of microcosm bottles and conditions. In this
section, specific characteristics of the microcosms study will be explained and discussed.
When the environmental samples arrived at UofT, groundwater samples were analyzed for semi volatiles
organic compounds (SVOCs) to assess initial concentration of COIs: PM19 did not show any
contamination and PM12 showed 0.55 mg/L of 2-CA, 0.29 mg/L of 2,3-DCA, 0.28 mg/L of 2,5-DCA,
and 4.67 mg/L of 3,4-DCNB, which were low compared to site historical information. The average for
these compounds in groundwater samples were: 9.68 mg/L for 2-CA, 14.4 mg/L for 2,3-DCA, and 3.5
mg/L of 2,5-DCA. Because of the low initial concentrations, 100 mL of natural groundwater was
removed and replaced with an equal volume of artificial groundwater containing COIs in order to reach a
target concentration of 5 mg/L of each specific COI per bottle.
22
Figure 3.1 Sample location for microcosm study #1. Soil and groundwater collected from NPAD (Site
1, borehole N083, groundwater well PM-19) and from UN11&12 (Site 2, borehole N082, groundwater well
PM-12). Samples collected in 2015 and shipped to University of Toronto under refrigerated conditions.
Figure prepared by CH2M.
Based on site historical information, it was decided that the COIs would be added to the microcosms
according to Figure C.1b: site 1A would receive dichlorobenzenes and dichloroanilines; 1B would
receive only dichlorobenzenes; site 2A would receive chloroanilines, dichloroanilines, 2,5-DCNB, and
3,4-DCNB; and site 2B would receive dichloroanilines, 3,4-DCNB, and 2-CA that was naturally present.
Site 1 has shown overall higher concentrations of COIs when compared to the other location: the average
of 1,2-DCB in soil was 111 mg/kg and in groundwater was 2025 µg/L, whereas in Site 2 the soil sample
showed 67 mg/kg and the groundwater, 1704 µg/L. Dichloroanilines were found in high concentrations in
both sites, whereas DCNBs were higher in Site 2, for both soil and groundwater matrixes, as shown
previously in Table A.1 and Table A.2. All the bottles were fed with neat stock solutions, using different
Luer-Lock Gastight® glass syringes. The concentrations of COIs ranged from 5 to 15 mg/L in the bottles,
depending on the site and historical information.
Analytical and molecular samples were routinely collected from microcosms to assess the COI
concentrations and microbial community compositions, as explained in Section 2.2.2 (VOC monitoring
using GC), Section 2.2.3 (SVOC monitoring using HPLC), and Section 2.4 (DNA samples). The
analytical results from HPLC and GC analyses are discussed in the next section and DNA results are
Figure prepared by CH2M
23
discussed in Chapter 5, where 16S rRNA sequences from microcosms samples were compared to other
types of samples.
Results and discussion
3.3.1 Aerobic microcosms
In this study, complete aerobic biodegradation of aniline, 2-CA, 3-CA, 4-CA, 2,3-DCA, 3,4-DCA, and
1,2-DCB occurred in specific sets from the site. Table 3.1 summarizes the aerobic biodegradation
observed in the bottles and in which treatment the degradation occurred. Active controls bottles have
shown degradation of aniline, all chloroaniline isomers, and 1,2-DCB in all the sites they were tested (1A,
2A, and 2B). DCNBs did not degrade aerobically, neither did 1,3- and 1,4-DCB. The reactions that
occurred in the active controls were the same as the vitamin amended bottles, which means that adding
vitamins had no apparent effect in inhibiting or enhancing any of the biodegradation processes observed.
Table C.1 summarizes average of aerobic degradation rates in active microcosms. The rates were
calculated using the concentration plot for each microcosm where X axis is time (in days) and Y axis is
concentration (mg/L) as follows: subtracting the compound concentration from a certain point B to point
A, and dividing this result by the subtraction of time B minus time A. The rate result is given in mg/L/day
and it was calculated when degradation was occurring in a specific bottle. In some microcosms, the
triplicates did not behave the same, so the rate was calculated in one microcosm (no deviation presented).
All these bottles received oxygen during incubation as explained in Section 2.2.4, so this was not a
limiting condition for the microorganisms to degrade these compounds. The pH was not adjusted during
this microcosm study, and the pH range in these bottles was 4.6 to 6.5. Because natural pH in the site is
low, a few tests adjusting the pH to neutral were conducted as described in Chapter 4. In some of these
experiments degradation of 3,4-DCNB only started after pH was adjusted to neutral, whereas
biodegradation of 1,2-DCB occurred either before and after pH adjustment (Section 4.4).
In general, acidic pH might affect the rate of aerobic and anaerobic biodegradation, since all
microorganisms are pH sensitive, and tend to have specific optima. As the site has low pH in general, it is
important to perform tests with both acidic and neutral pH to determine if neutral pH enhances
biodegradation.
Figure 3.2 illustrates the time trend for degradation in an aerobic active control bottle from site 1A. This
microcosm, which was amended with 2-CA, DCAs, and DCBs, was able to completely degrade 2-CA,
2,3-DCA, and 3,4-DCA completely after 160 days; partial degradation of 2,5-DCA was also observed. 2-
24
CA initial concentration was approximately 8 mg/L and was biodegraded in a rate of 0.78 mg/L/day
whereas 2,3-DCA had initial concentration less than 2 mg/L and had a degradation rate of 0.86 mg/L/day.
2,5-DCA concentrations started at 1.5 mg/L/day and it was re spiked in the bottles four times and it did
not show complete degradation in any of them, always stopping after approximately 50% was degraded.
For this site, the average pH was 5.6 and it did not change over time.
Table 3.1 Summary of aerobic biodegradation observed during main microcosm study. CA =
chloroaniline, DCA = dichloroaniline, DCNB = dichloronitrobenzene, DCB = dichlorobenzene
To make sure the degradation was occurring and to keep the bottles active, some of the compounds that
were degraded were re spiked in the microcosm on days 165, 197, 319, and 424. The compounds 2-CA,
2,5-DCA, and 2,3-DCA were added and the biodegradation occurred as the previous cycles, degrading
2,3-DCA and 2-CA completely, and slowly degrading 2,5-DCA.
Figure C.2 shows the time trend for degradation in aerobic microcosms from site 2B. Aniline, 1.2-DCB,
DCAs, and CAs are being degraded and were refed in order to keep the microcosms active.
In this study, the triplicates behave similarly, but not necessarily the same for all the treatments described
above. The complete data file and more degradation graphs for all the microcosms can be found in
Syntrophy folder in OwnCloud. More details about the files can be found in Appendix G.
1A 1B 2A 2B
Aniline ✔ nt nt nt AC/ Vit
2-CA ✔ AC/ Vit nt AC/ Vit AC/ Vit
3-CA ✔ nt nt AC/ Vit AC/ Vit
4-CA ✔ nt nt AC/ Vit AC/ Vit
2,3-DCA ✔ AC/ Vit nt AC/ Vit AC/ Vit
2,5-DCA* ✔ AC/ Vit nt AC/ Vit AC/ Vit
3,4-DCA ✔ AC/ Vit nt AC/ Vit AC/ Vit
2,3-DCNB ✖ - nt - -
2,5-DCNB ✖ - nt - -
3,4-DCNB ✖ - nt - -
1,2-DCB ✔ AC/Vit - AC/ Vit AC/ Vit
1,3-DCB ✖ - - nt nt
1,4-DCB ✖ - - nt nt
AC = active control / Vit = vitamins/ nt = not tested in this set
* = not complete degradation
✔ = degraded / ✖ = not degraded
Aniline and
chloroanilines
Dichloro-
nitrobenzene
Dichloro-
benzene
Site where reaction ocurredSummary of biodegradationContaminantGroup
25
Figure 3.2 Concentration versus time in an aerobic active control microcosm from site 1A. X axis show the elapsed time (in days)
since the beginning of the experiment and Y axis represent the contaminants concentration (mg/L) for each compound tested. Figure
prepared by Line Lomheim.
26
3.3.2 Anaerobic microcosms
There were five treatments in these bottles: sterile controls, active controls, electron donor amended,
sulfate amended, and nitrate amended. Under anaerobic conditions, the halogenated COIs could either be
electron acceptors (hence addition of donor), or electron donors (hence addition of acceptors like sulfate
or nitrate)
In this study, anaerobic biotransformation of several compounds occurred: 2,3-DCA, 2,5-DCA, 3,4-DCA,
2,5-DCNB, 3,4-DCNB, 1,2-DCB, 1,3-DCB, and 1,4-DCB in specific sets and treatments in the bottles.
Table 3.2 summarizes the anaerobic reactions observed during the study. Table C.2 shows the average
anaerobic transformation rates observed in these microcosms.
Table 3.2 Summary of anaerobic reactions observed during main microcosm study. CA =
chloroaniline, DCA = dichloroaniline, DCNB = dichloronitrobenzene, DCB = dichlorobenzene
Dichloronitrobenzenes (2,5-DCNB and 3,4-DCNB) were only tested in sites 2A and 2B and were
transformed to 2,5-DCA and 3,4-DCA respectively, in active control, electron donor amended, sulfate
amended, and nitrate amended microcosms from site 2A and only in active control from site 2B.
Dichloroanilines were tested in sites 1A, 2A, and 2B, and were only transformed in the shallow sites (1A
in electron donor amended bottles, and in site 2A in donor and sulfate amended bottles). It is important to
mention that 2,5-DCA did not degrade completely: in site 1A the concentration stabilizes at
approximately 2 mg/L and in site 2A, at 9 mg/L). 1,2-DCB degraded mostly in electron donor amended
bottles, and only after over 800 days of microcosms study, the other two isomers (1,3-DCB and 1,4-DCB)
showed degradation in nitrate amended bottles, in site 1B that was not tested for any other compound
anaerobically (Figure C.3).
1A 1B 2A 2B
Aniline ✖ nt nt - -
2-CA ✖ - nt - -
3-CA ✖ nt nt - nt
4-CA ✖ nt nt - nt
2,3-DCA ✔ Don nt Sulf -
2,5-DCA* ✔ Don nt - -
3,4-DCA ✔ Don nt Don, Sulf -
2,3-DCNB not tested nt nt nt nt
2,5-DCNB ✔ nt nt AC, Don, Sulf, Nit Don
3,4-DCNB ✔ nt nt AC, Don, Sulf, Nit Don
1,2-DCB ✔ Don Nit Don -
1,3-DCB ✔ - Nit nt nt
1,4-DCB ✔ - Nit nt nt
AC = active control / Don = donor amended / Sulf = sulfate amended / Nit = nitrate amended / nt = not tested in this set
* = not complete reaction
✔ = degraded / ✖ = not degraded
Aniline and
chloroanilines
Dichloro-
nitrobenzene
Dichloro-
benzene
Site where reaction ocurredSummary of biotransformationContaminantGroup
27
These results the difference between aerobic and anaerobic reactions in the environment. Aerobic
reactions tend to happen faster and have a shorter lag period at the beginning of the experiments, and
degradation does not produce detectable transformation products. In contrast, anaerobic reactions in this
study proceed via dichlorination or nitro-group reduction (in the case of the DCNBs). However, the
products of anaerobic reduction reaction were amenable to aerobic degradation. This indicates that natural
attenuation at the site might be occurring in both aerobic and anaerobic regions.
Figure C.4 shows the SVOCs in an electron donor amended anaerobic microcosm from site 1A where
degradation of 2,3-DCA, 3,4-DCA, and 1,2-DCB was observed. 3,4-DCA was dechlorinated to 4-CA
whereas 2,3-DCA transformation led to the transient production of 3-CA. 2,5-DCA was also being
transformed in this bottle, but not completely,
Figure C.5 shows VOCs from the same anaerobic electron donor amended microcosm as Figure C.4.
This bottle has shown 1,2-DCB transformation, but not 1,3-DCB and 1,4-DCB. While 1,2-DCB was
being dechlorinated to MCB, methane was also being produced from fermentation of excess lactate and
ethanol.
In site 2A, besides all the chloroanilines and dichloroanilines tested, dichlonitrobenzenes were also added.
While chloroanilines were not degraded, electron donor amended bottles have shown two different
reactions occurring in them. The first reactions occurred around day 233 and they were the transformation
of 2,5-DCNB to 2,5-DCA and 3,4-DCNB to 3,4-DCA. The DCNBs were re spiked in the bottle after 60
days of the first cycle and the same reactions occurred again, as shown in Figure 3.3. For over 500 days
of experiment, these were the only reactions taking place in these bottles, until 3,4-DCA was
dechlorinated to 3-CA. 2,3-DCA and 2,5-DCA concentrations also decreased at the same time as 2-CA
concentration increased. When looking at the GC graph for VOCs for these same bottles (Figure C.6),
1,2-DCB was naturally present in this bottle and its concentration also decreased while MCB
concentrations were increasing. The other two isomers of DCB were not added to the bottles and their
concentrations are under detection limits.
Both aerobic and anaerobic microcosms exhibit lag periods before the onset of degradation. This occurs
likely because the numbers of active microorganisms able to degrade the contaminants is very low
initially. Only after these microbes grow sufficiently is degradation detected. Overall, microcosms from
sites 2A and 2B were the most active, showing both aerobic and anaerobic transformations. Microcosms
from site 1A also exhibited significant aerobic degradation, as presented in Tables 3.1 and 3.2. Therefore,
28
the DNA samples collected from these sites are most likely to have the highest potential to yield
information on the microorganisms involved in these reactions. These results are discussed in Chapter 5.
29
Figure 3.3 Concentration of SVOCs versus time in anaerobic electron donor amended microcosm from site 2A. X axis show
the elapsed time (in days) since the beginning of the experiment and Y axis represent the contaminants concentration (mg/L) for
each compound tested. Figure prepared by Line Lomheim.
Figure 3.5 Concentration of SVOCs versus time in anaerobic electron donor amended microcosm from site 2A. X axis show
the elapsed time (in days) since the beginning of the experiment and Y axis represent the contaminants concentration (mg/L) for
30
Chapter 4 Laboratory activity tests
Four experiments were conducted in order to address specific questions about i) aniline and chloroaniline
transformation in anaerobic microcosms, ii) development of an activity test that could be performed on
site, iii) work with samples from collaborating universities, and iv) effect of pH on aerobic degradation
using a variety of different samples.
Aniline and chloroaniline anaerobic microcosm study #2
4.1.1 Motivation and sample collection
In February 2017, the University of Toronto received new soil and groundwater samples from the field
site to conduct more experiments. As anaerobic degradation of aniline, 2-, 3-, and 4-chloroaniline were
not extensively assessed during the study previously described in Chapter 3, it was decided that a new set
of microcosms would be prepared to study these compounds and their potential for bioremediation and/or
biotransformation under anaerobic conditions.
Soil and groundwater samples were collected from the DW-05 well, located downstream from NPAD, as
shown in Figure D.1, at approximately 48 meters below ground surface (mbgs). This is a very deep well
(the first sample at this depth in this study), and therefore possibly a better candidate for anaerobic
activity. Four days after collection, groundwater samples arrived in Toronto in 1L PTFE bottles with no
headspace and soil samples arrived in glass jars, with minimal headspace. Samples were kept at 4°C
during transit from Camaçari, Brazil to Toronto, Canada.
4.1.2 Methodology
When the site material arrived in Toronto, the groundwater was sampled for SVOC concentration as
described in Section 2.2.2, which were below detection limit for all the COIs analyzed. DNA samples
from soil and groundwater were also collected at this point, as described in Section 2.3. The methodology
to prepare this experiment is similar to that described in Section 2.2.1. More details about this specific
microcosm study is presented in Appendix D (page 104) and the treatment table presented on Table D.1.
31
4.1.3 Results and discussion
After sampling and maintaining the bottles, the concentrations were plotted, and the results are shown in
Figure D.2. None of the bottles showed degradation or transformation of anilines and chloroanilines, not
even when adjusting the pH to neutral. In these graphs, consistency, precise analytical procedures and
reproducibility of the measurements can be seen.
The DNA extracts showed low DNA concentrations, measured by the NanoDrop, of 2.90 ng/µL in soil
and 4.20 ng/µL in groundwater samples. Amplicon sequencing from Genome Québec failed due to low
DNA concentrations. As the samples were collected from deep surfaces in the site, it is possible that there
is a low abundance of microorganisms that can survive in such depths. Low abundance of
microorganisms could also be a reason why no degradation or transformation was observed in the bottles.
Aerobic degradation experiments of multiple COIs in Camaçari laboratory, Brazil
4.2.1 Motivation and sample collection
On location at the field site, there is an operating laboratory, capable of performing analytical and
biological analyzes in environmental samples. Carrying out activity tests on-site would preclude the need
to ship samples elsewhere, and thus would represent a huge advantage and cost saving, not to mention
empower local technical expertise to investigate the site. An aerobic degradation experiment with 5 COIs
(1,2-DCB, 2,3-DCA, 3,4-DCA, 2,3-DCNB, and 3,4-DCNB) was designed and conducted at the Camaçari
site in July 2017. I travelled to Camaçari to conduct this experiment with help from Olivia Molenda,
Isabela Camargo, and Ligia Carvalho.
The objectives of this experiment were to:
a. Train scientists and engineers on site on treatability study set up, and culture maintenance and
monitoring;
b. Prepare protocols for future degradation tests on site; and
c. Evaluate the potential for aerobic biodegradation of COIs that are present at the site.
As this was the first time that degradation experiments were performed on the site, the methodology and
procedures were tested. To do so, a water sample was collected from a puddle close to the NPAD, a
heavily contaminated area of the site. The sample was collected on the same day as the experiment set-up.
For further experiments, groundwater samples would be used to assess the potential for biodegradation.
32
No soil was added to the bottles in this experiment, since the purpose was to understand and train local
employees on the step by step protocol to carry out this kind of test and adapt the methodology to what
was available at the site.
4.2.2 Methodology
Since these experiments had never been conducted on site, the experiment was designed according to the
materials and equipment already available on site. To collect the water sample, a clean PTFE bottle was
used, and 1 L of puddle water was collected (puddle water was easily available and suitable for the
experiment objectives). The experiment was conducted inside the fume hood, in triplicates, in a total of 9
Boston round bottles (250 mL capacity each), with MininertTM caps, and the treatments were as follows
and are also shown in Table D.2:
a. Sterile controls: 100 mL of tap water was boiled for 15 minutes inside a beaker, on a hot plate (no
autoclave on site when the experiment was conducted), and no pH adjustment;
b. Active controls: 100 mL of puddle water without pH adjustment (pH of puddle water was 9.2);
c. pH-adjusted bottles: 100 mL of puddle water with pH adjustment using phosphate buffer solution
(0.2 M final concentration; prepared by adding 1 mL of 2.72 g KH2PO4 and 3.483 g K2HPO4 in
100 mL of MiliQ water, filter sterilized into a glass bottle). Final pH after adjustment was 7.14.
Since the puddle water did not contain any of the contaminants at the time of sampling, the COI stock
solution was added to this bottle. To prepare the COI stock solution, 3,4-DCNB, 2,3-DCNB, and 3,4-
DCA solids were added in that order, and when 3,4-DCA was added to the glass vial, the solids became a
brown, oily liquid. The glass vial was capped with a MininertTM cap, and then 2,3-DCA and 1,2-DCB
liquids were added by measuring the mass of the liquids inside syringes. The target concentrations were:
15 mg/L of 3,4-DCNB, 10 mg/L of 2,3-DCNB, and 5 mg/L of 1,2-DCB, 2,3-DCA, and 3,4-DCA. In each
Boston round bottle, 3 µL of the COI stock solution was added using a 5µL Luer-lock Gastight® glass
syringe.
Five samples were collected during the experiment on days 0, 5, 12, 19, 27, and they were analyzed by
GC and HPLC. An Agilent 5890 Series GC equipped with an Agilent Technologies capillary column
(DB-5MS, 60 m x 0.32 mm x 1µm), coupled with a flame ionization detector (FID), split mode 1:25 was
used to analyze 1,2-DCB concentrations.
33
To analyze 2,3-DCA, 3,4-DCA, 2,3-DCNB, and 3,4-DCNB, an Agilent Technologies HP-1100 Series
HPLC, coupled with a C8 column (4.6mm x 150mm x 3.5 Å particle size), UV-VIS detector using a 254
nm wavelength, flow rate of 1 mL/min in gradient mode, with a methanol-water mobile phase was used.
The gradient was as follows: (1) time zero: 55% H2O and 45% methanol, (2) 3 min: 55% H2O and 45%
methanol, (3) 15 minutes: 50% H20 and 50% methanol, and (4) 30 minutes: 100% methanol.
Samples for GC analysis were collected as follows: 1 mL of liquid sample was collected from the bottle
using a Luer-lock Gastight® glass syringe, dispensed into a 20 mL glass vial with 10 mL of NaCl
solution (pH=2), capped with silicon / PFTE cap, and left in the oven at 90°C for 15 minutes. The vial
was shaken and left for an additional 15 minutes in the oven, and then 1 mL of the headspace was
sampled and injected into the GC for analysis.
Samples for HPLC were collected as follows: 1 mL of liquid sample was collected from the bottle using a
Luer-lock Gastight® glass syringe, and then mixed with 1 mL of acetonitrile in a 2 mL glass vial. The
solution was then filtered through a 0.45 µm pore Millex HV 13mm filter (Millipore Industria e Comercio
Ltda., Barueri, Brazil) and the filtrate was placed in the HPLC glass vial for analysis.
Oxygen was not measured in the bottles during the experiment because the laboratory did not have an
oxygen meter at the time of the experiment. For further experiments, it was recommended that the bottles
could be opened inside the fume hood for about 5 minutes to ensure that oxygen was not a limiting factor
for aerobic biodegradation. Another possibility is to inject oxygen by using a syringe and needle through
the MininertTM cap.
4.2.3 Results and discussion
After 27 days of experiment, GC and HPLC results were plotted and the results are shown in Figure D.3.
As expected, the sterile controls did not show any discernable changes in concentrations of COIs, since
the water used in the experiment was boiled. These results illustrate reproducibility and consistency in
analytical methods.
In active controls without pH adjustment 3,4-DCA was completely degraded within the first 12 days of
the experiment, at a degradation rate of approximately 0.37 mg of 3,4-DCA/L/day. In addition, 2,3-DCA
was completely degraded after 19 days, at degradation rate of 0.16 mg of 2,3-DCA/L/day. Both 2,3- and
3,4-DCNB were not degraded completely over the 27 days of the experiment, however, the 3,4-DCNB
concentration was decreasing at a rate of 0.2 mg of 3,4-DCNB/L/day. Whereas the 2,3-DCNB
34
concentration had decreased only 16% of the initial concentration. It is likely that there would have been
further degradation observed in these bottles if the time course of the experiment was longer.
Overall, faster rates of COI degradation were observed in the pH-adjusted active controls. In these bottles,
the 3,4-DCA concentration was degraded at an estimated rate of 0.9 mg of 3,4-DCA/L/day. This is an
estimated rate because at the time of sampling, the concentration was already 0.0 mg of 3,4-DCA. The
second fastest COI that degraded completely was 2,3-DCA, with a degradation rate of 0.39 mg of 2,3-
DCA/L/day. While the other COIs were not completely degraded at the end of the experiment, the
concentration of these compounds was still decreasing, indicating biodegradation.
These results show a high potential for bioremediation at the site if oxygen is available. Adjusting the pH
to 7 may accelerate the degradation of COIs, but more experiments should be conducted with
groundwater samples from the site to assess the distribution of the microbial community responsible for
biodegradation. Furthermore, aerobic biodegradation of DCNBs has been reported by Palatucci (2017)
using samples from the site.
Highly enriched cultures from collaborating laboratories
4.3.1 Motivation and samples
As previously mentioned, collaborating universities and laboratories are involved in this remediation
project, studying different techniques using environmental samples from the Camaçari site. Two
laboratories in the United States, at the Clemson University and the University of West Florida, have
prepared enrichment cultures and pure cultures using water and sediment from the site, and from a water
treatment plant near the site, managed by Cetrel. The objective of this experiment was to compare the
microbial communities from enrichment cultures, which are known to degrade the COIs aerobically, to
the microbial communities found in the microcosms at the University of Toronto, in the Edwards
laboratory. The only anaerobic enrichment culture received for this experiment, from Clemson
University, was degrading 4-nitrotoluene, a compound that was not tested during this research.
Under the supervision of Dr. David Freedman, Quintero (2016) conducted a microcosm study using
environmental samples from the Camaçari site. Transfers were made from the microcosm bottles that
were degrading or transforming the COIs. Enrichment cultures were created that degraded chlorobenzene
and 1,2-DCB aerobically, and biotransformed 4-Nitrotoluene (4-NT) to benzylamide anaerobically, when
lactate was added as an electron donor. After the parent compounds were degraded in the microcosms,
and several re-amendments, transfers were made to new bottles with fresh groundwater to enrich activity.
35
The aerobic enrichment culture was fed, and pH was adjusted to neutral, then incubated on shaker at room
temperature. The anaerobic culture conditions were similar, except these bottles were incubated inside an
anaerobic chamber with a stir bar, at room temperature after pH adjustment. From these bottles, three
DNA extracts were sent to the University of Toronto in 2017: a) aerobic CB degrading, b) aerobic 1,2-
DCB degrading, and c) anaerobic 4-NT transforming. These DNA extracts were immediately stored at -
80°C until 16S rRNA sequencing.
A student in the research group of Dr. Jim Spain, at the University of West Florida, conducted a
microcosm study with samples from the site, and prepared enrichment cultures that aerobically degraded
2,3-DCNB, 3,4-DCNB, 1,2-DCB, and CB. The environmental samples were used as the inoculum of a
fluidized bed bioreactor (FBR). The enrichment cultures were maintained at neutral pH and incubated at
room temperature in a shaker. Pure cultures of DCNB isomer-degrading microorganisms were isolated as
described in Palatucci (2017). From these experiments, samples were sent to the University of Toronto in
2017: (a) agar plates containing both 3,4-DCNB- and 2,3-DCNB-degrading pure cultures, and (b) sand
samples from the FBR, containing chlorobenzene- and 1,2-DCB-degrading microorganisms. Before using
these various cultures in my experiments as test inocula and for DNA extraction, they were cultivated at
University of Toronto, as described in the Appendix D and shown in Figure D.4.
4.3.2 Methodology
After growing the external cultures from the University of West Florida, some of the Toronto microcosms
(from Chapter 3) that were not degrading specific COIs were inoculated with the culture mix to test if
bioaugmentation could work. The goal of this inoculation was to evaluate the potential for biodegradation
in these bottles if the appropriate microorganisms were present.
From site 2A, triplicates of active controls microcosms were combined, then split into 8 bottles, and each
pair of duplicates received treatments as shown in Table D.3. The treatments were: a) continuing with
maintenance as done in microcosms study #1, b) pH-adjusted to 7, c) inoculated without changing the pH,
and d) both inoculating and adjusting the pH to neutral. The pH was adjusted by adding bicarbonate
solution using a 1 mL plastic Luer-LokTM tip syringe (BD) coupled with a disposable 22 G needle. The
volume of bicarbonate solution added to each bottle varied from bottle to bottle, depending on initial pH.
If pH was too basic, the pH was adjusted by adding 5 N HCl. Chloroanilines (2-CA, 3-CA, and 4-CA)
and 1,2-DCB stock solutions were added for a final concentration of 13 mg/L in the liquid phase. The
chloroanilines were added as a positive control, since these compounds were degraded before in these
bottles, and re-spiked on day 60 of the experiment to keep the bottles active. Since 1,2-DCB is volatile it
was added to the bottles after sealing since it could have escaped during set-up. Other COIs, such as 3,4-
36
DCNB, 2,3-DCNB, and 2,5-DCA, were present in the bottles from the previous feedings during the
microcosm study.
From site 1B, the same procedure was carried out and the same conditions in duplicates were established.
In these bottles, a chloroaniline (2-CA, 3-CA, and 4-CA) stock solution was added for a final
concentration of 10 mg/L of each compound in the liquid phase. The chloroanilines were added as a
positive control, since these compounds were degraded before in these bottles, and re-spiked on day 60 of
the experiment to keep the bottles active. 1,2-DCB was also added to a final concentration of 10 mg/L in
the liquid phase. All bottles were sampled for GC and HPLC analysis, as described in Sections 2.2.2 and
2.2.3, for two months.
4.3.3 Results
The degradation graphs of the bottles from site 2A are shown in Figure 4.1. The chloroanilines were
rapidly degraded regardless of pH, but not other substrates (Fig. 4.1a and b). Addition of inoculum from
the University of West Florida resulted in biodegradation 2,3-DCNB and 3,4-DCNB at neutral pH
(Figure 4.1d) but not when pH was not adjusted (Figure 4.1c). The isomer 3,4-DCNB degraded at a rate
of 0.45 mg/L/day and was completely degraded after 48 days. Whereas the isomer 2,3-DCNB degraded
slightly slower and not completely but decreased in concentration from 6 mg/L to 2 mg/L after 30 days.
In the bottles from site 1B, as expected, all the chloroanilines were degraded after the feeding, and
degradation was complete after 30 days of experiment (Figure 4.2). The three CA isomers were re-spiked
on day 60 to determine if the bottles were still active. In general, the biodegradation of all three isomers
occurred at a similar rate of 0.26 mg/L/day, but 2-CA was slightly slower than the others. 1,2-DCB was
only degraded in the bottles inoculated with culture mix, regardless of pH adjustment (Figure 4.2c and
d). The average pH of the bottles in Figure 4.2c was 5, and complete degradation occurred after 48 days,
with the same rate of 0.2 mg/L/day when pH was adjusted to 7. It is possible that the microorganisms that
degrade 1,2-DCB are not affected by pH changes and can still degrade under acidic conditions. Whereas
the microorganisms that degrade DCNBs require neutral pH (Figure 4.1d).
In summary, this little experiment proved that inoculation with enriched cultures capable of DCNB or
1,2-DCB degradation enabled degradation of these compounds in microcosms that previously were
inactive against these compounds. The experiment also suggested that pH is more critical for DCNB
degradation than 1,2-DCB degradation. These results suggest that the microcosm bottles did not contain
microorganisms capable of aerobic degradation of these specific COIs. Another possibility is that the
37
microorganisms were present in the microcosms, but in such low abundance that was insufficient to
degrade the COIs.
Figure 4.1 Impact of pH and bioaugmentation on aerobic microcosms from site 2A. Average
biodegradation in the duplicate bottles observed with different treatments: A) continuing with
maintenance before combining; B) pH adjusted to neutral; C) bottles inoculated with culture mix and pH
was not adjusted; and D) bottles inoculated with culture mix and pH was adjusted to neutral. On day 60,
the chloroanilines were re-spiked. X axis represent time (days) and Y axis represent concentration of the
compound (mg/L). CA = chloroaniline, DCA = dichloroaniline, DCB = dichlorobenzene, DCNB =
dichloronitrobenzene.
38
Figure 4.2 Impact of pH and bioaugmentation on aerobic microcosms from site 1B. Average
biodegradation in the duplicate bottles observed with different treatments: A) continuing with
maintenance before combining; B) pH adjusted to neutral; C) bottles inoculated with culture mix and pH
was not adjusted; and D) bottles inoculated with culture mix and pH was adjusted to neutral. X axis
represent time (days) and Y axis represent concentration of the compound (mg/L). On day 60, the
chloroanilines were re-spiked. CA = chloroaniline, DCA = dichloroaniline, DCB = dichlorobenzene,
DCNB = dichloronitrobenzene.
Influence of pH in microcosms
4.4.1 Motivation and samples
As previously described in Chapter 3, the microcosm study was set-up to simulate the field site
conditions, where pH was not changed from what it was in the samples, as received. Since there was no
observable degradation in some of the bottles, while parallel studies done with pH adjustment showed
enhanced activity of microbes under neutral pH (Palatucci, 2017), it was decided to adjust the pH in some
of these bottles and monitor the effects on the degradation without adding an external culture and/or an
39
inoculum. Therefore, aerobic microcosms from 3 sampling locations (1A, 2A, and 2B) that showed
limited degradation were selected to determine if pH adjustment would alter biodegradation in the bottles.
Specifically, the bottles from sites 1A and 2A that were previously amended with vitamins were used for
this experiment, and the bottles from site 2B were previously designated as the active controls.
4.4.2 Methodology
For this experiment, bottles from the 3 sites were treated differently, as shown in Table D.4, and detailed
below. Sites 1A and 2A were kept in their original bottles, each in triplicates, and the site 2B bottles were
combined in a larger bottle and redistributed into 6 smaller bottles.
Aerobic microcosms from site 1A previously amended with vitamins
The triplicates from site 1A, previously amended with vitamins, had pH measurements between 5.5 and
5.8, and contained different DCNBs isomers. One of the replicate bottles had 3 mg/L of 2,3-DCNB, the
second had 6 mg/L of 2,5-DCNB, and the last one had 10 mg/L of 3,4-DCNB. These bottles had
previously biodegraded 2-CA, 3-CA, and 4-CA under natural pH. They all had been pH-adjusted to pH
6.9 by adding bicarbonate solution using a 1 mL plastic Luer-LokTM tip syringe (BD) coupled with a
disposable 22 G needle. The bottles were analyzed by HPLC for 160 days.
Aerobic microcosms from site 2A previously amended with vitamins
The triplicates from site 2A, previously amended with vitamins, had 2,3-DCNB, 3,4-DCNB, 2,5-DCA,
1,2-DCB that were not degraded during the microcosm study. Whereas 2-CA, 3-CA, 4-CA, 2,3-DCA, and
3,4-DCA were degraded in these bottles before this experiment. One of the triplicate bottles from this site
was maintained at pH 5.5. The two other replicates were pH-adjusted to pH 6.9 by adding bicarbonate
solution using a 1 mL plastic Luer-LokTM tip syringe (BD) coupled with a disposable 22 G needle. The
bottles were analyzed by GC and HPLC for 160 days.
Aerobic microcosms from site 2B previously treated as active controls
This test was conducted by Amy Li, a summer student who has worked on multiple studies in the
Edwards laboratory. The liquid phase of the triplicates from site 2B, previously known as active controls,
was removed from the original bottles using a glass pipettor and combined into an autoclaved glass bottle,
mixed, divided into six 150 mL amber glass bottles, with 35 mL of groundwater each and capped with
MininertTM caps. To recall, these bottles had degraded 2-CA, 3-CA, 4-CA, 2,3-DCA and 3,4-DCA during
the microcosm study, as described in Chapter 3. The 3 CA isomers were added as positive controls for
40
this experiment, and the DCA isomers were not added. No oxygen was added to the bottles during the
experiment, but oxygen measurements were performed in all the bottles and the oxygen content was
always between 17-19%. The following compounds remained in the bottles from the previous
experiment: 9 mg/L of 2,5-DCA, 3 mg/L of 2,3-DCNB, and 3mg/L of 3,4-DCNB.
The pH was adjusted to three different pH measurements: a) pH unadjusted at 4.6, b) pH adjusted from
4.7 to 5.8, and c) pH adjusted from 4.7 to 7. All the pH adjustments were done by adding bicarbonate
solution using a 1 mL plastic Luer-LokTM tip syringe (BD) coupled with a disposable 22 G needle. The
bottles were analyzed in HPLC for 51 days.
4.4.3 Results
The GC and HPLC results are shown in Figures D.5 to D.7. From the three sites, adjusting the pH to 7
did not lead to the degradation of the DCNBs. During the time of the experiment, no biodegradation of
DCNBs occurred in any of the bottles. The results suggest that either the microbial community in the
bottles were not capable of aerobic biodegradation of DCNBs, or the elapsed time (150 days for the first 2
experiments, and 51 days for the third experiment) was insufficient to enrich for a microbial community
that can degrade DCNBs. The bottles from site 2B, where chloroanilines were added as positive controls,
completely biodegraded, as expected (Figure D.7). This means that there were sufficient nutrients and
oxygen for biodegradation to occur, so the reason for the lack of DCNB degradation might be the lack of
microorganisms responsible for these reactions.
As presented in Section 4.3, when the enriched DCNB-degrading cultures from external laboratories were
used as inoculum in microcosms, degradation of 2,3-DCNB and 3,4-DCNB did indeed occur. Therefore,
bioaugmenting bottles with inoculum for certain more difficult to degrade compounds could help
degradation of other compounds that would use metabolites as part of their reactions.
In conclusion, the experiments described in Chapter 4 revealed that i) a deep sample collected for
exploring anaerobic processes in fact had very low biomass and limited activity; ii) aerobic
biodegradation of chloroanilines is robust while aerobic biodegradation of DCNBs and 1,2-DCB could be
observed in enrichment cultures and bioaugmented microcosms only. These results suggest uneven
distribution of biodegrading microbes at the site, highlighting the importance of further characterizing
microbial population distribution at the site (see Chapter 5). Increasing the pH to 7 can result in enhanced
rates of reactions, particularly for DCNBs. The influence of pH might be an important factor to be taken
into consideration when planning a pilot project in the field.
41
Chapter 5 Microbial community analysis
Motivation and samples
This chapter describes the process of microbial community analysis performed on samples from the site
as well as from microcosms and cultures that have been described in the previous chapters. The objectives
of these analyses are to:
1) Identify the most abundant microorganisms in groundwater and soil samples from the site;
2) Explore how the microbial community in microcosms samples behave over time when cultures
are enriched and exposed to different conditions (e.g. electron donor, vitamin, sulfate, or nitrate
amendments);
3) Compare microorganisms from enriched cultures generated by other labs to organisms found in
the microcosms and groundwater samples;
4) Identify which microorganisms are capable of biodegradation and biotransformation of COIs in
cultures and microcosms; and
5) Analyze the samples statistically and identify trends and clusters in the sample groups and among
different groups.
To achieve these objectives, samples were collected, prepared, and analyzed. A list of all the sample
names, sampling date, and additional information is shown in Table E.1 and a map showing their site
location in Figure E.1. Generally, the samples used for these analyses were:
a. Microcosm samples: Sample collected during the microcosm study started in 2015 and described
in Chapter 3. A total of 100 samples were collected and analyzed, from all the sites (1A, 1B, 2A,
and 2B, Figure C.1), under aerobic and anaerobic conditions, and focused on the bottles that were
active and biodegrading or bio-transforming some of the compounds. In most cases, the same
bottle was sampled over time, to achieve Objective 1 described above, demonstrated in Table
E.1. Even though some samples are from the same bottle, each was treated as a unique sample
during the analyses.
42
The following is a description of sample nomenclature, for example: A1_AC1_Day323a, where
the first descriptor is the site location of the sample (A1, B1, A2, or B2, Figure C.1); the second is
the treatment condition of the bottle (AC = active control, Don = electron donor, Nit = nitrate,
Sulf = sulfate, Vit = vitamins) with the number of the replicate in the series; the third descriptor is
the elapsed time of the microcosm study at the time of sample collection; and the last descriptor is
the aerobic (a) or anaerobic (an) conditions. Of note is that the site names are actually 1A, 1B,
2A, and 2B, however since it is not recommended that the sample names start with numbers, due
to programming and coding issues this might cause in RStudio, the order of letters and numbers
have been reversed.
b. Highly enriched cultures from collaborator laboratories: Samples were received from
Clemson University and the University of West Florida laboratories, as described in Section 4.3.
From Clemson University, the microbial communities of three enrichment cultures were
analyzed. These highly enrichment cultures were named to describe the compound degraded and
the condition under which degradation occurred. For example, DF2_DCBa, where DF stands for
Dr. David Freedman, principal investigator in this research at Clemson University, and the
number following is the sample number (1 to 3). The next descriptor is the compound degraded
by the culture, in this case 1,2-DCB. Lastly, the lower-case letter indicates if the culture was
grown aerobically (a) or anaerobically (an).
The microbial communities of five pure cultures from University of West Florida were also
analyzed, the details of these samples were previously described in Section 4.3. The pure cultures
names indicate many characteristics of the culture. For example, Jim_FBR_34DCNBa, where Jim
refers to Dr. Jim Spain, the principal investigator of this research at University of West Florida.
The next descriptor is the sample origin (FBR = fluidized bed bioreactor, 3050 = pure culture
degrading 3,4-DCNB, 3051 = pure culture degrading 2,3-DCNB). The third term is the
compound that was degrading, 3,4-DCNB, in this case. Lastly, the condition under which the
culture was grown (a = aerobically).
c. Soil samples: Soil samples were collected in 2015 from the Camaçari site. From the first batch of
sediment material sent to the University of Toronto to prepare the microcosm study, four soil
samples were collected, one from each site. These soil sample names explain its origin. For
example, one of these soil samples was named NO82_deep_2B, where the first descriptor is the
borehole where the sample was collected from at the site (NO82 in UN11&12, and NO83 in
NPAD, Figure C.1). The second descriptor refers to the depth of the sample (deep or shallow, as
43
shown in Figure C.2). The last descriptor is the same nomenclature for the site location as used in
the rest of this work (1A, 1B, 2A, or 2B).
d. Groundwater samples: Groundwater samples were collected from the site in 2016 and 2017.
From these samples, DNA was extracted in the on-site laboratory and DNA extracts were shipped
to the University of Toronto. These groundwater samples were collected using a low flow purge
method, in which a low flow submersible pump is placed in the monitoring well and the samples
are collected from within the well screen, which minimizes purging and improves sample quality.
This methodology is widely used in Brazil and follows the procedure published in 2010 in a
Brazilian legislation document, ABNT 15847, for groundwater sampling in monitoring wells
using different purging methods (in Portuguese, Amostragem de água subterrânea em poços de
monitoramento – métodos de purga). After the pump is introduced in the well and purging starts,
the field parameters become stable, and then sample collection can occur. The pumping flow rate
is between 0.1 to 0.5 L/min, and should not to exceed 1.0 L/min. For DNA sample collection, the
pump is connected to a plastic hose, which is then attached to a Sterivex filter 0.22 µm. The filter
will retain the microorganisms from filtering approximately 1 L of groundwater. The protocol for
DNA extraction from the Sterivex filter is described in Section 2.3.1.
The names of these DNA extracts includes the monitoring wells where they were collected from,
where DW stands for deep well, and PM stands for monitoring well (acronym for Portuguese
word). Additionally, there are two wells from the hydraulic barrier located at the site, so these
sample names include IHB (influent from hydraulic barrier) or EHB (effluent from hydraulic
barrier).
e. Groundwater samples from Cetrel: Cetrel is a company located in Camaçari and is responsible
for water supply, industrial effluent treatment, industrial waste treatment and disposal, water
reuse, and environmental monitoring of the Camaçari Industrial Complex since 1978. Cetrel’s
waste water treatment plant uses activated sludge to treat industrial effluent from multiple sites,
processing approximately 144,000 m3/day of sludge. The full process occurs in 5 steps: (a)
aerobic digestion, (b) aeration tanks, (c) landfarming, (d) settler, and (e) drying bed. The samples
for these analyses were collected from the three aeration tanks, TA01, TA02, TA04.
A total of 140 samples were sent for 16S rRNA Illumina amplicon sequencing at Genome Québec, in
2017, and the methodology is described in Section 2.4.
44
Results and discussion
5.2.1 qPCR of samples from microcosms, enriched cultures, soil, groundwater, and groundwater from Cetrel
All the samples that were sent for 16S rRNA amplicon sequencing were also analyzed by qPCR,
following the methodology described in Section 2.4. The samples were analyzed to quantify the bacteria
and archaea in all 140 samples analyzed in this study, except for 6 samples that did not have enough
volume to be analyzed. Table E.2 shows the slope, y-intercept, R2, and efficiency for all the qPCR runs
performed on these samples, and Table E.3 shows qPCR raw results.
When analyzing the results, there was a higher abundance of archaea in samples from anaerobic, electron
donor amended bottles, ranging from 1.04E+08 to 1.14E+09 copies/mL of sample. Groundwater samples
had the lowest number of archaea, ranging from 8.80E+03 to 4.06E+ 04 copies/mL, and the lowest
number of bacteria, ranging from 4.25E+05 to 4.26E+06 copies/L. The total number of bacteria was
higher than archaea in most of the samples. The highest abundance of bacteria was found in water
samples from the Cetrel aeration tanks, followed by the samples from the anaerobic, electron donor
amended bottles. These results make sense as these samples will have the highest substrate
concentrations.
The main objective of this analysis was to quantify the total amount of bacteria and archaea in all the
samples, to determine the abundance of biomass in different types of samples. As expected, enrichment
cultures and microcosm samples had more biomass when compared to environmental samples, such as
groundwater and soil samples. Samples from site 1 (NPAD) contained more bacteria and archaea than site
2 (UN11&12). To better visualize this information, the raw data is plotted in a bar chart in Figure 5.1,
ranked by Archaea and Figure E.2 shows the same graph ranked by Bacteria.
45
Figure 5.1 qPCR results (copies/mL) for microcosms, soil, groundwater, and pure culture samples. The lower graph is a continuation of the
upper graph for better visualization. The samples are ordinated from highest to lowest number of Archaea. X axis shows sample names and Y axis
show the concentration of bacteria or archaea in original sample (copies/mL).
46
5.2.2 Main operational taxonomic units (OTUs) in groundwater and soil samples from the site
A total of 32 site samples were analyzed, 28 groundwater samples and 4 soil samples that were used to set
up the microcosm study in 2015 (microcosm study #1). Other soil samples were collected and extracted
on site, but the shipment from Brazil to Canada lasted 5 days, which is longer than dry ice can last, and
DNA extracts did not survive shipment to Canada. From the analysis of these samples, three graphs were
generated: soil samples (Figure 5.2), groundwater samples (Figure 5.3), and other water samples (Figure
5.4), two samples from the hydraulic barrier and three samples from the aeration tanks from Cetrel.
Soil samples from sites 1A, 1B, and 2B contained Ktedonobacterales as the most abundant Order in this
type of sample, Figure 5.2. Environmental samples are typically diverse, unless the microorganisms are
enriched somehow in the environment. At the Camaçari site, the soil samples are from highly
contaminated areas where contamination has been present for decades, which explains why there are
dominant populations in these four soil samples.
The groundwater samples are much more diverse than the soil samples, but still enriched compared to
environmental samples that had not been exposed to contamination, shown in Figure 5.3 and collected
within the site as shown in Figure E.1. Of all the groundwater samples, the only wells sampled twice are
P073_19 and PM19, the first one collected in November 2016 and the second one in August 2017. Both
wells contain a high abundance of Betaproteobacteria. The phylogenetic tree ordinates samples according
to their microbial community similarity, which gives a better interpretation of the data. As the samples are
diverse, a phylogenetic tree is a good visualization of similar samples. Other important microorganisms
that might be able to degrade the COIs in this study are present in the groundwater samples, analysis in
Section 5.2.3. Some wells, such as DW03B, DW06, PM01, PM35, and PM45 have different
microorganisms that are highly enriched, as shown in Figure 5.3. Again, this shows high enrichment of
microorganisms at these sites due to environmental pollution over a long period of time.
Environmental samples tend to be more diverse than enriched samples, but when these samples are
exposed for long term soil and groundwater contaminations, they became enriched for specific organisms
that have the ideal metabolism to live in this type of environment.
47
Figure 5.2 Relative abundance (> 0.5%) in soil samples collected from the site. This is the resulting data from the 16S rRNA amplicon
sequencing results. The same color represents microorganisms belonging to the same taxonomy, phylogenetically assigned by MetaAmp, and
each horizontal line represents a different OTU of the same taxonomic classification. This graph shows data represented in OTU level.
48
Figure 5.3 Dendrogram and relative abundance (> 1%) in groundwater samples collected from the site. The dendrogram on the left ordinates
similar samples. As these samples are diverse, the main OTUs are plotted on the right, indicated by colors. Organisms with relative abundance lower
than 1% in the sample are not plotted. This graph shows data represented in OTU level.
49
The other water samples collected and analyzed in this study are from the hydraulic barrier (effluent and
influent) and from the aeration tanks from Cetrel, shown in Figure 5.4. Both influent and effluent water
samples contained a high abundance of the Family Comamonadaceae, at approximately 30% relative
abundance in each. The Comamonadaceae family is composed of aerobic Gram-negative
microorganisms. Diaphorobacter is also found in high abundance, around 15% relative abundance in
each, and is likely enriched due to the local contamination. In the influent sample, 47% of the sample is
composed of the Genus Burkholderia, which are obligatory aerobic, Gram-negative and rod-shaped
bacteria.
Three samples from Cetrel’s wastewater treatment plant (WWTP) were collected from the aeration tanks.
The material treated in the WWTP comes from different areas of the industrial complex and is combined
in these large capacity tanks. The genus Thauera is present in all the samples and is Gram-negative, rod-
shaped bacteria, previously found in wet soil and polluted freshwater. Aeration tank 2 contained
Phycisphaerae at 33% of the relative abundance, which is a strictly anaerobic and chemoheterotrophic
Class that had been identified in hypersaline sediments (Spring, et al., 2018).
The groundwater samples are more representative than soil samples, since the volume filtered through a
Sterivex filter is larger compared to the mass of soil used for a DNA extraction. Because of this,
groundwater samples tend to be more diverse and have more biomass since it is representing a larger
volume of the site subsurface.
50
Figure 5.4 Relative abundance (> 0.5%) in groundwater samples from Cetrel and from hydraulic barrier. This is the resulting data from the
16S rRNA amplicon sequencing results. The same color represents microorganisms belonging to the same taxonomy, phylogenetically assigned by
MetaAmp, and each horizontal line represents a different OTU of the same taxonomic classification. Names of the samples: EHB = effluent hydraulic
barrier; IHB = influent hydraulic barrier; TA = aeration tank from Cetrel. Results from 16S rRNA sequencing results. This graph shows data
represented in OTU level.
51
5.2.3 Changes in microbial community over time in microcosms samples
DNA samples were collected from the microcosms for the objective of capturing the changes in microbial
communities over time in active bottles. By doing this, it is possible to see which microorganisms were
enriched and identify community trends in the bottles.
Aerobic microcosms
Samples from active controls and vitamin-amended bottles were collected between days 70 and 333 of the
experiment. The 16S rRNA sequencing results of this experiment are presented in Figure 5.5 and Figure
5.6.
In site 1A, the Genus Pandoraea increased in relative abundance from the beginning of the experiment to
the end. This OTU is also present in one of the enrichment cultures from Clemson University, which was
reported to degrade 1,2-DCB (Quintero, 2016). Rhizomicrobium is another genus that increased in relative
abundance in site 1A vitamin-amended bottles, but not in the active control bottles. Adding vitamins to
the bottles did not drastically change the microbial communities and did not enhance or inhibit any
aerobic activity in the bottles. In site 1B, the active controls and vitamin-amended microcosms did not
show any aerobic degradation in the DCBs isomers tested. Some OTUs were enriched and contained a
high abundance of Clostridia and Ktedonobacterales, but these microorganisms are not related to the
aerobic biodegradation of dichlorobenzenes.
Similar to site 1, there was an increase in the relative abundance of Pandoraea in samples from site 2 that
degrade 1,2-DCB, specifically in site 2B. Burkholderia was the most abundant OTU in site 2, and site 2A
had a high abundance of Xanthomonadaceae, whereas site 2B had a high abundance of
Ktedonobacterales. Interestingly, the deep and shallow samples have different microbial composition
from each other, even though they were collected close to each other (Figure 5.1), which shows how
heterogeneous the soil is at this site.
52
Figure 5.5 Relative abundance (%) in aerobic microcosms samples from Site 1A and Site 1B. The same color represents microorganisms
belonging to the same taxonomy, phylogenetically assigned by MetaAmp, and each horizontal line represents a different OTU of the same taxonomic
classification. This graph shows data represented in OTU level.
53
Figure 5.6 Relative abundance (%) in aerobic microcosms samples from Site 2A and Site 2B. The same color represents microorganisms
belonging to the same taxonomy, phylogenetically assigned by MetaAmp, and each horizontal line represents a different OTU of the same taxonomic
classification. This graph shows data represented in OTU level.
54
Anaerobic microcosms
Samples from active controls, donor amended, nitrate amended, and sulfate amended bottles were
collected between days 70 and 333 of the experiment.
The microcosms from site 1A, of active controls, nitrate-amended, and sulfate-amended bottles did not
transform of any the tested compounds, as shown in Figure 5.7. The electron donor-amended bottles
transformed 2,3-DCA, 3,4-DCA, 2,5-DCA, and 1,2-DCB, and the DCAs were dechlorinated to CAs. In
these bottles, there is an increase in Dehalobacter that could be related to this anaerobic dechlorination
processes, since it is well known dechlorinators. There is also an increase in the relative abundance of
fermentative microbes in these bottles, such as Sporomusa, Anaerospora, and Thermoanaerobacteraceae,
due to the presence of lactate and ethanol in them.
The microcosms from site 1B were fed with dichlorobenzenes only, specifically 1,2-DCB, 1,3-DCB, and
1,4-DCB, as shown in Figure 5.8. None of these bottles degraded DCBs in the microcosm study. Only
after analyzing the DNA samples, it was possible to identify a dominant population of Cupriavidus in the
nitrate-amended bottles, which was reported to degrade 1,2-DCB in the cultures received from the
University of West Florida. Afterward, these bottles were re-analyzed by GC, and the concentrations
show that biotransformation of the three isomers occurred, as previously shown in Chapter 3. It is
possible that this same organism is also able to transform not only 1,2-DCB, as previously reported, but
also 1,3-DCB and 1,4-DCB. Further experiments should be done to confirm the hypothesis that this
microorganism is capable of this degradation, but the increase in abundance is a good indication. The
donor-amended bottles did degrade the DCBs tested, but the microbial community showed a significant
increase in relative abundance of Thermoanaerobacteraceae between the samples collected in days 151,
197, 241, and 323. As expected, bottles amended with electron donor have a significant effect on the
microbial community.
The microcosms from site 2A were fed with aniline, 2-CA, 3-DCA, 4-CA, 2,3-DCA, 2,5-DCA, 3,4-DCA,
2,3-DCNB, 3,4-DCNB, and 1,2-DCB, as shown in Figure 5.9. All the samples biotransformed both
isomers of DCNB and the electron donor-amended bottles also biotransformed 3,4-DCA and 1,2-DCB.
When comparing the background sample with the subsequent samples, there was an increase in
Chitinophagaceae in the active controls, sulfate-amended, and nitrate-amended bottles. Whereas the
electron donor-amended bottles are much more diverse than the background sample. The most active
microcosms, treated with electron donor, showed an increase of Leptolinea, Veillonellaceae, and
Syntrophomonas.
55
The microcosms from site 2B were fed with aniline, 2-CA, 2,3-DCA, 3,4-DCA, 2,5-DCA, 2,5-DCNB,
and 3,4-DCNB, as shown in Figure E.3. Only the electron donor-amended bottles biotransformed the
DCNBs, whereas the active controls, sulfate-amended, and nitrate-amended bottles did not. There was a
clear dominance of Ktedonobacterales in these bottles, since the beginning of the experiment, and in the
background sample. In the electron donor-amended bottles, the relative abundance of Desulfitobacterium
and Veillonellaceae slightly increased from zero to around 5% each, but not enough to be able to
hypothesize if these microorganisms can biotransform DCNBs to DCAs.
In general, it is possible to determine which populations increased over time in the microcosm samples,
according to what compounds were fed, and which were degraded and transformed. This technique can be
used as a tool to monitor the microbial population of the site and infer whether the microorganisms that
are present are capable of biodegrading and biotransforming the contaminants or, if not present, it can be
used a decision-maker for bioaugmentation at the site. In order to determine which microorganisms are
responsible for each reaction, a specific study needs to be done to isolate the microorganisms and feed
only one compound to identify biodegradation or biotransformation.
56
Figure 5.7 Relative abundance (%) of microorganisms in anaerobic microcosms samples from site 1A. Compounds tested in each site are shown
on the top of the graph in yellow box and the compound that were biotransformed are shown in the white boxes, if any. Only Bacteria is plotted in this
graph. X axis show samples names and Y axis show relative abundance (%) of each microorganism per sample. This graph shows data represented in
OTU level.
57
Figure 5.8 Relative abundance (%) of microorganisms in anaerobic microcosms samples from site 1B. Compounds tested in each site are shown
on the top of the graph in yellow box and the compound that were biotransformed are shown in the white boxes, if any. Only Bacteria is plotted in this
graph. X axis show samples names and Y axis show relative abundance (%) of each microorganism per sample. This graph shows data represented in
OTU level.
58
Figure 5.9 Relative abundance (%) of microorganisms in anaerobic microcosms samples from site 2A. Compounds tested in each site are shown
on the top of the graph in yellow box and the compound that were biotransformed are shown in the white boxes, if any. Only Bacteria is plotted in this
graph. X axis show samples names and Y axis show relative abundance (%) of each microorganism per sample. This graph shows data represented in
OTU level.
59
5.2.4 Comparison between external cultures, microcosms samples, and environmental samples
After sequencing the external enrichment cultures and obtaining the OTUs in these samples, they were
compared to all the other 140 samples sequenced in this work, to determine how abundant these
microorganisms were in the environmental samples, and where they are found throughout the site.
The eight samples from external highly enriched cultures were sequenced and the result with the 12 most
abundant OTUs are shown in Figure 5.10 and in Table E.4.
Figure 5.10 Most abundant OTUs in external laboratory highly enrichment cultures used for the
experiments in UofT. X axis are samples and Y axis are relative abundance (%). In the legend, g =
genus, f= family. The first 3 columns are the samples from Clemson University and the other samples are
from University of West Florida. CB = chlorobenzene, DCB = dichlorobenzene, NT = nitrotoluene,
DCNB = dichloronitrobenzene. FBR = fluidized bed reactor. DF = David Freedman’s samples. J = Jim
Spain’s samples. This graph shows data represented in OTU level.
In the aerobic cultures received from Clemson University (DF1 and DF2, Figure 5.10), the most
abundant OTU was Pandoraea at a 77% relative abundance in the chlorobenzene-degrading culture, and
87% in the 1,2-DCB-degrading culture. These microorganisms are Gram-negative from the family
Burkholderiaceae and were identified in crude oil contaminated sites, in soil and groundwater samples
(Tirado-Torres, et al., 2017). When compared to all the other samples in this study, this exact OTU was
found in 109 samples, and in 33 of these samples at more than 1% of relative abundance. At this relative
abundance, this OTU can be considered high in environmental samples. The higher abundant
microorganisms were mostly found in aerobic, active control microcosms, which were degrading 1,2-
DCB during the study. Therefore, the microorganism capable of degrading 1,2-DCB is present in these
bottles. Even though Pandoraea was present in an aerobic culture, when comparing it to the rest of the
60
samples it is possible to see that anaerobic microcosms also contain this OTU, especially in the active
controls. It can also be found in some groundwater samples, which means these 1,2-DCB-degrading
microorganisms are present at the site. All the samples containing Pandoraea are shown in Figure 5.11.
Rhodanobacter was found at 14% relative abundance in the aerobic chlorobenzene-degrading culture and
when compared to all the other samples in the study, it was present in only 12 samples, and always lower
than 0.1%. Even though this culture was prepared under neutral pH, this genus has been reported to be
resistant to acidic environments and was identified in groundwater samples from long-term contaminated
sites (Green, et al., 2012). Figure E.4 shows the samples that contained this OTU.
The Clemson University anaerobic culture (the third column on Figure 5.10) contained Pelosinus (56%
relative abundance), Desulfotomaculum (16% relative abundance), and Propionicicella (11% relative
abundance) which may be capable of the reduction of 4-NT to benzylamine (C7H9N), since this sample
was taken from an anaerobic 4-nitrotoluene degrading culture. Pelosinus was found in 1 groundwater
sample, 2 anaerobic electron donor-amended microcosms, and 1 aerobic active control microcosm. It is
important to remember that 4-NT was not tested in any of the microcosms at the University of Toronto, so
this activity acted as a negative control for the samples, and because of this, it is expected that these
genera are not present in many samples. The other two OTUs, Desulfotomaculum and Propionicicella,
were also compared to all the samples and the three comparisons are shown in Figure E.5.
In the cultures received from the University of West Florida, four main OTUs were dominant. The pure
cultures, J1 and J5, contained mostly Diaphorobacter, at 76% relative abundance in the aerobic 2,3-
DCNB-degrading culture, and 97% relative abundance in the aerobic 3,4-DCNB-degrading culture. When
compared to other samples, this OTU was present in 36 of the 140 samples analyzed, mostly in the
groundwater samples, as shown in Figure E.6. In some wells, this OTU was highly abundant, higher than
10% in relative abundance in 3 samples: influent and effluent of the hydraulic barrier, and in PM01.
61
Figure 5.11 Relative abundance (%) of Pandoraea (OTU10) in all the samples. X axis represents relative abundance (%) of organism in
log scale, Y axis represents the sample name where the organism was found.
62
Besides Diaphorobacter, an OTU from the family Alcaligenaceae was dominant in two samples from the
FBR, one fed with 2,3-DCNB and the other with 3,4-DCNB, J3 and J7, respectively. The relative
abundance in J3 was 48% and in J7 was 43%, and in both cases, a second OTU was also highly abundant:
Rhodococcus, which was only found in one other sample besides the external culture, as shown in Figure
E.7. Alcaligenaceae was present in 80 samples, and mostly found in active control microcosms, under
both aerobic and anaerobic conditions. To identify which microorganism this OTU was most related to,
the 16S rRNA sequence was searched using the NCBI (National Center for Biotechnology Information)
basic local alignment search tool (BLAST), which uses an algorithm that compares biological sequence
information. BLAST results showed a similarity of 100% with Achromobacter and Bordetella, both
obligate aerobes. Since this organism is present in high abundance in both DCNB-degrading cultures, it is
possible that this microorganism contributes to the biodegradation pathway of 2,3- and 3,4-DCNB. The
samples that contain this microorganism are presented in Figure E.8.
The last sample analyzed from the University West Florida was J8, a sample prepared with sand from the
FBR and that was degrading 1,2-DCB aerobically in the bottles prepared in the Edwards lab. In this
sample, a relative abundance of 77% of the microbial community was Cupriavidus, which was found in
92 samples, mostly in groundwater from PM01 and DW04, and in anaerobic microcosms amended with
nitrate, as shown in Figure E.9. These microcosms degraded 1,2-DCB, 1,3-DCB, and 1,4-DCB, and it is
possible that this organism is using the oxygen from the nitrate for aerobic respiration, since these bottles
are anaerobically maintained. This genus has been reported to biodegrade 2-chloro-4-nitrophenol in
temperatures varying from 20-40°C and pH values from 5 to 10 (Min, et al., 2018), which means it can
survive in the acidic sediments of the Camaçari site.
After comparing the highly abundant microorganisms from external enrichment cultures, most of these
microorganisms are present in site samples, and can be enriched when high concentrations of COIs are
present, either in the field as seen in the groundwater and soil samples, or in the laboratory as seen in
microcosms samples. This means there is a potential for bioaugmentation at the site, and if the proper
conditions are provided for the microorganisms to be enriched, they can certainly grow and biodegrade or
biotransform the COIs.
5.2.5 NMDS analyses in multiple groups of samples
The statistical analysis used for this study is called non-metric multidimensional scaling (NMDS) and the
objective of this analysis was to represent the samples in a low-dimensional space according to the
similarity.
63
NMDS is an analysis that identifies gradients and relationships between samples based on their similarity,
presented by sample distance on the generated graph (Ramette, 2007). The NMDS algorithm ranks
distances between objects and uses these ranks to map the objects in a non-linear and two-dimensional
way. As this method works with multidimensional data, it is important to define how many dimensions,
also known as K, which will be used for the analysis, and this number of K will define the stress in this
analysis, which can range from 0 to 1. A stress level higher than 0.3 indicates arbitrary ordination, higher
than 0.2 is suspect, equal to or below 0.1 is considered fair and might contain some distances misleading
the results, and equal to or less than 0.5 shows a good fit of the samples in the NMDS (Buttigieg and
Ramette, 2014).
In this study, NMDS was performed on all of the samples combined, and then for different groups, as
described later in this section. The software RStudio version 3.4.3 was used to perform these analyses and
different packages were used, such as Phyloseq and Vegan. The script used to process this data can be
found in Appendix F. The inputs used in this software to run these analyses were: a) an OTU table with
the respective taxonomy for the samples, b) sequencing results for all the samples with the number of
reads for each OTU, and c) a metadata table (electronic version available in Syntrophy folder) that
contains field and laboratory measurements, either quantitative (pH, temperature, amendments, etc.) or
qualitative (contaminant degraded, sample location in the site, treatment, etc.).
When plotting different types of samples in the same NMDS, is it expected that the stress level is high
when comparing the stress to a NMDS plot with similar samples. In this case, stress level was 0.18 when
plotting only two dimensions. Figure 5.12 shows all the samples combined in one NMDS plot, including
highly enrichment cultures samples from external laboratories, groundwater samples from the site,
groundwater from Cetrel samples, microcosms samples, and soil samples.
64
Figure 5.12 NMDS plots for all the samples. Enrichment culture (pure culture) samples, groundwater
samples, groundwater from Cetrel samples, microcosms samples, and soil samples in two different
NMDSs: A) different types of samples colored differently and clustering together according to their type;
B) samples colored by their pH when measured either in the field or during experiments (soil samples in
gray representing no pH measurement). Stress value 0.18, number of dimensions (k): 2.
The NMDS of aerobic and anaerobic microcosms in the same plot, the stress level was 0.17 when they
were combined. Aerobic microcosms NMDS showed a stress level of 0.07 and anaerobic microcosm, a
stress level of 0.2 (Figure 5.13). In this case, depth where the samples were collected from, pH, and
number of bacteria from qPCR were the three parameters that most drove the samples cluster.
65
Figure 5.13 NMDS plots for all microcosms, aerobic microcosms, and anaerobic microcosms. A)
NMDS plot for aerobic and anaerobic microcosms combined, colored by condition, shaped by site, stress
0.17, k=2. B) NMDS plot for aerobic microcosms showing the most significant metadata plotted in gray
arrows, stress 0.07, k=2. C) NMDS plot for anaerobic microcosms showing the most significant metadata
plotted in gray arrows, stress 0.2, k=2. Both graphs only show the significant metadata for these sets of
samples.
Figure 5.14 shows two NMDS plots for the aerobic microcosms, where plot A show the samples colored
by the degradation observed in each of them and plot B showing the most significant OTUs for these
samples. Figure 5.15 shows the same type of graph for the anaerobic microcosms. It is important to
mention that the OTUs that are plotted in these figures are not necessarily responsible for the degradation
or transformation, but they are somehow driving the sample clustering. In Figure 5.14B, for instance,
Alcaligenaceae is the most significant OTU for the samples degrading CAs and DCAs in site 2A. This
OTU is not necessarily related to the degradation, but as it is enriched in these samples, it may be
somehow involved in these reactions. In other words, this is a good initial analysis when looking for
OTUs that might be capable of degradation of COIs, but more specific experiments need to be conducted
in order to confirm this hypothesis.
66
Figure 5.14 NMDS plots for aerobic microcosms and significant OTUs. A) NMDS plot for aerobic
microcosms with samples colored by degradation observed in each sample. The color legend shows all
the compounds being degraded in these bottles, and the shapes mean the treatment each bottle received.
B) NMDS plot for the same samples and plotting the most significant OTUs, with p value 0.001, and r2 >
0.7. Stress level 0.07, k=2 for both plots.
67
Figure 5.15 NMDS plots for anaerobic microcosms and significant OTUs. A) NMDS plot for
anaerobic microcosms with samples colored by transformation observed in each sample. The color legend
shows all the compounds being transformed in these bottles, and the shapes mean the treatment each
bottle received. B) NMDS plot for the same samples and plotting the most significant OTUs, with p value
0.001, and r2 > 0.4. Stress level 0.13, k=2 for both plots.
Similarly, the four sites were analyzed separately, with aerobic and anaerobic microcosms from each of
them in the figures. Figure 5.16 shows the NMDS plots for site 1A, stress level 0.07, showing the
samples clustering by degradation and transformation, and the main OTU in these samples: Methanocella,
Acetobacteraceae, Deinococci, Bradyrhizobium, and Burkholderia.
68
Figure 5.16 NMDS plots for aerobic and anaerobic microcosms from Site 1A and significant OTUs.
A) NMDS plot for all microcosms from site 1A with samples colored by aerobic degradation (in cold
colors) and anaerobic transformation (in warm colors) observed in each sample. The color legend shows
all the compounds being degraded or transformed in these bottles, and the shapes mean the treatment each
bottle received. In the legend, A= aerobic and AN = anaerobic, followed by the compounds being
degraded. B) NMDS plot for the same samples and plotting the most significant OTUs, with p value
0.001, and r2 > 0.75. Stress level 0.07, k=2 for both plots.
NMDS plot for site 1B, that only degraded 1,2-DCB, shows Miscellaneous-Crenarchaeotic-Group
(Archaea), Candidatus-Koribacter, and Rhizomicrobium as the main OTUs for this site, as shown in
Figure 5.17. Even though Cupriavidus is highly abundant in the anaerobic microcosms from site 1B
(around 35% of relative abundance), the aerobic microcosms are also plotted in the NMDS and can
69
influence the main OTUs to be plotted. When looking at Figure 5.5, Candidatus-Koribacter is highly
abundant (around 30%) in the aerobic microcosms from site 1B.
Figure 5.17 NMDS plots for aerobic and anaerobic microcosms from Site 1B and significant OTUs.
A) NMDS plot for all microcosms from site 1B with samples colored by aerobic degradation (in cold
colors) and anaerobic transformation (in warm colors) observed in each sample. The color legend shows
all the compounds being degraded or transformed in these bottles, and the shapes mean the treatment each
bottle received. In the legend, AN = anaerobic, followed by the compound being degraded. B) NMDS
plot for the same samples and plotting the most significant OTUs, with p value 0.001, and r2 > 0.75.
Stress level 0.08, k=2 for both plots.
Degradation and transformation from site 2A, as well as the main OTUs are shown in Figure 5.18. In this
case, the main OTUs presented are Burkholderia, Cupriavidus, and Leptolinea, Thermincola.
70
Figure 5.18 NMDS plots for aerobic and anaerobic microcosms from Site 2A and significant OTUs.
A) NMDS plot for all microcosms from site 2A with samples colored by aerobic degradation (in cold
colors) and anaerobic transformation (in warm colors) observed in each sample. The color legend shows
all the compounds being degraded or transformed in these bottles, and the shapes mean the treatment each
bottle received. In the legend, AN = anaerobic, followed by the compound being degraded. B) NMDS
plot for the same samples and plotting the most significant OTUs, with p value 0.001, and r2 > 0.6. Stress
level 0.1, k=2 for both plots.
In samples from site 2B, the main OTUs were Alcaligenaceae, Ktedonobacterales, and
Xanthomonadaceae, which are shown in Figure 5.19.
71
Figure 5.19 NMDS plots for aerobic and anaerobic microcosms from Site 2B and significant OTUs.
A) NMDS plot for all microcosms from site 2B with samples colored by aerobic degradation (in cold
colors) and anaerobic transformation (in warm colors) observed in each sample. The color legend shows
all the compounds being degraded or transformed in these bottles, and the shapes mean the treatment each
bottle received. In the legend, AN = anaerobic, followed by the compound being degraded. B) NMDS
plot for the same samples and plotting the most significant OTUs, with p value 0.001, and r2 > 0.75.
Stress level 0.09, k=2 for both plots.
These molecular techniques are great tools to initially assess the samples in a large study like this, since it
provides an understanding of the big picture of the microbial communities of the site and which
conditions impact the microbial community in situ. It also suggests the next experiments to be performed
in order to narrow down the possibilities and understand which microorganisms are capable of the
biodegradation and biotransformation, if they are at the site, and how they can be enriched.
72
Chapter 6 Conclusions and future work
Conclusions
As previously presented in Chapter 1, this research’s objectives aimed to:
1) Interpret degradation and transformation data from microcosms studies;
2) Assess impact of pH on degradation in different samples;
3) Perform a comprehensive microbial community analysis in multiple groups of samples;
4) Compile data and interpret results to recommend best course of action for remediation at the site.
6.1.1 Aerobic and anaerobic reactions observed during microcosms study
The table below shows all the reactions observed during the initial microcosm study and the different
bottles were the reactions occurred. These results fill some gaps in the literature review, such as anaerobic
transformation of dichloronitrobenzenes and the analysis of a mixture of these compounds. To date,
studies have not been undertaken that involve mixing these compounds and assessing their inhibitory
effects to each other.
Table 6.1 Summary of aerobic degradation and anaerobic biotransformation observed in the
microcosm study #1
6.1.2 Impact of pH in different degradation laboratory tests
Different laboratory tests were conducted during this work with the objective of assessing the impact of
pH in aerobic and anaerobic reactions in microcosms. For some aerobic processes, neutral pH seems to
determine if the reactions will occur, as shown in Figure 4.1, or if they will be slightly accelerated, as
1A 1B 2A 2B 1A 1B 2A 2B
Aniline nt nt nt AC/ Vit nt nt - -
2-CA AC/ Vit nt AC/ Vit AC/ Vit - nt - -
3-CA nt nt AC/ Vit AC/ Vit nt nt - nt
4-CA nt nt AC/ Vit AC/ Vit nt nt - nt
2,3-DCA AC/ Vit nt AC/ Vit AC/ Vit Don nt Sulf -
2,5-DCA* AC/ Vit nt AC/ Vit AC/ Vit Don nt - -
3,4-DCA AC/ Vit nt AC/ Vit AC/ Vit Don nt Don, Sulf -
2,3-DCNB - nt - - nt nt nt nt
2,5-DCNB - nt - - nt nt AC, Don, Sulf, Nit Don
3,4-DCNB - nt - - nt nt AC, Don, Sulf, Nit Don
1,2-DCB AC/Vit - AC/ Vit AC/ Vit Don Nit Don -
1,3-DCB - - nt nt - Nit nt nt
1,4-DCB - - nt nt - Nit nt nt
AC = active control / Vit = vitamins/ Don = donor amended / Sulf = sulfate amended / Nit = nitrate amended / nt = not tested in this set
* = slow or not complete degradation
Dichloro-
benzene
ANAEROBICGroup Contaminant
AEROBIC
Aniline and
chloroanilines
Dichloro-
nitrobenzene
73
shown in Figure 4.2. For anaerobic samples, all the reactions observed were under acidic conditions and
when pH was adjusted to neutral, it did not seem to change the reactions in these bottles. With that, it is
possible to infer that environmental conditions can influence in degradation rate if the microorganisms
responsible for these reactions are present in the sample and if they are abundant enough to perform these
reactions. Some microorganisms have an optimum pH to live in and some have the capacity to adapt to a
broader range of pH.
6.1.3 Microbial community analysis
Different analyses were performed using amplicon sequencing for different types of samples: microcosms
samples, soil samples, groundwater samples, and pure cultures samples. These results were analyzed by
the NMDS statistical method to understand what are the major factors that influence the microbial
community in these samples. The treatment each bottle received, and the reactions observed in them are
the two factors that most determine the microbial abundance in environmental samples for this study.
The microbial community in microcosms samples change over time according to the reactions observed
in them and tend to enrich for the OTUs that might be responsible for the degradation reactions observed.
In samples that did not show degradation, and have more than one DNA sample, it is possible to see the
reproducibility of the method, since the relative abundance of the main organisms almost does not change
(Figure 5.5, site 1B).
When looking at environmental samples (groundwater and soil), it is possible to see that soil samples
represent a smaller (more discrete) portion of the subsurface, whereas groundwater represents a larger
sampling volume. This can be seen in the bar charts (Figures 5.2 and 5.3), where the soil is highly
enriched, and groundwater is more diverse.
When comparing the highly enriched cultures samples grown repeatedly on a single substrate to
environmental and microcosms samples, it was possible to see that the main organisms known to degrade
some compounds are present in high abundance in groundwater samples from the site (Figure E.5) and
enriched in microcosms (Figure 5.11).
6.1.4 Potential microorganisms responsible for biodegrading COIs in this study
When combining the amplicon sequencing results and analyzing the degradation and transformation
reactions in the samples, it is possible to identify microorganisms that might be responsible, or at least
very involved somehow, in these processes. In aerobic microcosms, Burkholderia was the most abundant
74
organism overall, Betaproteobacteria was also dominant in site 1A, Candidatus-Koribacter in site 1B,
Xanthomonadaceae in site 2A, and Ktedonobacterales in site 2B. In anaerobic microcosms, the most
abundant Bacteria were: Ktedonobacterales in site 1A, Cupriavidus in active bottles from 1B,
Burkholderia in site 2A, and Ktedonobacterales in site 2B.
From these results, it is possible to categorize the microbial assignments related to biodegradation from
microcosms and cultures in three types: 1) indisputable, 2) probable, and 3) potential. In 1) indisputable
degraders, it is possible to conclude that Pandoraea degrades 1,2-DCB and CB aerobically (Figure 5.10
and Figure 5.11), Cupriavidus degrades 1,2-DCB (Figure 5.10 and 5.8), and Diaphorobacter degrades
2,3- and 3,4-DCNB (Figure 5.10 and E.5). The genus Pandoraea belongs to Burkholderiaceae family
and class betaproteobacteria. Pandoraea sp. has been reported to biodegrade lindane (Okeke, et al., 2002),
phenol (Amer, 2008), and also lignin (Kumar, et al., 2018).
Different studies have reported Cupriavidus as responsible microorganisms for aerobic degradation of the
pesticide 2,4-dichlorophenoxyacetic acid. Cupriavidus campinensis BJ71 was isolated from contaminated
soil samples from Beijing (Han, et al., 2015), Cupriavidus sp. CY-1 has demonstrated to degrade the
same compound in samples from Japan (Chang, et al., 2015), and Cupriavidus gilardii T-1 has been
reported to have optimal conditions of pH 7 – 9, and temperature between 37°C and 42°C to degrade the
same compound (Wu, et al., 2017). Even though all the studies have demonstrated aerobic activity from
Cupriavidus, this genus was found in high abundance in samples collected from an anaerobic microcosm
fed with nitrate (Figure C.3 for the degradation plot and Figure 5.8 for the bar charts with amplicon
sequencing data). This might suggest that Cupriavidus is not a strict aerobe and can perhaps use nitrate as
an alternative electron acceptor to oxygen to degrade dichlorobenzenes.
The genus Diaphorobacter belongs to the family of Comamonadaceae and class of betaproteobacteria.
This genus has been reported to degrade 3-nitrotoluene aerobically, after being isolated from industrial
wastewater from a facility treatment plant in India (Singh and Ramanathan, 2013).
In 2) probable degraders, it is possible that Dehalobacter is dechlorinating DCAs anaerobically (Figure
5.7) and Burkholderia and Betaproteobacteria are involved in aerobic degradation of CAs and DCAs
(Figures 5.5 and 5.6). As there were many different numbers of OTUs for these organisms in the
sequencing data from this work, it is important to match these OTU sequences to those in well-known
databases to try to identify more specifically the roles of the microorganism in the bottles. Further work
to characterize and sequence the dominant strains is required.
75
In 3) potential degraders, it is possible to say that Alcaligenaceae (OTU11) can be involved in the aerobic
degradation of 2,3- and 3,4-DCNB (Figure 5.10), degradation of CAs and DCAs (Figure 5.14B) and is
highly present (over 10%) in some anaerobic active control microcosms transforming DCNBs (Figure
E.7). It is possible to say that this microorganism can be involved in reactions degrading DCAs and
DCNBs and bio transforming anaerobically DCNBs.
The NMDS graphs also show different OTUs that are significant to certain groups of samples that might
also be involved in the degradation and transformation of compounds. To better assess and confirm these
hypotheses, it is important to further isolate specific bacteria and identify which OTUs can degrade these
compounds. Moreover, it is important to understand specific conditions where these organisms can live
and perform their reactions properly.
Recommendations and future work
Based on the outcomes of this study, a number of recommendations should be considered, including:
a) Continue to monitor and re-amend microcosms that are showing degradation and transformation
for further DNA analysis and assess new changes in microbial community. Active bottles can
also be used for further experiment using different techniques, such as compound specific isotope
analysis;
b) From active microcosms, try to isolate specific microorganisms by making transfers and feeding
them specific compounds to enrich for relevant microbial population. Perform further DNA
analysis and amplicon sequencing to identify this organism for each compound analyzed;
c) Compare significant OTUs present in pure cultures and microcosms to new groundwater and soil
samples from the site. This will allow a better understanding of the microbial distribution in the
site and potential hot spots where an active community might be present at the site;
d) Sequence and analyze more groundwater and soil samples from the site to monitor microbial
community abundance and composition, aiming to identify zones where natural attenuation is
occurring or can be enhanced. It can also help identifying areas that need more intervention to
mitigate the risk of spreading the contamination even more in the site. All this information can be
integrated into the conceptual site model that is being developed for this study site.
Analyzing the microbial community at a contaminated site can be a powerful tool to identify hot spots of
biodegradation and biotransformation of compounds of interest. It can also guide the decision making in a
case of a pilot project, regarding which conditions should be changed or maintained in the field to
stimulate these reactions to occur. When combining the results from this works with historical data from
76
the site, field parameters, and other tools being used in this site, it can lead to an optimized remediation
strategy.
From this study, it is possible to conclude that the site has a potential for biostimulation, where specific
conditions can be altered in the field to stimulate the growth and enrichment of certain organisms.
77
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83
Appendix A. Supplementary information for Chapter 1
Table A.1 Concentrations (mg/kg) of specific COIs in soil samples from the site. Values taken from the Real Time Investigation Technical
Memorandum, conducted by CH2MHill in 2015.
Group Compound
Soil Concentration (mg/kg - dry weight)
Site 1 (NPAD) Site 2 (UN11&12) CONAMA
420 a USEPA b
Maximum Average Low Maximu
m Average Low Brazil U.S.
Aniline and
chloroanilines
Aniline 16 11.6 7.09 2.1 2.1 2.1 410
m-Chloroaniline (3-CA) 117165 15825 0.66 4478.9 1126.6 8.4
o-Chloroaniline (2-CA) 87 28.3 1.01 4 2.5 0.9
p-Chloroaniline (4-CA) 17892 7142 4.28 ND ND ND 12
2,3-Dichloroaniline (2,3-DCA) 14897 1663 0.44 633.2 129.4 0.4
3,4-Dichloroaniline (3,4-DCA) 1812 270.9 0.93 406.9 77.4 1
2,5-Dichloroaniline (2,5-DCA) 1315 304.7 2.58 37.3 23.3 9.5
Chloro-
benzenes
o-Dichlorobenzene (1,2-DCB) 1847 111.3 0.01 2053.4 67.6 0 400 930
p-Dichlorobenzene (1,4-DCB) 1908 130.6 0.02 464.8 30.8 0 150 11
m-Dichlorobenzene (1,3-DCB) 315 33.2 0.03 261.1 28.1 0 NA NA
Chloronitro-
benzene
3,4-Dichloronitrobenzene
(3,4-DCNB) 3537 679 19.48 7573.9 951.5 1.5
2,3-Dichloronitrobenzene
(2,3-DCNB) 47 13.2 0.69 3392.5 652.6 0.4
2,5-Dichloronitrobenzene
(2,5-DCNB) 97 41.6 2.23 41.5 41.5 41.5
a Environmental agency from Brazil, CONAMA 420 (2009). Maximum acceptable values for soil in industrial area.
b Environmental agency from the U.S. November 2017
84
Table A.2 Concentrations (mg/L) of specific COIs in groundwater samples from the site. Values taken from the Real Time Investigation
Technical Memorandum, conducted by CH2MHill in 2015.
Group Compound
Groundwater Concentration (mg/L)
Site 1 (NPAD) Site 2 (UN11&12) CONAMA 420 a USEPA
b
Maximum Average Low Maximum Average Low Brazil U.S.
Aniline and
chloroanilines
Aniline 1.874 1.204 0.316 25.657 5.69 0.127 0.013
m-Chloroaniline (3-CA) 13.077 5.626 1.232 - - -
o-Chloroaniline (2-CA) 27.522 9.689 2.638 40.638 8.485 0.094
p-Chloroaniline (4-CA) 4.383 1.526 0.474 17.207 5.546 0.116 0.00036
2,3-Dichloroaniline (2,3-DCA) 33.919 14.409 1.371 100.571 19.187 0.124
3,4-Dichloroaniline (3,4-DCA) 60.419 16.626 0.081 122.762 42.923 0.055
2,5-Dichloroaniline (2,5-DCA) 8.188 3.568 0.213 3.252 1.454 0.559
Chloro-
benzenes
o-Dichlorobenzene (1,2-DCB) 5.556 2.025 0.057 3.943 1.704 0.053 1
p-Dichlorobenzene (1,4-DCB) 4.177 1.068 0.042 1.517 0.371 0.041 0.3
m-Dichlorobenzene (1,3-DCB) 1.239 0.495 0.025 0.326 0.141 0.029
Chloronitro-
benzenes
3,4-Dichloronitrobenzene
(3,4-DCNB) 0.847 0.847 0.847 25.879 11.766 0.493
2,3-Dichloronitrobenzene
(2,3-DCNB) ND ND ND 3.195 1.318 0.113
2,5-Dichloronitrobenzene
(2,5-DCNB) ND ND ND 0.144 0.144 0.144 1 0.03
a Environmental agency from Brazil, CONAMA 420 (2009). Maximum acceptable values for soil in industrial area.
b Environmental agency from the U.S. Resident soil to groundwater RSL November 2017
ND = not detected
85
Table A.3 Physical characteristics of COIs. Information obtained from PubChem Compound Database and National Center for Biotechnology
Information.
Group Compound Molecular
formula
CAS
number
Molecular
weight
(g/mol)
Phase (at
room
temperature)
Color / Odor
Boiling
point
(°C)
Melting
point
(°C)
Solubility
in water
(mg/L) /
at X °C
Anil
ine
and c
hlo
roan
ilin
es
Aniline C6H7N or
C6H5NH2 62-53-3 93.129 liquid
colorless to brown when
oxidized. Fish odor 184 -6
36000 /
25
2-CA C6H6ClN or
(C6H4) Cl(NH2) 95-51-2 127.571 liquid
Colorless to amber. Sweet
odor 209 -2 8165 / 25
3-CA C6H6ClN or
(C6H4) Cl(NH2) 108-42-9 127.571 liquid
Colorless to amber. Sweet
odor 230 -10 5400 / 20
4-CA C6H6ClN or
(C6H4) Cl(NH2) 106-47-8 127.571 solid
White or pale yellow.
Sweet odor 232 72 3900 / 25
2,3-DCA C6H5Cl2N or
(C6H3) Cl2(NH2) 27134-27-6 162.013 solid
Ambar to brown crystalline
solid / crystals. 252 24 none
2,5-DCA C6H5Cl2N or
(C6H3) Cl2(NH2) 95-82-9 162.013 solid Brown crystalline solid. 251 50 none
3,4-DCA C6H5Cl2N or
(C6H3) Cl2(NH2) 95-76-1 162.013 solid
Light brown crystals with
characteristic odor. 272 72 none
Ch
loro
ben
zen
es
1,2-DCB C6H4Cl2 95-50-1 146.998 liquid Colorless to pale yellow.
Pleasant aromatic odor 180 -17 156 / 25
1,3-DCB C6H4Cl2 541-73-1 146.998 liquid Colorless 173 -24.8 125 / 25
1,4-DCB C6H4Cl2 106-46-7 146.998 solid
Colorless or white
crystalline. Mothball-like
odor
174 53 79 / 25
Chlo
ron
itro
-
ben
zenes
2,3-DCNB C6H3Cl2NO2 3209-22-1 191.995 solid Colorless to yellow. 257 61 62.4 / 20
2,5-DCNB C6H3Cl2NO2 89-61-2 191.995 solid Colorless to light beige 255 41 121 / 20
3,4-DCNB C6H3Cl2NO2 99-54-7 191.995 solid Yellow flakes 261 55 92.1 / 20
86
Table A.4 Aerobic degradation of aniline and chloroanilines reported in the literature.
Substrate Organism reported to
degrade / transform Comments Reference
Aniline <16mM
Pseudomonas multivorans
strain An1
Isolated from forest soil. Optimal pH was 6.5. Concentrations
higher than 16mM of aniline were toxic for the organism. (Helm and Reber, 1979)
Aniline
Rhodococcus erythropolis
AN-13
Aniline concentrations from 0.65 to 2.6 mg/L. Aniline was
metabolized through catechol. (Aoki, et al., 1983)
Aniline Pseudomonas sp. B13
Chloroanilines were used to genetically select different organisms
that would degrade aniline. (Latorre, et al., 1984)
Aniline, 2-CA, 3-
CA, 4-CA, 4-
fluoroaniline, 4-
bromoaniline
Moraxella sp. strain G 4-CA generation time was 6h. This organism did not degrade 3,4-
DCA. (Zeyer, et al., 1985)
Aniline as low as
50nM
Pseudomonas sp. strain K1 Generation time in 1mM of aniline was 2h, and in 8mM of aniline
was 2.2 h. (Konopka, et al., 1989)
Aniline, 3-CA, 4-
CA, 2-CA
Pseudomonas acidovorans
CA26, CA28, CA37, CA45
CA26 and CA45 showed low rates of 2-CA.
CA28 showed generation time of 3 hours and complete
mineralization at 2.25mmol aniline g-1 of biomass/hour, and 7.7
hours for 3-CA with rate of 1.63mmol 3-CA g-1 of biomass/hour.
(Loidl, et al., 1990)
2-CA, 3-CA, 4-
CA, 3,4-DCA
(mixed and
separated)
Pseudomonas acidovorans
strain BN3.1
Pseudomonas ruhlandii
strain FRB2
Pseudomonas cepacia strain
JH230
Pseudomonas aeruginosa
strain RHO1
Organisms from soil slurry. Both studies analyze the mixture of
organisms in a mixture of contaminants.
(Brunsbach and
Reineke, 1993;
Brunsbach and Reineke,
1995)
87
Substrate Organism reported to
degrade / transform Comments Reference
3-CA
Comamonas testosterone
strain I2gfp
Isolated from activate sludge. During mineralization, a yellow
intermediate was generated because of the meta-cleavage of
chlorocatechol.
(Boon, et al., 2000)
Aniline up to
53.8mM
Delftia sp. AN3
Uses aniline or acetanilide as sole carbon source.
Aniline degradation rate 5000 mg/L, at 30°C and pH7. First study
to report Delftia as responsible for aniline degradation.
(Liu, et al., 2002)
3,4-DCA, 3-CA
Pseudomonas sp.
Acidovorax sp.
Delftia sp.
Achromobacter sp.
Comamonas sp.
Organisms isolated from soil samples, testes in both 3-CA and
3,4-DCA. (Dejonghe, et al., 2002)
Aniline up to
34.4mM
Delftia tsuruhatensis 14S
Organism isolated from activated sludge of sewage disposal
plants. Aniline degradation at concentrations up to 3200 mg/L in
less than 20 days.
(Sheludchenko, et al.,
2005)
4-CA (main
compound tested),
but also 2-CA, 3-
CA, and aniline
Acinetobacter baumannii
CA2
Pseudomonas putida CA16
Klebsiella sp. CA17
Degradation occurred through ortho-cleavage pathway. 4CA
concentrations from 0.2 – 1.2mM. Also grew on 2-CA, 3-CA, and
aniline.
(Vangnai and
Petchkroh, 2007)
88
Substrate Organism reported to
degrade / transform Comments Reference
Aniline Rhodococcus
Aniline concentration from 3 to 4mM, at 30°C, with optimal pH
6.4. Concentrations higher than 10mM of aniline were toxic for
the organism.
(Obinna, et al., 2008)
Aniline Delftia sp. XYJ6
Best conditions for growth: pH 7 and 30°C. Aniline initial
concentration of 2000 mg/L removed after 22h.
Degradation pathway from aniline being converted to catechol and
then biodegraded to smaller products.
(Xiao, et al., 2009)
2-CA, 3-CA, 4-CA
(Concentrations
from 100 – 400
mg/L) and some
DCAs
Delftia tsuruhatensis H1
The presence of aniline inhibited the degradation of
chloroanilines. Addition of yeast extract, citrate or succinate
appeared to accelerate CA degradation. Some dichloroanilines
were also degraded by the organism (2,3-, 2,4-, and 3,4-DCA)
possibly through ortho-cleavage pathway.
(Zhang, et al., 2010)
3,4-DCA,
dichloroanilines, 4-
CA
Acinetobacter baylyi strain
GFJ2
Organism isolated from soil contaminated with herbicides. Aniline
present as first intermediate when degrading 4-CA and 4-
chlorocatechol. 4-CA was present as the first intermediate in 3,4-
DCA degradation.
(Hongsawat and
Vangnai, 2011)
89
Substrate Organism reported to
degrade / transform Comments Reference
Propanil and its
main product: 3,4-
DCA
Xanthomonas sp.
Acinetobacter calcoaceticus
Rhodococcus sp.
Pseudomonas sp.
Kocuria
Study conducted in a biofilm reactor. Complete removal of
contaminants at propanil loading rates up to 24.9 mg/L/h. When
loading rate was higher than that, removal efficiency decayed.
First study to report Kocuria as 3,4-DCA degrader.
(Herrera-Gonzalez, et
al., 2013)
Aniline, 3-CA
Comamonas testosterone
strain A
Delftia acidovorans strain B
(from WWTP)
Delftia acidovorans strain C
(from a linuron treated soil)
When aniline was present, degradation of 3-CA was completed
within 14 to 24 hours, faster than when 3-CA was the only carbon
source. Initial concentrations of 3-CA between 100-200 mg/L.
D. acidovorans B was not able to use 3-CA as sole carbon source.
(Shah, 2014)
Aniline, 4-CA
Pseudomonas stutzeri
Comamonas testosterone
Pseudomonas putida
Stenotrophomonas
maltophilia
Incomplete dichlorination of 4-CA and accumulation of 4-
chlorocatechol, which was further degraded via ortho-cleavage
pathway.
Interspecies interactions responsible for both degradations.
(Kalam, 2016)
90
Table A.5 Anaerobic transformation of aniline and chloroanilines reported in the literature
Substrate Organism reported to
degrade / transform Comments Reference
Aniline and
dihydroxybenzenes
Desulfobacterium anilini
Ani1 (sulfate reducing
organism)
Isolated from marine sediment. Degraded aniline completely to
CO2 and NH3. Grew on sulfide-reduced mineral medium. The
identified intermediate was 4-ainobenzoate.
(Schnell, et al., 1989;
Schnell and Schink,
1991)
Aniline
Strain HY99 (96% overall
similarity to Delftia
acidovorans)
Strain HY99 was similar to Delftia acidovorans that degraded
aniline aerobically, but HY99 degraded also anaerobically with
nitrate reduction. Aniline concentration was 1000 µM: aerobically
it degraded in 30 hours and anaerobically, in more than 7 days.
(Kahng, et al., 2000)
3,4-DCA Rhodococcus sp. strain 2
Degradation of 3,4-DCA under nitrate reducing conditions.
Formation of 1,2-DCB as one intermediate in this reaction.
Cultures incubated at 28°C, with 3,4-DCA concentration of
0.6mM.
(Travkin, et al., 2002)
2,3-DCA Dehalococcoides mccartyi
strain CBDB1
2,3-DCA → 3-CA growth yield of 5.7 - 8.7 × 1013 cells/mol
halogen released. (Cooper, et al., 2015)
Aniline
Ignavibacterium album
Acidovorax spp.
Anaerolineaceae
Initial concentration of 100 µM in phase I and 1500 µM in phase
II. Aniline loss was observed in both nitrate and sulfate amended
microcosms.
(Sun, et al., 2015)
91
Table A.6 Aerobic degradation of chlorobenzenes reported in the literature.
Substrate Organism reported to
degrade / transform Comment Reference
1,2-DCB Pseudomonas sp. JS100 Organism isolated from activated sludge. Minimal doubling time of
growth was 5.5h. Nitrate was the preferred nitrogen source. (Haigler, et al., 1987)
1,4-DCB Pseudomonas sp. JS6
Organism isolated from activated sludge. Concentrations of 1,4-DCB
varied from 0.5 – 5 mg/L over a period of 6 weeks. A yellow substrate
was released in the medium into the medium during growth of JS6 on
benzene. Doubling time on benzene was 5h.
(Spain and Nishino,
1987)
1,2-, 1,4-DCB Not reported
Material: soil and groundwater from contaminated site. Removal of
54% of 1,2-DCB within 7 days, with no accumulation of 3-
chlorocatechol. DCB was transformed by ortho pathway. Groundwater
concentrations approximately 40 to 50 mg/L.
(Nishino, et al., 1992)
1,2-, 1,3-DCB Pseudomonas sp. strain
JS150
For 1,2-, and 1,3-DCB metabolism, no products were identified in
HPLC, which might indicate complete metabolism of these
compounds.
(Haigler, et al., 1992)
1,4-DCB, CB
Pseudomonas sp. strain
JS1474, JS1344, JS700,
JS701, JS150
Study comparing JS150 with indigenous population from the site. Site
with historical CB contamination showed transformation of CB and
DCBs, proving that inoculating the site with specific CB-degrading
culture is not necessary, if oxygen is widely present.
(Nishino, et al., 1993)
DCBs Burkholderia sp. strain
PS14
The three DCBs isomers were metabolized within 1 hour from initial
concentration of 500 nM.
(Rapp and Timmis,
1999)
92
Table A.7 Anaerobic transformation of chlorobenzenes reported in the literature
Substrate Organism reported to
degrade / transform Comment Reference
Trichlorobenzene
and
dichlorobenzene
Not reported
Experiment done in anaerobic sediment column testing
trichlorobenzenes and its products. Dichlorination observed until
MCB.
(Bosma, et al., 1988)
DCBs Not reported
Microcosm study done with 1,2-, 1,3-, 1,4-DCB mixed and separated.
1,2-DCB showed the highest dehalogenation rate whereas 1,4-DCB
showed was the slowest. Benzene was accumulated over 5000 µmol/l
in the bottles. Material used for microcosms from Chambers Works
sediments.
(Fung, et al., 2009)
1,2-, 1,3, -1,4-
DCB, MCB Dehalobacter spp. Responsible for reductive dehalogenation. (Nelson, et al., 2011)
MCB and benzene Not reported Chlorobenzene produced benzene that was degraded transformed to
CO2 and CH4. MCB concentration of approximately 700 µM. (Liang, et al., 2013)
1,2-, 1,3-, 1,4-
DCB and other
chlorinated
benzenes
Dehalobacter spp. strains
12DCB1, 13DCB1,
14DCB1
1,2-DCB was dehalogenated to MCB by 12DCB1.
13DCB1 strain used 1,2- and 1,3-DCB as substrates. 14DCB1 used
1,2- and 1,4-DCB as substrates.
(Nelson, et al., 2014)
93
Table A.8 Aerobic degradation of dichloronitrobenzenes reported in the literature
Substrate Condition Organism reported to degrade / transform Comment Reference
3,4-DCNB Aerobic
Acidovorax sp. strain JS 3050 (99% similarity to
Acidovorax sp. JS42)
Diaphorobacter sp. strain JS 3052
Experiments done at 30°C, pH around 7.
Initial concentrations of 0.3mM. Fluidized
bed reactor experiments were conducted
with the samples and isolates. This study
was conducted with soil and groundwater
samples collected from the same field site
in Brazil. These samples were collected at
the same time as the soil and groundwater
samples used to prepare the microcosm
study described in Chapter 3 of this thesis.
(Palatucci, 2017)
2,3-DCNB Aerobic Pseudomonas sp. strain JS 3051
94
Appendix B. Supplementary information for Chapter 2
Table B.1 Chemical compounds and solvents used
Group Compound Purity Brand
Aniline and
chloroanilines
Aniline 99.50% Sigma Aldrich
2-CA 99% Sigma Aldrich
3-CA 99% Sigma Aldrich
4-CA 98% Sigma Aldrich
2,3-DCA 99% Sigma Aldrich
2,5-DCA 99% Sigma Aldrich
3,4-DCA 99.90% Sigma Aldrich
Chlorobenzenes
1,2-DCB 99% Sigma Aldrich
1,3-DCB 98% Sigma Aldrich
1,4-DCB 99% Sigma Aldrich
Chloronitrobenzenes
2,3-DCNB 99.90% Sigma Aldrich
2,5-DCNB 99% Sigma Aldrich
3,4-DCNB 99% Sigma Aldrich
Solvents
Acetonitrile - BDH
Acetone - Caledon
Methanol - BDH
95
Figure B.1 Calibration curve for methane, benzene, and DCBs in GC. X axis represent the area in the
graph and Y axis represent concentration (mg/L) of each compound.
96
7
Figure B.2 Calibration curves for anilines, chloroanilines, dichloroanilines, and
dichloronitrobenzenes in HPLC. X axis represent the area in the graph and Y axis represent
concentration (mg/L) of each compound.
97
Figure B.2 (cont.) Calibration curves for anilines, chloroanilines, dichloroanilines, and
dichloronitrobenzenes in HPLC. X axis represent the area in the graph and Y axis represent
concentration (mg/L) of each compound.
98
Appendix C. Supplementary Information for Chapter 3
Figure C.1 Soil samples used for microcosms study #1. Both sets divided into shallow (A) and deep
(B) portions. A) sediment description when samples arrived in Toronto in 2015; B) target COIs in four
sets of samples. NO82 and NO83 represent different locations where the soil samples were collected
from; mbgs = meters below ground surface. DCB = dichlorobenzene, DCA = dichloroaniline, DCNB=
dichloronitrobenzene, CA = chloroaniline.
A.
B.
99
Table C.1 Average aerobic degradation rates (mg/L/day) per site in the microcosms. CA =
chloroaniline, DCA = dichloroaniline, DCB = dichlorobenzene, DCNB = dichloronitrobenzene. Values in
red are the fastest degradation rates (>0.2 mg/L/day).
1A 1B 2A 2B
AC nt nt nt 1.1
Vit nt nt nt NA
AC 0.78 nt 0.4 0.21
Vit 0.13 nt NA 0.36
AC nt nt 0.2 0.28
Vit nt nt NA NA
AC nt nt 0.15 0.2
Vit nt nt NA NA
AC 0.86 nt 0.11 0.12
Vit 0.09 nt NA NA
AC 0.55 nt 0.09 0.09
Vit 0.53 nt NA NA
AC 0.1 nt 0.2 0.14
Vit 0.08 nt NA NA
AC - nt - -
Vit - nt - -
AC - nt - -
Vit - nt - -
AC - nt - -
Vit - nt - -
AC NA - 0.11 0.18
Vit 0.19 - NA NA
AC - - nt nt
Vit - - nt nt
AC - - nt nt
Vit - - nt nt
AC = active control / Vit = vitamins/ nt = not tested in this set / "-" means no degradation occurred
* = not complete degradation
NA = not applicable due to not continuos measurement
CA = chloroaniline / DCA = dichloroaniline / DCB = dichlorobenzene / DCNB = dichloronitrobenzene
Dichloro-
benzene
Dichloro-
nitrobenzene
3,4-DCNB
1,2-DCB
1,3-DCB
1,4-DCB
2,3-DCNB
2,5-DCNB
Average aerobic degradation rate (mg/L/day) per site
Aniline
Treatment in
microcosm
Aniline and
chloroanilines
2-CA
3-CA
4-CA
2,3-DCA
2,5-DCA*
3,4-DCA
Group Contaminant
100
Figure C.1 Concentration versus time in an aerobic active control microcosm from site 2B. X axis show the elapsed time (in days) since
the beginning of the experiment and Y axis represent the contaminants concentration (mg/L) for each compound tested. Figure prepared by
Line Lomheim.
101
Table C.2 Average anaerobic transformation rates (mg/L/day) per site in the microcosms. CA =
chloroaniline, DCA = dichloroaniline, DCB = dichlorobenzene, DCNB = dichloronitrobenzene. Values in
red are the fastest degradation rates (>0.2 mg/L/day).
1A 1B 2A 2B
AC nt nt - -
Don nt nt - -
Sulf nt nt - -
Nit nt nt - -
AC - nt - -
Don - nt - -
Sulf - nt - -
Nit - nt - -
AC nt nt - nt
Don nt nt - nt
Sulf nt nt - nt
Nit nt nt - nt
AC nt nt - nt
Don nt nt - nt
Sulf nt nt - nt
Nit nt nt - nt
AC - nt - -
Don 0.08 nt - -
Sulf - nt 0.02 -
Nit - nt - -
AC - nt - -
Don 0.07* nt - -
Sulf - nt - -
Nit - nt - -
AC - nt - -
Don 0.1 nt 0.34 -
Sulf - nt 0.03 -
Nit - nt - -
2,3-DCNB nt nt nt nt nt
AC nt nt 0.02 -
Don nt nt 0.37 0.38
Sulf nt nt 0.03 -
Nit nt nt 0.01 -
AC nt nt 0.02 -
Don nt nt 0.31 0.43
Sulf nt nt 0.03 -
Nit nt nt 0.03 -
AC - - - -
Don 0.27 - 0.04 -
Sulf - - - -
Nit - NA - -
AC - - nt nt
Don - - nt nt
Sulf - - nt nt
Nit - NA nt nt
AC - - nt nt
Don - - nt nt
Sulf - - nt nt
Nit - NA nt nt
* = not complete reaction
NA = not applicable due to not continuos measurement
CA = chloroaniline / DCA = dichloroaniline / DCB = dichlorobenzene / DCNB = dichloronitrobenzene
Dichloro-
benzene
AC = active control / Don = donor amended / Sulf = sulfate amended / Nit = nitrate amended / nt = not tested in this
set / "-" means no degradation occurred
1,2-DCB
1,3-DCB
1,4-DCB
3,4-DCA
Aniline and
chloroanilines
2,5-DCNB
3,4-DCNB
Dichloro-
nitrobenzene
Group ContaminantAverage anaerobic biotransformation rate (mg/L/day) per site
2,3-DCA
2,5-DCA
Treatment in
microcosm
Aniline
2-CA
3-CA
4-CA
102
Figure C.2 Anaerobic nitrate amended microcosm. Biotransformation of the three dichlorobenzene isomers after 900 days of experiment. As the
bottle was not sampled for a long period (~700 days), the dashed lines indicate a long period with incertanty. X axis represent time (days) and Y axis
represent concentration of the compound (mg/L). CA = chloroaniline, DCA = dichloroaniline, DCB = dichlorobenzene, DCNB =
dichloronitrobenzene.
0
1
2
3
4
5
6
7
8
9
10
0
1
2
3
4
5
6
7
8
9
10
0 200 400 600 800 1000
Co
nce
ntr
atio
n m
eth
ane
(m
g/L
)
Co
nce
ntr
atio
n D
CB
s an
d M
CB
(m
g/L)
Time (days)
Biotransformation overtime in anaerobic nitrate amended microcosm from site 1B
MCB
1,4-DCB
1,3-DCB
1,2-DCB
pH site 1B: 4.6 - 5.6 (not changing)
Methane
Time points for DNA sampling
Time points for nitrate amended
103
Figure C.4 Concentration of SVOCs versus time in anaerobic electron donor amended microcosm from site 1A. X axis show
the elapsed time (in days) since the beginning of the experiment and Y axis represent the contaminants concentration (mg/L) for
each compound tested. Figure prepared by Line Lomheim.
104
Figure C.5 Concentration of VOCs versus time in anaerobic electron donor amended microcosm from site 1A. X axis show
the elapsed time (in days) since the beginning of the experiment and Y axis represent the contaminants concentration (mg/L) for
each compound tested. Figure prepared by Line Lomheim.
Figure 6.4 Concentration of VOCs versus time in anaerobic electron donor amended microcosm from site 1A. X axis show
the elapsed time (in days) since the beginning of the experiment and Y axis represent the contaminants concentration (mg/L) for
each compound tested. Figure prepared by Line Lomheim.
105
Figure C.6 Concentration of VOCs versus time in anaerobic electron donor amended microcosm from site 2A. X axis show
the elapsed time (in days) since the beginning of the experiment and Y axis represent the contaminants concentration (mg/L) for
each compound tested. Figure prepared by Line Lomheim.
106
Appendix D. Supplementary information for Chapter 4
Figure D.1 Sample location for anaerobic microcosms study #2, assessing aniline and
chloroanilines degradation. Well sampled: DW-05. Samples were collected at 48 mbgs (meters below
ground surface). Groundwater flows towards north. Figure prepared by CH2M.
107
Methodology: Aniline and chloroanilines anaerobic microcosm study #2
New microcosms bottles were set up according to the procedure described in Section 2.2, except for the
sample amount that was different for these bottles. In this case, 140 mL of groundwater and 15 - 20 g of
soil was mixed in 250 mL Boston round bottles, leaving a headspace of approximately 100 mL. These
bottles received the treatments below, in duplicates:
a. Sterile control: 1.4 mL of HgCl2 (5% stock, final concentration of 0.05%) and 0.56 mL of NaN3
(5% stock, final concentration of 0.02%), to inhibit biological activity;
b. Active control: soil and groundwater from the site;
c. Electron donor amended: 170 µL of sodium lactate stock (0.7 M stock, final concentration 100
mg/L), and 17.7µL of neat ethanol (final concentration of 100 mg/L);
d. Sulfate amended: 700 µL of sodium sulfate stock solution (400 mM, final concentration of 2
mM);
e. Nitrate amended: 700 µL of sodium nitrate stock solution (400 mM, final concentration of 2
mM).
A concentration of 1 mg/L of resazurin, a redox indicator, was added in two of the bottles to indicate
redox potential in the bottles: an electron donor and a sulfate amended. The pH was adjusted to 7.0 by
adding the previously described bicarbonate solution, and pH was monitoring throughout the first few
months to ensure the pH remained neutral. Mineral medium (described in Section 2.1.2) was added in two
bottles fed with aniline and chloroaniline to determine if it would stimulate the degradation when
compared to the microcosms prepared with groundwater from the site. The complete treatment table for
this study is presented in Table D.1.
Once the bottles were prepared, a final concentration of 10 mg/L of aniline and chloroaniline were added.
The aniline stock solution was prepared by mixing 78.3 µL of neat aniline in an 8 mL glass vial capped
with MininertTM cap with 7920 mg of MiliQ water. The final stock solution concentration was 10,000
mg/L. The chloroaniline stock solution was prepared by mixing 0.5 g of each isomer (2-CA, 3-CA, and 4-
CA) in a glass vial capped with MininertTM cap. The final stock solution concentration was 224,502 mg/L.
For six months, these bottles were sampled and analyzed by HPLC to assess SVOC concentrations,
following procedures described in Section 2.2.3.
108
Table D.2 Treatment table for anaerobic microcosms study #2. All the bottles were set up in duplicated, in a total of 18 bottles. The solutions
mentioned in the table were prepared according to Chapter 2.
COI Treatment Soil
Ground-
water
Head-
space Resazurin
HgCl2
(5%)
NaN3
(5%)
Lactate
stock
(0.7M)
Ethanol
(neat)
Sulfate
stock
(400mM)
Nitrate
stock
(400mM)
vol. in mL mL mL µL mL mL µL µL µL µL
Aniline
+ CAs Sterile controls
15 140 100 1.4 0.56
15 140 100 1.4 0.56
Aniline
Active controls 15 140 100
15 140 100
Electron donor
(ethanol and lactate)
15 140 100 140 170 17.7
15 140 100 170 17.7
Sulfate amended 15 140 100 140 700
15 140 100 700
Nitrate amended 15 140 100 700
15 140 100 700
CAs
(2-CA,
3CA, 4-
CA)
Active controls 15 140 100
15 140 100
Electron donor
(ethanol and lactate)
15 140 100 170 17.7
15 140 100 170 17.7
Electron donor and
pH7
15 140 100 170 17.7
15 140 100 170 17.7
Aniline
and
CAs
Soil + medium: pH7 &
electron donor
amended
15 140 100 170 17.7
15 140 100 170 17.7
109
Figure D.2 Anaerobic transformation graphs for microcosms study #2, assessing aniline and
chloroanilines. All the graphs show average of the duplicates after HPLC analysis. X axis represent
time (days) and Y axis represent concentration of the compound (mg/L). CA = chloroaniline, DCA =
dichloroaniline, DCB = dichlorobenzene, DCNB = dichloronitrobenzene.
110
Figure D.2 (cont.) Anaerobic transformation graphs for microcosms study #2, assessing aniline
and chloroanilines. All the graphs show average of the duplicates after HPLC analysis. X axis
represent time (days) and Y axis represent concentration of the compound (mg/L). CA = chloroaniline,
DCA = dichloroaniline, DCB = dichlorobenzene, DCNB = dichloronitrobenzene.
111
Table D.3 Treatment table for aerobic test performed in Camaçari laboratory with puddle water.
ASC = aerobic sterile control, AAC = aerobic active control, APH = aerobic pH. A
ero
bic
Treatment Name
Ground-
water
Boiled tap
water Headspace
pH
adjusted
(pH = 7)
number of
bottles
mL mL mL
Sterile controls
ASC-1 100 150 no 1
ASC-2 100 150 no 1
ASC-3 100 150 no 1
Active controls
AAC-1 100 150 no 1
AAC-2 100 150 no 1
AAC-3 100 150 no 1
pH adjustment
APH-1 100 150 yes 1
APH-2 100 150 yes 1
APH-3 100 150 yes 1
Total 600 300 9
112
Figure D.3 Aerobic degradation from test conducted in Camaçari with puddle water. A) Sterile
controls with natural pH; B) Active controls with natural pH; C) pH adjusted to 7. X axis represent time
(days) and Y axis represent concentration of the compound (mg/L). CA = chloroaniline, DCA =
dichloroaniline, DCB = dichlorobenzene, DCNB = dichloronitrobenzene.
A
A
B
B
C
C
113
Methodology for Section 4.3: Cultivating pure and highly enrichment cultures from
collaborating laboratories
Plates containing pure cultures and sand from the bioreactor from the University of West Florida
were sent to the University of Toronto. Before receiving the samples, mineral medium was
prepared, as described in Section 2.1.2, but resazurin, vitamin stock and FeS were not added to
the medium. This batch of mineral medium was also prepared using half the concentration of the
medium stock solutions as described before. The microorganisms from the agar plates and from
FBR sand were grown using the procedure described below. Figure D.4a and Figure D.4b show
a diagram of the culturing process for both pure cultures and the sand sample from the
bioreactor.
In Figure D.4a, the steps were:
a. Preparation of flasks: Two feeding stock solutions were prepared in acetone with
final concentrations of 39.8 g/L of 2,3-DCNB and 36.3g/L of 3,4- DCNB. In 5
autoclaved Erlenmeyer flasks (represented by F1 to F5 in the figure), the COIs were
added, for a final concentration of 15 mg/L in the liquid phase of each compound as
follows: only 2,3-DCNB was added to F1, only 3,4-DCNB was added to F2 and F3,
and both stock solutions were added to F4 and F5. Inside the fume hood, with a gas
tight glass syringe, the stock solution was added to each flask, the acetone evaporated
from the flask for 5 minutes, and 230 mL of mineral medium was added using a glass
pipettor. A similar procedure was done for an additional four 250 mL Boston round
bottles (represented by B1 to B4 in the figure), by adding both stock solutions in the
empty bottles, allowing the acetone to evaporate, and adding 50 mL of mineral
medium in each bottle. DCNB-containing flasks and bottles were incubated for 1.5
hours at 30°C, shaking at 200 rpm, to allow the COIs that had been dried on the glass
surface dissolve in the liquid phase. During this incubation period, the flasks and
bottles were covered with aluminum foil.
b. Inoculum: Each flask was prepared with 230 mL of medium and COIs. From four of the
flasks (F1 to F4), 10 mL was transferred to each of the 3 autoclaved glass tubes (T1 to
114
T4) using a glass pipettor. The remaining volume in each of these four flasks was 200
mL. In the fifth flask, 230 mL remained, and each bottle still had 50 mL of solution.
Pieces of the agar plates containing the pure cultures (orange, green, and blue, Figure
D.4a) were used to inoculate three flasks (F1, F2, and F3, Figure D.4a) and three tubes
(T1, T2, and T3, Figure D.4a), using an aseptic metal stem loop that was alcohol
sterilized and flamed between each flask inoculation. The sand from the FBR (yellow,
Figure D.4a) was transferred from the falcon tubes to two flasks (F4 and F5, Figure
D.4a), a tube (T4, Figure D.4a), and the four bottles (B1 to B4, Figure D.4a) by pouring
in the same volume in each of them. A 50 mL glass pipettor was also used to transfer the
sand to the tubes. The bottles were capped with MininertTM caps and a final concentration
of 10 mg/L of 1,2-DCB was added to each bottle.
c. Incubation: All 5 flasks, 12 tubes, and 4 bottles were incubated in a 30°C shaker at 200
rpm. After 2 days of incubation, the flasks and tubes with sand were yellow and the COI
concentrations in all the flasks and tubes were zero.
d. Culture combination: To ensure the COIs were not evaporated during incubation, the
contents of the flasks were completely transferred to autoclaved Boston round bottles. In
Figure D.4a, each flask is now represented by a bottle with the original name, and the
tubes were combined into one bottle, also with the original name.
As the COI concentrations were zero in all the flaks and tubes after incubating over the
weekend, the same COI in acetone evaporation method was performed again for each of
the newly transferred bottles, to a final concentration of 15 mg/L. The bottles were
incubated on a 30°C shaker at 200 rpm. Over a period of 9 days, these bottles were fed
twice, and incubated under the same conditions.
e. Growth/degradation: After incubating and refeeding the bottles, the contents of the
bottles were transferred again into 10 bottles (J1 to J10, Figure D.4a) and the bottles were
fed for the last time. In Figure D.4a, green check marks represent bottles that degraded
COIs in this last step (J1, J3, J5, J7, and J8) and red crosses are bottles did not (J2, J4, J6,
J9, J10).
115
Continuing in Figure D.4b, the steps were:
f. Bottles that showed degradation: The bottles described in the previous section that
degraded COIs in the last feeding (J1, J3, J5, J7, and J8, Figure D.4b).
g. Sample collection: From each of the active bottles, three types of samples were
collected:
DNA samples: 2 mL of culture was pipetted from each bottle, placed into a 2 mL
screw cap microtube and centrifuged for 25 min at 10,000 rpm. The supernatant
was removed using a glass Pasteur pipette. The pellet was stored in the freezer at
-80°C until DNA extraction, followed by 16S rRNA amplicon sequencing and
qPCR, as described in Section 2.5.5. The results of this analysis will be
described in Chapter 5.
Frozen active cultures: 40 mL from each bottle was pipetted to 50 mL falcon
tubes, centrifuged at 6,000xg for 30 min. The supernatant was removed from
tubes and the pellet was transferred to a 2 mL screw cap microcentrifuge tube.
The tubes were stored at -80°C. These pellets can be used in the future to culture
for further experimentation.
Sample for Culture Mix preparation: 3 mL from each bottle was collected using
a glass pipettor and combined into a 40 mL glass vial with MininertTM cap. This
combination of culture will be hereby referred to as the culture mix. The culture
mix acted as an active inoculum in inactive microcosms, explained in the next
section.
116
Figure D.4 Process of growing aerobic cultures in the laboratory.
117
Figure D.4 (cont.) Process of growing aerobic cultures in the laboratory.
118
Table D.4 Experiment set up to test if aerobic microcosms from sites 2A and 1B inoculated with culture mix would show more degradation.
CA = chloroaniline, DCA = dichloroaniline, DCB = dichlorobenzene, DCNB = dichloronitrobenzene.
Inactive
microcosm name
Microcosm
description
# of
bottles What was done
Treatment and average pH of
duplicated
Average pH
of duplicates
after
treatment
Contaminants in
bottles
Cam-2A-AAC-1
AAC =
aerobic active
control from
set 2A
2 Combine content from 3
bottles in a larger glass bottle
and split in 8 autoclaved
Boston round bottles (150 mL
capacity) using a glass
pipettor (approximately 35
mL of groundwater and 2
scoops of soil).
Continuing with maintenance
before combining 5.4
2,3-DCNB
3,4-DCNB
2,5-DCA
1,2-DCB
2-CA, 3-CA,
4-CA
Cam-2A-AAC-2 2 Adjust pH to neutral 7.1
Cam-2A-AAC-3
2 Inoculate with culture mix, do
not change pH 5.3
2 Inoculate with culture mix
and adjust pH to neutral 7.2
Cam-1B-AAC-1
AAC =
aerobic active
control from
set 1B
2 Combine content from 3
bottles in a larger glass bottle
and split in 8 autoclaved
Boston round bottles (150 mL
capacity) using a glass
pipettor (approximately 50
mL of groundwater and 2
scoops of soil)
Continuing with maintenance
before combining 5.0
1,2-DCB
2-CA
3-CA
4-CA
Cam-1B-AAC-2 2 Adjust pH to neutral 6.9
Cam-1B-AAC-3
2 Inoculate with culture mix, do
not change pH 5.1
2 Inoculate with culture mix
and adjust pH to neutral 6.8
119
Table D.5 Influence of pH in microcosms and treatments in the bottles. CA = chloroaniline, DCA = dichloroaniline, DCB = dichlorobenzene,
DCNB = dichloronitrobenzene.
Inactive
microcosm
name
Microcosm
description # of bottles
Bottle
capacity
(mL)
Treatment Original
pH
pH after
adjustment
Contaminants
in the bottle
when test was
set up
Compounds
previously
degraded
Cam-1A-AAM-1 AAM =
aerobic
vitamins
amended
(site 1A)
original
bottle 250
Adjust pH to neutral
5.8 6.9 2,3DCNB
(3 mg/L) 2-CA
3-CA
4-CA
Cam-1A-AAM-2 original
bottle 250 5.8 6.9
2,5DCNB
(6 mg/L)
Cam-1A-AAM-3 original
bottle 250 5.5 6.9
3,4DCNB
(10 mg/L)
Cam-2A-AAM-1 AAM =
Aerobic
vitamins
amended
(site 2A)
original
bottle 250 Keep bottle as is 5.5 -
3,4-DCNB
2,5-DCNB
2,5-DCA
1,2-DCB
2-CA
3-CA
4-CA
3,4-DCA
2,3-DCA
1-2DCB (only
in the second
replicate)
Cam-2A-AAM-2 original
bottle 250
Adjust pH to neutral
5.5 6.9
Cam-2A-AAM-3 original
bottle 250 5.5 6.9
Cam-2B-AAC-1 AAC =
aerobic
active
controls
(site 2B)
2* 150 Keep bottle as is 4.6 -
2,5-CA
2,3-DCNB*
2-CA
3-CA
4-CA
3,4-DCA
2,3-DCA
Cam-2B-AAC-2 2* 150 Change pH to an
intermediate value 4.7 5.8
Cam-2B-AAC-3 2* 150 Adjust pH to neutral 4.7 7
* This test was done by combining the content from 3 microcosms and splitting into 6 bottles. Details in the text, Section 4.4.2.
120
Figure D.5 Results of pH adjustment in aerobic vitamin amended microcosms from site 1A. Each
graph represents one of the triplicates, as mentioned in Table D.4. X axis represent time (days) and Y axis
represent concentration of the compound (mg/L). CA = chloroaniline, DCA = dichloroaniline, DCB =
dichlorobenzene, DCNB = dichloronitrobenzene.
0
2
4
6
8
10
12
0 50 100 150 200
Conce
ntr
atio
n (
mg/L
)
Time (days)
Cam-1A-AAM-1 (pH adjusted to neutral)pH = 6.9
2,3-DCNB
3,4-DCNB
0
2
4
6
8
10
12
0 50 100 150 200
Co
nce
ntr
atio
n (
mg/L
)
Time (days)
Cam-1A-AAM-2 (pH adjusted to neutral)pH = 6.9
2,5-DCNB
3,4-DCNB
0
2
4
6
8
10
12
0 50 100 150 200
Co
nce
ntr
atio
n (
mg/L
)
Time (days)
Cam-1A-AAM-3 (pH adjusted to neutral)pH = 6.9
3,4-DCNB
121
Figure D.6 Results of pH adjustment in aerobic vitamin amended microcosms from site 2A. A)
microcosms kept as is. B and C) pH adjusted to 7. X axis represent time (days) and Y axis represent
concentration of the compound (mg/L). CA = chloroaniline, DCA = dichloroaniline, DCB =
dichlorobenzene, DCNB = dichloronitrobenzene.
0
5
10
15
20
0 50 100 150 200
Co
nce
ntr
atio
n (
mg/L
)
Time (days)
Cam-2A-AAM-2 (pH adjusted to neutral)pH = 6.9
2,5-DCA
2,5-DCNB
3,4-DCNB
0
2
4
6
8
10
12
0 50 100 150 200
Conce
ntr
atio
n (
mg/L
)
Time (days)
Cam-2A-AAM-3 (pH adjusted to neutral)pH = 6.9
2,5-DCA
2,5-DCNB
3,4-DCNB
1,2-DCB
0
2
4
6
8
10
12
0 50 100 150 200
Conce
ntr
atio
n (
mg/L
)
Time (days)
Cam-2A-AAM-1 (bottle kept as is) pH = 5.5
2,5-DCA
2,5-DCNB
3,4-DCNB
1,2-DCB
A
B
C
122
Figure D.7 Results of pH adjustment in aerobic active control microcosms from site 2B. A) pH was
kept as natural. B) pH was adjusted to an intermediate value (5.8). C) pH was adjusted to neutral. X axis
represent time (days) and Y axis represent concentration of the compound (mg/L). CA = chloroaniline,
DCA = dichloroaniline, DCB = dichlorobenzene, DCNB = dichloronitrobenzene.
A
B
C
123
Appendix E. Supplementary information for Chapter 5
Table E.2 Summary of samples used for microbial community analysis. Samples divided in type, sampling date, sample name, site (for
microcosms only), conditions (aerobic or anaerobic), location at the site, groundwater origin, soil origin, and depth (meters below ground surface)
# Type of sample Sampling
date Sample name
Site (for
microcosms
and soil
only)
Condition
a = aerobic
an=
anaerobic
Specific
location at
site
Ground-
water
origin
Soil
Origin
Depth
(mbgs)
1 microcosm 22-Feb-16 A1_AC_Day070an 1A an NPAD PM19 N083 5.5
2 microcosm 13-May-16 A1_AC_Day151an 1A an NPAD PM19 N083 5.5
3 microcosm 2-Jun-16 A1_AC_Day171an 1A an NPAD PM19 N083 5.5
4 microcosm 28-Jun-16 A1_AC_Day197an 1A an NPAD PM19 N083 5.5
5 microcosm 11-Aug-16 A1_AC_Day241an 1A an NPAD PM19 N083 5.5
6 microcosm 1-Nov-16 A1_AC_Day323an 1A an NPAD PM19 N083 5.5
7 microcosm 1-Nov-16 A1_AC1_Day323a 1A a NPAD PM19 N083 5.5
8 microcosm 22-Feb-16 A1_AC2_Day070a 1A a NPAD PM19 N083 5.5
9 microcosm 13-May-16 A1_AC2_Day151a 1A a NPAD PM19 N083 5.5
10 microcosm 28-Jun-16 A1_AC2_Day197a 1A a NPAD PM19 N083 5.5
11 microcosm 11-Aug-16 A1_AC2_Day241a 1A a NPAD PM19 N083 5.5
12 microcosm 1-Nov-16 A1_AC2_Day323a 1A a NPAD PM19 N083 5.5
13 microcosm 1-Nov-16 A1_AC3_Day323a 1A a NPAD PM19 N083 5.5
14 microcosm 11-Aug-16 A1_Don1_Day241an 1A an NPAD PM19 N083 5.5
15 microcosm 1-Nov-16 A1_Don1_Day323an 1A an NPAD PM19 N083 5.5
16 microcosm 13-May-16 A1_Don2_Day151an 1A an NPAD PM19 N083 5.5
17 microcosm 2-Jun-16 A1_Don2_Day171an 1A an NPAD PM19 N083 5.5
18 microcosm 28-Jun-16 A1_Don2_Day197an 1A an NPAD PM19 N083 5.5
19 microcosm 11-Aug-16 A1_Don2_Day241an 1A an NPAD PM19 N083 5.5
20 microcosm 1-Nov-16 A1_Don2_Day323an 1A an NPAD PM19 N083 5.5
21 microcosm 2-Jun-16 A1_Don3_Day171an 1A an NPAD PM19 N083 5.5
22 microcosm 28-Jun-16 A1_Don3_Day197an 1A an NPAD PM19 N083 5.5
23 microcosm 11-Aug-16 A1_Don3_Day241an 1A an NPAD PM19 N083 5.5
124
# Type of sample Sampling
date Sample name
Site (for
microcosms
and soil
only)
Condition
a = aerobic
an=
anaerobic
Specific
location at
site
Ground-
water
origin
Soil
Origin
Depth
(mbgs)
24 microcosm 1-Nov-16 A1_Don3_Day323an 1A an NPAD PM19 N083 5.5
25 microcosm 11-Aug-16 A1_Nit2_Day241an 1A an NPAD PM19 N083 5.5
26 microcosm 1-Nov-16 A1_Nit2_Day323an 1A an NPAD PM19 N083 5.5
27 microcosm 1-Nov-16 A1_Sulf2_Day323an 1A an NPAD PM19 N083 5.5
28 microcosm 1-Nov-16 A1_Vit1_Day323a 1A a NPAD PM19 N083 5.5
29 microcosm 1-Nov-16 A1_Vit2_Day323a 1A a NPAD PM19 N083 5.5
30 microcosm 1-Nov-16 A1_Vit3_Day323a 1A a NPAD PM19 N083 5.5
31 microcosm 22-Feb-16 A2_AC_Day041an 2A an UN11&12 PM12 N082 5.1
32 microcosm 13-May-16 A2_AC_Day122an 2A an UN11&12 PM12 N082 5.1
33 microcosm 2-Jun-16 A2_AC_Day142an 2A an UN11&12 PM12 N082 5.1
34 microcosm 28-Jun-16 A2_AC_Day168an 2A an UN11&12 PM12 N082 5.1
35 microcosm 11-Aug-16 A2_AC_Day212an 2A an UN11&12 PM12 N082 5.1
36 microcosm 8-Nov-16 A2_AC_Day301an 2A an UN11&12 PM12 N082 5.1
37 microcosm 1-Nov-16 A2_AC1_Day316a 2A a UN11&12 PM12 N082 5.1
38 microcosm 22-Feb-16 A2_AC2_Day063a 2A a UN11&12 PM12 N082 5.1
39 microcosm 13-May-16 A2_AC2_Day144a 2A a UN11&12 PM12 N082 5.1
40 microcosm 28-Jun-16 A2_AC2_Day190a 2A a UN11&12 PM12 N082 5.1
41 microcosm 1-Nov-16 A2_AC2_Day316a 2A a UN11&12 PM12 N082 5.1
42 microcosm 1-Nov-16 A2_AC3_Day316a 2A a UN11&12 PM12 N082 5.1
43 microcosm 11-Aug-16 A2_Don1_Day212an 2A an UN11&12 PM12 N082 5.1
44 microcosm 8-Nov-16 A2_Don1_Day301an 2A an UN11&12 PM12 N082 5.1
45 microcosm 13-May-16 A2_Don2_Day122an 2A an UN11&12 PM12 N082 5.1
46 microcosm 28-Jun-16 A2_Don2_Day168an 2A an UN11&12 PM12 N082 5.1
47 microcosm 11-Aug-16 A2_Don2_Day212an 2A an UN11&12 PM12 N082 5.1
48 microcosm 8-Nov-16 A2_Don2_Day301an 2A an UN11&12 PM12 N082 5.1
49 microcosm 2-Jun-16 A2_Don3_Day142an 2A an UN11&12 PM12 N082 5.1
50 microcosm 8-Nov-16 A2_Don3_Day301an 2A an UN11&12 PM12 N082 5.1
51 microcosm 11-Aug-16 A2_Nit2_Day212an 2A an UN11&12 PM12 N082 5.1
125
# Type of sample Sampling
date Sample name
Site (for
microcosms
and soil
only)
Condition
a = aerobic
an=
anaerobic
Specific
location at
site
Ground-
water
origin
Soil
Origin
Depth
(mbgs)
52 microcosm 8-Nov-16 A2_Nit2_Day301an 2A an UN11&12 PM12 N082 5.1
53 microcosm 8-Nov-16 A2_Sulf2_Day301an 2A an UN11&12 PM12 N082 5.1
54 microcosm 1-Nov-16 A2_Vit2_Day316a 2A a UN11&12 PM12 N082 5.1
55 microcosm 22-Feb-16 B1_AC_Day070an 1B an NPAD PM19 N083 6
56 microcosm 13-May-16 B1_AC_Day151an 1B an NPAD PM19 N083 6
57 microcosm 28-Jun-16 B1_AC_Day197an 1B an NPAD PM19 N083 6
58 microcosm 11-Aug-16 B1_AC_Day241an 1B an NPAD PM19 N083 6
59 microcosm 1-Nov-16 B1_AC_Day323an 1B an NPAD PM19 N083 6
60 microcosm 22-Feb-16 B1_AC2_Day080a 1B a NPAD PM19 N083 6
61 microcosm 13-May-16 B1_AC2_Day161a 1B a NPAD PM19 N083 6
62 microcosm 28-Jun-16 B1_AC2_Day207a 1B a NPAD PM19 N083 6
63 microcosm 11-Aug-16 B1_AC2_Day251a 1B a NPAD PM19 N083 6
64 microcosm 1-Nov-16 B1_AC2_Day333a 1B a NPAD PM19 N083 6
65 microcosm 13-May-16 B1_Don2_Day151an 1B an NPAD PM19 N083 6
66 microcosm 28-Jun-16 B1_Don2_Day197an 1B an NPAD PM19 N083 6
67 microcosm 11-Aug-16 B1_Don2_Day241an 1B an NPAD PM19 N083 6
68 microcosm 1-Nov-16 B1_Don2_Day323an 1B an NPAD PM19 N083 6
69 microcosm 11-Aug-16 B1_Nit2_Day241an 1B an NPAD PM19 N083 6
70 microcosm 1-Nov-16 B1_Nit2_Day323an 1B an NPAD PM19 N083 6
71 microcosm 11-Aug-16 B1_Sulf2_Day241an 1B an NPAD PM19 N083 6
72 microcosm 1-Nov-16 B1_Sulf2_Day323an 1B an NPAD PM19 N083 6
73 microcosm 1-Nov-16 B1_Vit_Day333a 1B a NPAD PM19 N083 6
74 microcosm 22-Feb-16 B2_AC_Day047an 2B an UN11&12 PM12 N082 5.6
75 microcosm 13-May-16 B2_AC_Day128an 2B an UN11&12 PM12 N082 5.6
76 microcosm 2-Jun-16 B2_AC_Day148an 2B an UN11&12 PM12 N082 5.6
77 microcosm 28-Jun-16 B2_AC_Day174an 2B an UN11&12 PM12 N082 5.6
78 microcosm 11-Aug-16 B2_AC_Day218an 2B an UN11&12 PM12 N082 5.6
79 microcosm 8-Nov-16 B2_AC_Day307an 2B an UN11&12 PM12 N082 5.6
126
# Type of sample Sampling
date Sample name
Site (for
microcosms
and soil
only)
Condition
a = aerobic
an=
anaerobic
Specific
location at
site
Ground-
water
origin
Soil
Origin
Depth
(mbgs)
80 microcosm 13-May-16 B2_AC1_Day144a 2B a UN11&12 PM12 N082 5.6
81 microcosm 1-Nov-16 B2_AC1_Day316a 2B a UN11&12 PM12 N082 5.6
82 microcosm 22-Feb-16 B2_AC2_Day063a 2B a UN11&12 PM12 N082 5.6
83 microcosm 13-May-16 B2_AC2_Day144a 2B a UN11&12 PM12 N082 5.6
84 microcosm 28-Jun-16 B2_AC2_Day190a 2B a UN11&12 PM12 N082 5.6
85 microcosm 11-Aug-16 B2_AC2_Day234a 2B a UN11&12 PM12 N082 5.6
86 microcosm 1-Nov-16 B2_AC2_Day316a 2B a UN11&12 PM12 N082 5.6
87 microcosm 13-May-16 B2_AC3_Day144a 2B a UN11&12 PM12 N082 5.6
88 microcosm 1-Nov-16 B2_AC3_Day316a 2B a UN11&12 PM12 N082 5.6
89 microcosm 8-Nov-16 B2_Don1_Day307an 2B an UN11&12 PM12 N082 5.6
90 microcosm 13-May-16 B2_Don2_Day128an 2B an UN11&12 PM12 N082 5.6
91 microcosm 2-Jun-16 B2_Don2_Day148an 2B an UN11&12 PM12 N082 5.6
92 microcosm 28-Jun-16 B2_Don2_Day174an 2B an UN11&12 PM12 N082 5.6
93 microcosm 11-Aug-16 B2_Don2_Day218an 2B an UN11&12 PM12 N082 5.6
94 microcosm 8-Nov-16 B2_Don2_Day307an 2B an UN11&12 PM12 N082 5.6
95 microcosm 8-Nov-16 B2_Don3_Day307an 2B an UN11&12 PM12 N082 5.6
96 microcosm 11-Aug-16 B2_Nit2_Day218an 2B an UN11&12 PM12 N082 5.6
97 microcosm 8-Nov-16 B2_Nit2_Day307an 2B an UN11&12 PM12 N082 5.6
98 microcosm 11-Aug-16 B2_Sulf2_Day218an 2B an UN11&12 PM12 N082 5.6
99 microcosm 8-Nov-16 B2_Sulf2_Day307an 2B an UN11&12 PM12 N082 5.6
100 microcosm 1-Nov-16 B2_Vit2_Day316a 2B a UN11&12 PM12 N082 5.6
101 external culture 04-May-17 DF1_CBa - a - - - -
102 external culture 04-May-17 DF2_DCBa - a - - - -
103 external culture 17-Jun-17 DF3_4NTan - an - - - -
110 external culture 28-Jun-17 Jim1_3051_23DCNBa - a - - - -
111 external culture 28-Jun-17 Jim3_FBR_23DCNBa - a - - - -
112 external culture 28-Jun-17 Jim5_3050_34DCNBa - a - - - -
113 external culture 28-Jun-17 Jim7_FBR_34DCNBa - a - - - -
127
# Type of sample Sampling
date Sample name
Site (for
microcosms
and soil
only)
Condition
a = aerobic
an=
anaerobic
Specific
location at
site
Ground-
water
origin
Soil
Origin
Depth
(mbgs)
114 external culture 28-Jun-17 Jim8_FBR_12DCBa - a - - - -
115 soil spring-15 N082_deep_2B 2B - ** - N082 -
116 soil spring-15 N082_shallow_2A 2A - ** - N082 -
117 soil spring-15 N083_deep_1B 1B - ** - N083 -
118 soil spring-15 N083_shallow_1A 1A - ** - N083 -
104 groundwater 08-Aug-17 DW03B - - * * - -
105 groundwater 18-Jul-17 DW04 - - * * - -
106 groundwater 05-Jul-17 DW06 - - * * - -
107 groundwater 03-Aug-17 DW13 - - * * - -
108 groundwater 25-Nov-16 EHB - - - - - -
109 groundwater 25-Nov-16 IHB - - - - - -
119 groundwater 04-Aug-17 PM01 - - * * - -
120 groundwater 25-Nov-16 PM073_19 - - * * - -
121 groundwater 4-Jul-17 PM11 - - * * - -
122 groundwater 10-Aug-17 PM128_06 - - * * - -
123 groundwater 14-Aug-17 PM128_11 - - * * - -
124 groundwater 10-Jul-17 PM13 - - * * - -
125 groundwater 11-Jul-17 PM15 - - * * - -
126 groundwater 20-Jul-17 PM18 - - * * - -
127 groundwater 01-Aug-17 PM19 - - * * - -
128 groundwater 7-Jul-17 PM21 - - * * - -
129 groundwater 7-Jul-17 PM27 - - * * - -
130 groundwater 6-Jul-17 PM29 - - * * - -
131 groundwater 10-Jul-17 PM30 - - * * - -
132 groundwater 21-Jul-17 PM35 - - * * - -
133 groundwater 03-Aug-17 PM36 - - * * - -
134 groundwater 21-Jul-17 PM38 - - * * - -
135 groundwater 12-Jul-17 PM39 - - * * - -
128
# Type of sample Sampling
date Sample name
Site (for
microcosms
and soil
only)
Condition
a = aerobic
an=
anaerobic
Specific
location at
site
Ground-
water
origin
Soil
Origin
Depth
(mbgs)
136 groundwater 20-Jul-17 PM45 - - * * - -
137 groundwater 12-Jul-17 PMTW - - * * - -
138 groundwater (Cetrel) 25-Nov-16 TA01 - a - - - -
139 groundwater (Cetrel) 25-Nov-16 TA02 - a - - - -
140 groundwater (Cetrel) 25-Nov-16 TA04 - a - - - -
mbgs = meters below ground surface
*sample location on the map, Figure E.1.
** location for soil and groundwater used to prepare the microcosms shown in Figure 3.1.
129
Figure E.1 Groundwater sample location at the site. Black circles indicate where groundwater samples for DNA analysis
were collected from. Figure prepared by CH2M and modified for this thesis.
130
Table E.3 Details of the standard curves generated for qPCR. Summary includes average slopes, Y-intercepts, R2 and their corresponding standard
deviations for general Bacteria and general Archaea.
Legend: Eff = efficiency; R = coefficient of determination; N = number of standard curves used for the calculations; stdev = standard deviation.
Target Date slope y intercept R2 Eff N
Gen arch February 9, 2018 -3.413 36.356 0.999 96.3 3
Gen arch February 12, 2018 -3.49 36.54 0.999 93.4 3
Gen arch February 13, 2018 -3.497 33.267 0.999 93.2 3
Gen arch February 13, 2018 -3.529 36.954 0.999 92 3
Gen arch February 22, 2018 -3.313 31.852 0.998 100.4 3
Gen arch AVERAGE -3.45 34.99 0.999 95.06 3 STDEV 0.09 2.29 0.000 3.38
Gen bac January 31, 2018 -3.548 34.773 0.998 91.4 3
Gen bac February 5, 2018 -3.448 34.911 0.998 95 3
Gen bac February 6, 2018 -3.66 37.139 0.983 87.6 3
Gen bac February 7, 2018 -3.391 33.973 0.998 97.2 3
Gen bac February 8, 2018 -3.553 51.259 0.999 91.2 3
Gen bac February 8, 2018 -3.322 33.521 0.998 100 3
Gen bac February 15, 2018 -3.429 35.596 0.997 95.7 3
Gen bac February 16, 2018 -3.47 34.133 0.999 94.2 3
Gen bac February 22, 2018 -3.317 33.817 0.999 100.2 3
Gen bac AVERAGE -3.46 36.57 0.997 94.72 3 STDEV 0.11 5.62 0.005 4.18
131
Table E.4 Raw qPCR results. Results for microcosms samples (copies/mL), groundwater samples (copies/mL), soil samples (copies/g), and pure
culture samples (copies/mL).
# Sample name
Total bacteria
concentration in original
sample (copies/mL)
Detection limit
(copies/mL)
Total archaea
concentration in original
sample (copies/mL)
Detection limit
(copies/mL)
1 TA01 4.91E+09 1.91E+05 1.47E+07 6.73E+04
2 TA02 4.15E+09 1.91E+05 7.32E+06 6.73E+04
3 TA04 3.15E+09 1.91E+05 9.45E+06 6.73E+04
4 A1_Don1_Day323an 2.47E+09 1.46E+05 9.98E+08 4.57E+05
5 A1_Don3_Day323an 2.07E+09 1.46E+05 7.27E+08 7.05E+05
6 A1_Don3_Day197an 1.69E+09 1.46E+05 5.26E+08 4.57E+05
7 A1_Don1_Day241an 1.66E+09 1.46E+05 4.88E+08 4.57E+05
8 A1_Don2_Day323an 1.64E+09 1.46E+05 3.85E+08 4.57E+05
9 A1_Don2_Day197an 1.49E+09 1.46E+05 2.73E+08 4.57E+05
10 A1_Don2_Day151an 1.34E+09 1.46E+05 1.64E+08 4.57E+05
11 A1_Don3_Day241an 1.15E+09 1.46E+05 7.30E+08 7.05E+05
12 A1_Vit3_Day323a 1.14E+09 1.46E+05 3.24E+06 7.05E+05
13 A1_AC2_Day197a 8.12E+08 1.02E+05 4.40E+06 4.66E+04
14 A1_Sulf2_Day323an 8.06E+08 1.46E+05 1.16E+07 4.57E+05
15 A1_Vit2_Day323a 8.05E+08 1.02E+05 5.77E+06 4.66E+04
16 Jim3_FBR_23DCNBa 6.61E+08 5.10E+04 1.19E+05 2.02E+04
17 A1_AC_Day197an 6.51E+08 1.46E+05 2.35E+07 4.57E+05
18 A1_AC2_Day323a 6.27E+08 1.02E+05 5.84E+06 4.66E+04
19 A1_AC_Day323an 5.98E+08 1.46E+05 2.38E+07 4.57E+05
20 Jim7_FBR_34DCNBa 5.98E+08 5.10E+04 1.14E+05 2.02E+04
21 A1_Vit1_Day323a 5.96E+08 1.18E+05 5.56E+06 7.05E+05
22 A1_AC2_Day151a 5.76E+08 1.02E+05 3.96E+06 4.66E+04
23 A1_AC2_Day241a 5.73E+08 1.02E+05 2.70E+06 4.66E+04
24 Jim8_FBR_12DCBa 5.63E+08 5.10E+04 3.97E+04 2.02E+04
25 A1_AC_Day241an 5.24E+08 1.46E+05 2.76E+07 4.57E+05
26 A1_Don2_Day241an 5.23E+08 1.46E+05 1.40E+08 4.57E+05
27 A1_AC3_Day323a 4.76E+08 1.02E+05 2.92E+06 4.66E+04
28 A1_AC_Day151an 3.93E+08 1.46E+05 1.86E+07 7.05E+05
29 A1_AC2_Day070a 3.43E+08 1.02E+05 4.06E+06 4.66E+04
30 A1_AC1_Day323a 3.32E+08 1.02E+05 1.79E+06 4.66E+04
31 B1_Sulf2_Day323an 3.29E+08 1.45E+05 8.16E+04 4.66E+04
32 B1_Don2_Day323an 3.29E+08 1.45E+05 2.86E+08 4.66E+04
132
# Sample name
Total bacteria
concentration in original
sample (copies/mL)
Detection limit
(copies/mL)
Total archaea
concentration in original
sample (copies/mL)
Detection limit
(copies/mL)
33 A1_Nit2_Day241an 3.28E+08 1.45E+05 4.05E+06 4.57E+05
34 B1_Nit2_Day323an 2.75E+08 1.45E+05 2.34E+06 4.66E+04
35 A1_Don2_Day171an 2.67E+08 1.09E+05 1.40E+08 3.10E+05
36 A1_Nit2_Day323an 2.64E+08 1.45E+05 3.24E+06 4.57E+05
37 B1_AC2_Day333a 2.31E+08 1.18E+05 2.76E+06 7.05E+05
38 Jim5_3050_34DCNBa 2.10E+08 5.10E+04 1.27E+05 2.02E+04
39 A1_Don3_Day171an 2.08E+08 1.09E+05 1.73E+08 3.10E+05
40 B2_AC2_Day190a 1.94E+08 9.45E+04 5.86E+06 4.66E+04
41 B1_Don2_Day241an 1.89E+08 1.45E+05 3.19E+08 4.66E+04
42 B2_AC1_Day316a 1.86E+08 9.45E+04 3.89E+06 4.66E+04
43 B1_Sulf2_Day241an 1.86E+08 1.45E+05 7.51E+04 4.66E+04
44 A1_AC_Day070an 1.82E+08 1.09E+05 8.10E+06 3.10E+05
45 B2_AC2_Day234a 1.76E+08 9.45E+04 5.65E+06 4.66E+04
46 B1_AC2_Day207a 1.56E+08 1.45E+05 3.42E+06 4.57E+05
47 A2_Don2_Day168an 1.52E+08 1.45E+05 1.02E+07 4.66E+04
48 A1_AC_Day171an 1.50E+08 1.09E+05 2.23E+07 3.10E+05
49 B2_Don1_Day307an (*) 1.48E+08 9.45E+04 1.14E+09 4.66E+04
50 B1_Don2_Day197an 1.43E+08 1.45E+05 1.90E+08 4.66E+04
51 A2_Don3_Day301an 1.43E+08 1.45E+05 4.19E+07 4.66E+04
52 B1_Nit2_Day241an 1.41E+08 1.45E+05 9.71E+05 4.66E+04
53 B1_AC2_Day161a 1.38E+08 1.45E+05 2.55E+06 4.57E+05
54 B2_AC1_Day144a 1.36E+08 9.45E+04 9.56E+06 4.66E+04
55 B2_AC2_Day316a 1.34E+08 9.45E+04 3.18E+06 4.66E+04
56 B2_AC3_Day316a 1.25E+08 9.45E+04 2.27E+06 4.66E+04
57 B2_Vit2_Day316a 1.24E+08 9.45E+04 6.75E+06 4.66E+04
58 A2_AC1_Day316a 1.22E+08 1.46E+05 9.54E+05 7.05E+05
59 B2_AC2_Day063a 1.20E+08 9.45E+04 4.23E+06 4.66E+04
60 B2_AC3_Day144a 1.13E+08 9.45E+04 3.28E+06 4.66E+04
61 A2_Don2_Day122an 1.12E+08 1.46E+05 1.53E+06 7.05E+05
62 B2_AC_Day148an 1.11E+08 1.09E+05 4.16E+06 3.10E+05
63 B2_AC2_Day144a 1.06E+08 9.45E+04 5.14E+06 4.66E+04
64 A2_Don1_Day212an 1.05E+08 1.46E+05 3.20E+06 7.05E+05
65 B2_AC_Day047an 9.95E+07 1.09E+05 1.45E+07 3.10E+05
66 B2_Sulf2_Day307an 9.56E+07 1.02E+05 1.45E+07 4.66E+04
67 B1_Vit_Day333a 9.41E+07 1.45E+05 1.36E+06 4.57E+05
133
# Sample name
Total bacteria
concentration in original
sample (copies/mL)
Detection limit
(copies/mL)
Total archaea
concentration in original
sample (copies/mL)
Detection limit
(copies/mL)
68 B1_AC2_Day080a 9.40E+07 1.45E+05 2.27E+06 4.57E+05
69 B2_Don2_Day148an 9.20E+07 1.09E+05 1.82E+07 3.10E+05
70 N082_deep_2B 9.13E+07 1.06E+06 1.23E+08 3.43E+05
71 B2_Nit2_Day307an 8.73E+07 2.04E+05 1.33E+07 9.31E+04
72 B1_AC_Day241an 8.26E+07 1.45E+05 2.69E+07 4.57E+05
73 B2_Nit2_Day218an 8.10E+07 1.02E+05 1.40E+07 4.66E+04
74 DF1_CBa 8.04E+07 1.02E+03 0.00E+00 4.04E+02
75 A2_AC2_Day316a 7.78E+07 1.46E+05 1.86E+06 7.05E+05
76 B2_Don2_Day218an 7.66E+07 9.45E+04 3.10E+07 4.66E+04
77 B1_AC_Day151an 7.54E+07 1.45E+05 1.95E+07 4.57E+05
78 B1_Don2_Day151an 7.49E+07 1.45E+05 3.38E+07 4.66E+04
79 A2_Don1_Day301an 7.45E+07 1.46E+05 1.66E+06 7.05E+05
80 B1_AC2_Day251a 7.33E+07 1.45E+05 2.83E+05 4.57E+05
81 A2_Don2_Day301an 7.30E+07 1.45E+05 2.34E+07 4.66E+04
82 B2_Sulf2_Day218an 7.29E+07 9.45E+04 9.77E+06 4.66E+04
83 A2_AC2_Day144a 7.27E+07 1.46E+05 5.76E+06 7.05E+05
84 A2_Don2_Day212an 7.25E+07 1.45E+05 1.40E+07 4.66E+04
85 B2_AC_Day218an 7.24E+07 9.45E+04 1.14E+07 4.66E+04
86 B2_AC_Day174an 7.20E+07 9.45E+04 1.41E+07 4.66E+04
87 B2_Don2_Day174an 7.10E+07 9.45E+04 1.54E+07 4.66E+04
88 B1_AC_Day323an 6.93E+07 1.45E+05 1.86E+07 4.57E+05
89 A2_AC2_Day063a 6.78E+07 1.46E+05 1.88E+06 7.05E+05
90 A2_AC2_Day190a 6.75E+07 1.46E+05 3.59E+06 7.05E+05
91 B1_AC_Day197an 6.66E+07 1.45E+05 1.99E+07 4.57E+05
92 B2_Don3_Day307an 6.63E+07 9.45E+04 7.77E+07 4.66E+04
93 N083_shallow_1A 6.49E+07 8.45E+05 1.38E+07 2.98E+05
94 A2_Vit2_Day316a 6.03E+07 1.46E+05 1.72E+06 7.05E+05
95 B1_AC_Day070an 5.93E+07 1.45E+05 8.45E+06 4.57E+05
96 B2_Don2_Day307an 5.79E+07 9.45E+04 3.71E+07 4.66E+04
97 A2_Don3_Day142an 5.16E+07 1.09E+05 1.76E+07 3.10E+05
98 Jim1_3051_23DCNBa 4.37E+07 5.10E+04 0.00E+00 2.02E+04
99 B2_AC_Day128an 4.31E+07 1.18E+05 9.72E+06 7.05E+05
100 B2_AC_Day307an 3.96E+07 9.45E+04 6.11E+06 4.66E+04
101 B2_Don2_Day128an 3.78E+07 9.45E+04 5.78E+06 4.66E+04
102 A2_Nit2_Day301an 3.67E+07 9.45E+04 1.41E+06 4.66E+04
134
# Sample name
Total bacteria
concentration in original
sample (copies/mL)
Detection limit
(copies/mL)
Total archaea
concentration in original
sample (copies/mL)
Detection limit
(copies/mL)
103 A2_AC3_Day316a 3.20E+07 1.46E+05 4.61E+05 7.05E+05
104 N082_shallow_2A 2.82E+07 9.38E+05 2.18E+07 3.04E+05
105 A2_Nit2_Day212an 2.18E+07 9.45E+04 6.23E+05 4.66E+04
106 A2_AC_Day212an 2.02E+07 1.46E+05 1.78E+06 7.05E+05
107 N083_deep_1B 1.93E+07 7.86E+05 1.95E+07 2.77E+05
108 A2_AC_Day142an 1.78E+07 1.46E+05 2.63E+06 7.05E+05
109 A2_AC_Day168an 1.69E+07 1.46E+05 1.14E+06 4.66E+04
110 A2_AC_Day301an 1.16E+07 1.46E+05 1.33E+06 7.05E+05
111 EHB 1.14E+07 4.74E+02 1.55E+04 1.88E+02
112 A2_AC_Day122an 9.95E+06 1.46E+05 1.29E+06 7.05E+05
113 IHB 7.41E+06 1.67E+02 1.92E+03 6.62E+01
114 DF2_DCBa 7.19E+06 1.02E+03 5.86E+02 4.04E+02
115 A2_AC_Day041an 5.90E+06 1.09E+05 2.79E+06 3.10E+05
116 A2_Sulf2_Day301an 4.35E+06 9.45E+04 6.18E+05 4.66E+04
117 PM19 4.24E+06 3.90E+02 1.53E+04 1.38E+02
118 PM21 1.65E+06 3.32E+02 2.12E+04 1.17E+02
119 DW06 1.34E+06 1.46E+02 1.23E+04 5.16E+01
120 PM18 6.53E+05 2.37E+02 3.05E+04 8.36E+01
121 PM35 5.88E+05 1.68E+02 8.41E+02 5.93E+01
122 PM073_19 4.25E+05 1.04E+02 4.23E+03 4.11E+01
123 PM01 3.72E+05 1.25E+02 9.87E+03 4.39E+01
124 PM13 2.87E+05 1.25E+02 1.71E+04 4.39E+01
125 PM45 2.28E+05 2.02E+02 1.96E+04 7.14E+01
126 PMTW 2.17E+05 1.25E+02 8.80E+03 4.39E+01
127 PM38 1.88E+05 1.25E+02 4.61E+04 4.39E+01
128 PM29 9.59E+04 1.25E+02 2.62E+04 4.39E+01
129 DW03B 5.82E+04 3.07E+02 6.33E+02 1.08E+02
130 PM39 4.49E+04 1.25E+02 3.60E+03 4.39E+01
131 DW04 6.18E+03 1.25E+02 1.83E+02 4.39E+01
132 PM27 6.14E+03 1.25E+02 4.80E+02 4.39E+01
133 PM15 1.88E+03 1.25E+02 2.87E+02 4.39E+01
134 PM11 1.02E+03 1.25E+02 3.95E+01 4.39E+01
135 DF3_4NTan - - - -
136 DW13 - - - -
137 PM128_06 - - - -
135
# Sample name
Total bacteria
concentration in original
sample (copies/mL)
Detection limit
(copies/mL)
Total archaea
concentration in original
sample (copies/mL)
Detection limit
(copies/mL)
138 PM128_11 - - - -
139 PM30 - - - -
140 PM36 - - - -
Legend: Samples with “-“ were not quantified due to low amount of sample left.
(*) 16S rRNA results from this sample were different from other similar samples, which might indicate an error. This sample was not considered in
any of the analysis.
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Figure E.2 qPCR results (copies/mL) for microcosms, soil, groundwater, and pure culture samples. The lower graph is a continuation of the
upper graph for better visualization. The samples are ordinated from highest to lowest number of Bacteria. X axis shows sample names and Y axis
show the concentration of bacteria or archaea in original sample (copies/mL).
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Figure E.3 Relative abundance (%) of microorganisms in anaerobic microcosms samples from site 2B. Compounds tested in each site are
shown on the top of the graph in yellow box and the compound that were biotransformed are shown in the white boxes, if any. Only Bacteria is plotted
in this graph. X axis show samples names and Y axis show relative abundance (%) of each microorganism per sample. This graph shows data
represented in OTU level.
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Table E.5 Most abundant OTUs found in pure and enrichment cultures from external laboratories and tested in UofT. Cells highlighted in
bright yellow are the most dominant taxa in the sample, and light yellow are high abundance organisms that can be also responsible for biodegradation
of the compounds of interest. CB = chlorobenzene, DCB = dichlorobenzene, NT = nitrotoluene, DCNB = dichloronitrobenzene. FBR = fluidized bed
reactor. DF = David Freedman’s samples. J = Jim Spain’s samples.
Sample DF1 DF2 DF3 J1 J5 J3_FBR J7_FBR J8_FBR
Substrate CB 1,2-DCB 4-NT 2,3-DCNB 3,4-DCNB 2,3-DCNB 3,4-DCNB 1,2-DCB
Condition Aerobic Aerobic Anaerobic Aerobic Aerobic Aerobic Aerobic Aerobic
Pelosinus (OTU 43) 0 0 56 0 0 0 0 0
Desulfotomaculum (OTU 89) 0 0 16 0 0 0 0 0
Propionicicella (OTU 108) 0 0 11 0 0 0 0 0
Pandoraea (OTU 10) 77 87 0 0 0 0 0 0
Rhodanobacter (OTU 72) 14 0.013 0 0 0 0 0 0
Diaphorobacter (OTU 09) 0 0 0 76 97 5.5 0.36 0.012
Alcaligenaceae (OTU 11) 0 0 0 2.6 0.004 48 43 0.17
Rhodococcus (OTU 23) 0 0 0 0 0 32 27 8.9
Luteimonas (OTU 51) 0 0 0 6.8 0 5.6 12 0.24
Cupriavidus (OTU 24) 3.4 3.5 0 0 0 0 0 77
Comamonadaceae (OTU 177) 0 0 0 3.8 0 0.61 0.14 1.8
Flavobacterium (OTU 56) 0 0 0 3.8 0 1.0 7.3 7.0
Other OTUs in lower abundances 6 9.6 17 7 3 7 10 5
Total (%) 100 100 100 100 100 100 100 100
139
Figure E.4 Relative abundance (%) of Rhodanobacter (OTU72) in all the samples. X axis represents relative
abundance (%) of organism in log scale, Y axis represents the sample name where the organism was found.
140
Figure E.5 Relative abundance (%) of Pelosinus (OTU43), Desulfotomaculum (OTU89), and Propionicicella (OTU108) in all the
samples. X axis of the graph show relative abundance of organism in log scale, Y axis show the sample name where the organism was found.
141
Figure E.6 Relative abundance (%) of Diaphorobacter (OTU9) in all the samples. X axis of the graph show relative abundance of
organism in log scale, Y axis show the sample name where the organism was found.
142
Figure E.7 Relative abundance (%) of Rhodococcus (OTU23) in all the samples. X axis of the graph show relative
abundance of organism in log scale, Y axis show the sample name where the organism was found.
143
Figure E.8 Relative abundance (%) of Alcaligenaceae (OTU11) in all the samples. X axis of the graph show
relative abundance of organism in log scale, Y axis show the sample name where the organism was found.
144
Figure E.9 Relative abundance (%) of Cupriavidus (OTU24) in all the samples. X axis of the graph show relative
abundance of organism in log scale, Y axis show the sample name where the organism was found.
145
Appendix F. Supplementary information for statistical analyses
R Markdown script used to analyze all the samples in RStudio
#Select the libraries you want to use for your analysis knitr::opts_chunk$set(echo = TRUE) rm(list=ls(all=TRUE)) library(readxl) library(ape) library(ggplot2) library(permute) library(dplyr) library(grid) library(reshape2) library(vegan) library(phyloseq) library(RColorBrewer) library(ampvis2) theme_set(theme_bw()) knitr::opts_chunk$set(echo = TRUE) #Select the directory where your working files are saved setwd("~/Suzana") sharedfile = "Suzana_140samples.0.03.subsample_newnames" #Input file from Mothur taxfile = "Taxonomyfile3.txt" #Text file with all the reads and taxonomy names mapfile = "env_SK.csv" #Excel spreadsheet with environmental data for all the samples mothur_data <- import_mothur(mothur_shared_file = sharedfile, mothur_constaxonomy_file = taxfile) map <- read.csv(mapfile) #To reformat the metadata file so that you can merge it with the phyloseq file mothur_data. In order to merge the files, the row names need to match the sample names. Here the Sample_name column in the metadata file contains the sample names. rownames(map) <- map$Sample_name map <- sample_data(map) moth_merge <- merge_phyloseq(mothur_data, map) #optional - renaming taxonomic levels from rank to something more meaningful colnames(tax_table(moth_merge))
colnames(tax_table(moth_merge)) <- c("Kingdom", "Phylum", "Class", "Order", "Family", "Genus", "Species") moth_merge
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#relative abundance: moth_mergeP <- transform_sample_counts(moth_merge, function(x){100*x/sum(x)}) #Filter out low abundant taxa, more than 5 reads in at least 1% of samples wh0 = genefilter_sample(moth_merge, filterfun_sample(function(x) x > 5), A=0.01*nsamples(moth_merge)) moth_mergeF = prune_taxa(wh0, moth_merge) moth_mergeF
#Creating a subset for microcosms samples only Microcosms <- subset_samples(moth_merge, Matrix=="MC") wh0 = genefilter_sample(Microcosms, filterfun_sample(function(x) x > 5), A=0.01*nsamples(Microcosms)) MicrocosmsF = prune_taxa(wh0, Microcosms) MicrocosmsF
#odinate all the samples together AllSamples_NMDS <- ordinate(moth_mergeF, "NMDS", "bray", k=2)
#ordinate only microcosms samples Microcosms_NMDS <- ordinate(MicrocosmsF, "NMDS", "bray", k=2)
#Plot showing all the samples, coloring samples by matrix. SampleNMDS = plot_ordination(moth_mergeF, AllSamples_NMDS, type="samples", color="Matrix", label="Sample_name", title = "NMDS for all samples") + theme(legend.position = "right", legend.text = element_text(size = 11), legend.key.size = unit(0.5, "cm")) + scale_colour_brewer(palette = "Set1") + geom_hline(aes(yintercept = 0)) + geom_vline(aes(xintercept = 0)) SampleNMDS
#Plot showing all the samples and coloring them by pH. Shapes mean the matrix of each sample. SampleNMDS_MC = plot_ordination(moth_mergeF, AllSamples_NMDS, type="samples", color="pH", shape="Matrix", label="Sample_name", title="NMDS for all samples - pH") + theme(legend.position = "right", legend.text = element_text(size = 10), legend.key.size = unit(0.5, "cm"))+ geom_hline(aes(yintercept = 0)) +geom_vline(aes(xintercept = 0)) + scale_color_gradient(low="blue", high="red") SampleNMDS_MC
#Plot showing all microcosms sample, including aerobic and anaerobic. The elipse has a confidence level of 95% by deafult. SampleNMDS_microcosms = plot_ordination(MicrocosmsF, Microcosms_NMDS, type="samples", color="Condition", title = "NMDS - Aerobic and Anaerobic Microcosms", shape= "Site") + theme(legend.position = "right", legend.text = element_text(size = 10), legend.key.size = unit(0.5, "cm")) + stat_ellipse(aes(fill="Site"), taxa_names(20)) + scale_colour_brewer(palette = "Set1") + geom_hline(aes(yintercept = 0)) +geom_vline(aes(xintercept = 0))
SampleNMDS_microcosms
#Sub setting for aerobic microcosms Aerobic <- subset_samples(moth_merge, Condition=="Aerobic") wh0 = genefilter_sample(Aerobic, filterfun_sample(function(x) x > 5), A=0.01*
147
nsamples(Aerobic)) AF = prune_taxa(wh0, Aerobic) AF
#Sub setting for anaerobic microcosms Anaerobic <- subset_samples(moth_merge, Condition=="Anaerobic") wh0 = genefilter_sample(Anaerobic, filterfun_sample(function(x) x > 5), A=0.01*nsamples(Anaerobic)) ANF = prune_taxa(wh0, Anaerobic) ANF
#Sub setting for microcosms from site 1A (in the environmental file, the categories can not start with number so this why the sites are inverted, so instead of having site 1A, it is named A1 in the script. Same for all 4 sites) A1 <- subset_samples(moth_merge, Site=="A1") wh0 = genefilter_sample(A1, filterfun_sample(function(x) x > 5), A=0.01*nsamples(A1)) Site1AF = prune_taxa(wh0, A1)
#Sub setting for microcosms from site 2A A2 <- subset_samples(moth_merge, Site=="A2") wh0 = genefilter_sample(A2, filterfun_sample(function(x) x > 5), A=0.01*nsamples(A2)) Site2AF = prune_taxa(wh0, A2) Site2AF
#Sub setting for microcosms from site 1B B1 <- subset_samples(moth_merge, Site=="B1") wh0 = genefilter_sample(B1, filterfun_sample(function(x) x > 5), A=0.01*nsamples(B1)) Site1BF = prune_taxa(wh0, B1) Site1BF
#Sub setting for microcosms from site 2B B2 <- subset_samples(moth_merge, Site=="B2") wh0 = genefilter_sample(B2, filterfun_sample(function(x) x > 5), A=0.01*nsamples(B2)) Site2BF = prune_taxa(wh0, B2) Site2BF
#ordinate the aerobic microcosms samples AF_NMDS <- ordinate(AF, "NMDS", "bray", k=2)
#To choose the colors, use the hexadecimal code in this link http://www.sthda.com/english/wiki/colors-in-r #Graph showing the aerobic degradation in the microcosms ASamplesNMDS_deg2 = plot_ordination(AF, AF_NMDS, type="samples", color="Aerobic_Degradation", title = "NMDS samples-Aerobic Degradation in Microcosms", shape="Treatment") + theme(legend.position = "right", legend.text = element_text(size = 10), legend.key.size = unit(0.5, "cm")) + scale_color_manual(values=c("#663300", "#0000FF" , "#6699CC", "#6600CC","#FF6600", "#99CC66", "#006600"
148
, "#FF99CC", "#FF3399", "#999999")) + geom_hline(aes(yintercept = 0)) + geom_vline(aes(xintercept = 0)) ASamplesNMDS_deg2
#Graph showing the aerobic microcosms colored by site. The elipse has a confidence level of 95% by deafult AerobicMicrocosmsSamplesNMDS = plot_ordination(AF, AF_NMDS, type="sample", color="Site", title="NMDS Samples - Aerobic Microcosms", shape="Soil_origin") + theme(legend.position = "right", legend.text = element_text(size = 10), legend.key.size = unit(0.5, "cm"))+ stat_ellipse(aes(fill="Site"), species.names(20)) + scale_colour_brewer(palette = "Set1") + geom_hline(aes(yintercept = 0)) +geom_vline(aes(xintercept = 0))
AerobicMicrocosmsSamplesNMDS
#Adding the OTU data to the plot #First make the OTU table into a dataframe: Aotudata = data.frame(t(otu_table(AF))) #use the envfit function to fitvectors to our OTUs set.seed(152) plot(AF_NMDS, type="p") Afitotu <- envfit(AF_NMDS, Aotudata , permu = 999) plot(Afitotu, p.max=0.001, col = "red")
#you can change the p-value #print out OTU-correlation values Afitotu[["vectors"]]
#Function: select.envfit - Setting r2 cutoff values to display in an ordination.r.select<-0.3 # correlation threshold, see function below #__FUNCTION: select.envfit__# # function (select.envit) filters the resulting list of function (envfit) based on their p values. This allows to display only significant values in the final plot. # just run this select.envfit<-function(fit, r.select){ #needs two sorts of input: fit= result of envfit, r.select= numeric, correlation minimum threshold for (i in 1:length(fit$vectors$r)) { #run for-loop through the entire length of the column r in object fit$vectors$r starting at i=1 if (fit$vectors$r[i]<r.select) { #Check wether r<r.select, i.e. if the correlation is weaker than the threshold value. Change this Parameter for r-based selection fit$vectors$arrows[i,]=NA #If the above statement is TRUE, i.e. r is smaller than r.select, then the coordinates of the vectors are set to NA, so they cannot be displayed i=i+1 #increase the running parameter i from 1 to 2, i.e. check the next value in the column until every value has been checked } #close if-loop } #close for-loop
149
return(fit) #return fit as the result of the function } #close the function # Perform select.envfit on dataset with r cutoff at 0.7 - you can change the r cut of to get more or fewer OTUs added fit2<-select.envfit(Afitotu, r.select=0.7) #Get them plotted nicely to the NMDS plot #add environmental variables, With display="bp", arrows will be drawn. otuarrowmat <- vegan::scores(fit2, display = "bp") # Add labels, make a data.frame otuarrowdf <- data.frame(labels = rownames(otuarrowmat), otuarrowmat) # Define the arrow aesthetic mapping otuarrow_map <- aes(xend = NMDS1, yend = NMDS2, x = 0, y = 0, shape = NULL, color = NULL, label = labels) otulabel_map <- aes(x = 1.3 * NMDS1, y = 1.3 * NMDS2, shape = NULL, color = NULL, label = labels) otuarrowhead = arrow(length = unit(0.02, "npc")) # Plot showing the aerobic microcosms and arrows representing the main OTUs ASamplesNMDS_deg2 + geom_segment(mapping = otuarrow_map, size = .5, data = otuarrowdf, color = "black", arrow = otuarrowhead) + geom_text(mapping = otulabel_map, size = 4, color= "black", data = otuarrowdf) + theme(legend.position = "right", legend.text = element_text(size = 10), legend.key.size = unit(0.5, "cm"))
keepvariables = which(sapply(sample_data(AF), is.numeric)) physeqsd = data.frame(sample_data(AF))[keepvariables] drop <- c( "Nitrite", "T", "Nitrate", "Chloride", "Sulfate") metadatanoMissing = physeqsd[,!(names(physeqsd) %in% drop)] set.seed(123) #not needed unless you want to reproduce a particular set of random numbers plot(AF_NMDS, type="p") efnm <- envfit(AF_NMDS, metadatanoMissing, permu = 999, na.rm = TRUE, p.max=0.001) #this will plot only arrows with a p value eauql to or less than 0.001: plot(efnm, p.max=0.001)
efnm[["vectors"]]
#making the same type of plot in ggplot efnm.df<-as.data.frame(efnm$vectors$arrows*sqrt(efnm$vectors$r)) efnm.df$metadata<-rownames(efnm.df) #plotting only metadata significant pvalues A <- as.list(efnm$vectors) #creating the dataframe
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pvals<-as.data.frame(A$pvals) arrows<-as.data.frame(A$arrows*sqrt(A$r)) Cnm<-cbind(arrows, pvals) #subset Cnmred <-subset(Cnm,pvals<0.002) Cnmred <- cbind(Cnmred, metadatanoMissing = rownames(Cnmred)) # Define the arrow aesthetic mapping arrow_map <- aes(xend = NMDS1, yend = NMDS2, x = 0, y = 0, shape = NULL, color = NULL) label_map <- aes(x = 1.3 * NMDS1, y = 1.3 * NMDS2, shape = NULL, color = NULL, label = metadatanoMissing) arrowhead = arrow(length = unit(0.02, "npc")) AerobicMicrocosmsSamplesNMDS + geom_segment(mapping = arrow_map, size = 1.5, data = Cnmred, color = "gray", arrow = arrowhead) + geom_text(mapping = label_map, size = 4, data = Cnmred)
physeqsd = data.frame(sample_data(AF)) keep <- c( "Degradation_Transformation", "Depth_m", "pH") #you can add more variables that you want to keep metadataSelect = physeqsd[keep] set.seed(123) #not needed unless you want to reproduce a particular set of random numbers plot(AF_NMDS, type="p") efS <- envfit(AF_NMDS, metadataSelect, permu = 999, na.rm = TRUE, p.max=0.001) #this will plot only arrows with a p value eauql to or less than 0.001: plot(efS, p.max=0.001)
efS[["vectors"]] efS[["factors"]] #making the same type of plot in ggplot efS.df<-as.data.frame(efS$vectors$arrows*sqrt(efS$vectors$r)) efS.df$metadata<-rownames(efS.df) #plotting only metadata significant pvalues A <- as.list(efS$vectors) #creating the dataframe pvals<-as.data.frame(A$pvals) arrows<-as.data.frame(A$arrows*sqrt(A$r)) CS<-cbind(arrows, pvals) #subset CSred <-subset(CS,pvals<0.002) CSred <- cbind(CSred, metadataSelect = rownames(CSred)) # Define the arrow aesthetic mapping
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arrow_map <- aes(xend = NMDS1, yend = NMDS2, x = 0, y = 0, shape = NULL, color = NULL) label_map <- aes(x = 1.3 * NMDS1, y = 1.3 * NMDS2, shape = NULL, color = NULL, label = metadataSelect) arrowhead = arrow(length = unit(0.02, "npc"))
AerobicMicrocosmsSamplesNMDS + geom_segment(mapping = arrow_map, size = 1.5, data = CSred, color = "gray", arrow = arrowhead) + geom_text(mapping = label_map, size = 4, data = CSred)
#ordinate anaerobic microcosms in NMDS ANF_NMDS <- ordinate(ANF, "NMDS", "bray",k=2)
#Plot showing the anaerobic samples and what there were degrading ANSamplesNMDS_deg = plot_ordination(ANF, ANF_NMDS, type="samples", color="Anaerobic_Transformation", title = "NMDS samples-Anaerobic Transformation in Microcosms", shape="Treatment") + theme(legend.position = "right", legend.text = element_text(size = 10), legend.key.size = unit(0.5, "cm")) + scale_color_manual(values=c("#9900CC", "#FF3300" , "#339933", "#0000FF", "#999999")) + geom_hline(aes(yintercept = 0)) + geom_vline(aes(xintercept = 0)) ANSamplesNMDS_deg
#Microcosms separated by site and elipses showing 95% confidence ANSamplesNMDS = plot_ordination(ANF, ANF_NMDS, type="sample", color="Site", shape="Soil_origin", title="NMDS Samples - Anaerobic Microcosms") + theme(legend.position = "right", legend.text = element_text(size = 10), legend.key.size = unit(0.5, "cm"))+ stat_ellipse(aes(fill="Site"), taxa_names(20))+scale_colour_brewer(palette = "Set1") + scale_colour_brewer(palette = "Set1") + geom_hline(aes(yintercept = 0)) +geom_vline(aes(xintercept = 0))
ANSamplesNMDS
#Adding only significant metadata #Adding the environmental data to the plot, using only numeric data. keepvariables = which(sapply(sample_data(ANF), is.numeric)) physeqsd = data.frame(sample_data(ANF))[keepvariables] set.seed(123) #not needed unless you want to reproduce a particular set of random numbers plot(ANF_NMDS, type="p") efAN <- envfit(ANF_NMDS, physeqsd , permu = 999, na.rm = TRUE, p.max=0.001)
#this will plot only arrows with a p value equal to or less than 0.001: plot(efAN, p.max=0.001)
efAN[["vectors"]] # This plots the values so we can check if the results look ok
#making the same type of plot in ggplot efAN.df<-as.data.frame(efAN$vectors$arrows*sqrt(efAN$vectors$r)) efAN.df$metadata<-rownames(efAN.df)
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#plotting only metadata significant pvalues AN <- as.list(efAN$vectors) #creating the dataframe pvals<-as.data.frame(AN$pvals) arrows<-as.data.frame(AN$arrows*sqrt(AN$r)) CAN<-cbind(arrows, pvals) #subset CANred<-subset(CAN,pvals<0.002) #I changd the p-cut off - you can change it back to 0.05 if you want less strict cut-off CANred <- cbind(CANred, metadata = rownames(CANred)) # Define the arrow aesthetic mapping arrow_map <- aes(xend = NMDS1, yend = NMDS2, x = 0, y = 0, shape = NULL, color = NULL) label_map <- aes(x = 1.3 * NMDS1, y = 1.3 * NMDS2, shape = NULL, color = NULL, label = metadat)arrowhead = arrow(length = unit(0.02, "npc"))
ANSamplesNMDS + geom_segment(mapping = arrow_map, size = 1.5, data = CANred, color = "gray", arrow = arrowhead) + geom_text(mapping = label_map, size = 4, data = CANred)
#Adding the OTU data to the plot #First make the OTU table into a dataframe: ANotudata = data.frame(t(otu_table(ANF))) #use the envfit function to fitvectors to our OTUs set.seed(152) plot(ANF_NMDS, type="p") ANFotufit <- envfit(ANF_NMDS, ANotudata , permu = 999) plot(ANFotufit, p.max=0.001, col = "red")
#you can change the p-value #print out OTU-correlation values ANFotufit[["vectors"]]
#Function: select.envfit - Setting r2 cutoff values to display in an ordination.r.select<-0.3 # correlation threshold, see function below #__FUNCTION: select.envfit__# # function (select.envit) filters the resulting list of function (envfit) based on their p values. This allows to display only significant values in the final plot. # just run this select.envfit<-function(fit, r.select){ #needs two sorts of input: fit= result of envfit, r.select= numeric, correlation minimum threshold for (i in 1:length(fit$vectors$r)) { #run for-loop through the entire length of the column r in object fit$vectors$r starting at i=1 if (fit$vectors$r[i]<r.select) { #Check wether r<r.select, i.e. if the correlation is weaker than the threshold value. Change this Parameter for r-based selection fit$vectors$arrows[i,]=NA #If the above statement is TRUE, i.e. r is smaller than r.select, then the coordinates of the vectors are set to NA, so they can
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not be displayed i=i+1 #increase the running parameter i from 1 to 2, i.e. check the next value in the column until every value has been checked } #close if-loop } #close for-loop return(fit) #return fit as the result of the function } #close the function # Perform select.envfit on dataset with r cutoff at 0.3 - you can change the r cut of to get more or fewer OTUs added fit3<-select.envfit(ANFotufit, r.select=0.4) #Get them plotted nicely to the NMDS plot #add environmental variables, With display="bp", arrows will be drawn. otuarrowmat <- vegan::scores(fit3, display = "bp") # Add labels, make a data.frame otuarrowdf <- data.frame(labels = rownames(otuarrowmat), otuarrowmat) # Define the arrow aesthetic mapping otuarrow_map <- aes(xend = NMDS1, yend = NMDS2, x = 0, y = 0, shape = NULL, color = NULL, label = labels) otulabel_map <- aes(x = 1.3 * NMDS1, y = 1.3 * NMDS2, shape = NULL, color = NULL, label = labels) otuarrowhead = arrow(length = unit(0.02, "npc")) # Plot showing the aerobic microcosms and arrows representing the main OTUs ANSamplesNMDS_deg + geom_segment(mapping = otuarrow_map, size = .5, data = otuarrowdf, color = "black", arrow = otuarrowhead) + geom_text(mapping = otulabel_map, size = 4, color= "black", data = otuarrowdf) + theme(legend.position = "right", legend.text = element_text(size = 10), legend.key.size = unit(0.5, "cm"))
#ordinate the samples in NMDS by site Site1A_NMDS <- ordinate(Site1AF, "NMDS", "bray",k=2) #Site 1A Site1B_NMDS <- ordinate(Site1BF, "NMDS", "bray",k=2) #Site 1B Site2A_NMDS <- ordinate(Site2AF, "NMDS", "bray",k=2) #Site 2A Site2B_NMDS <- ordinate(Site2BF, "NMDS", "bray",k=2) #Site 2B #NMDS plot for microcosms from site 1A Site1ASamplesNMDS_treat = plot_ordination(Site1AF, Site1A_NMDS, type="samples", shape="Treatment", color="Degradation_Transformation", title = "NMDS - Reactions observed in Microcosms from site 1A") + theme(legend.position = "right", legend.text = element_text(size = 10), legend.key.size = unit(0.5, "cm") ) + scale_color_manual(values=c("#660099", "#FF00CC" , "#0066CC", "#FF0000", "#FF9900", "#999999"))+ geom_hline(aes(yintercept = 0)) +geom_vline(aes(xintercept = 0)) Site1ASamplesNMDS_treat
#NMDS plot for microcosms from site 1B Site1BSamplesNMDS_treat = plot_ordination(Site1BF, Site1B_NMDS, type="samples", shape="Treatment", color="Degradation_Transformation", title = "NMDS - Rea
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ctions observed in Microcosms from site 1B") + theme(legend.position = "right", legend.text = element_text(size = 10), legend.key.size = unit(0.5, "cm") ) + scale_color_manual(values=c("#FF0000", "#999999"))+ geom_hline(aes(yintercept = 0)) +geom_vline(aes(xintercept = 0)) Site1BSamplesNMDS_treat
#NMDS plot for microcosms from site 2A Site2ASamplesNMDS_treat = plot_ordination(Site2AF, Site2A_NMDS, type="samples", shape="Treatment", color="Degradation_Transformation", title = "NMDS - Reactions observed in Microcosms from site 2A") + theme(legend.position = "right", legend.text = element_text(size = 10), legend.key.size = unit(0.5, "cm") ) + scale_color_manual(values=c("#CC00CC", "#3399FF", "#009933", "#CC0033", "#FF6633"))+ geom_hline(aes(yintercept = 0)) +geom_vline(aes(xintercept = 0)) Site2ASamplesNMDS_treat
#NMDS plot for microcosms from site 2B Site2BSamplesNMDS_treat = plot_ordination(Site2BF, Site2B_NMDS, type="samples", shape="Treatment", color="Degradation_Transformation", title = "NMDS - Reactions observed in Microcosms from site 2B") + theme(legend.position = "right", legend.text = element_text(size = 10), legend.key.size = unit(0.5, "cm") ) + scale_color_manual(values=c("#FF66FF", "#3399FF", "#339933", "#CC0033", "#999999"))+ geom_hline(aes(yintercept = 0)) +geom_vline(aes(xintercept = 0)) Site2BSamplesNMDS_treat
#First make the OTU table into a dataframe: Site1AFotudata = data.frame(t(otu_table(Site1AF))) #use the envfit function to fitvectors to our OTUs set.seed(152) plot(Site1A_NMDS, type="p") Site1AFotufit <- envfit(Site1A_NMDS, Site1AFotudata , permu = 999) plot(Site1AFotufit, p.max=0.001, col = "red")
#you can change the p-value #print out OTU-correlation values Site1AFotufit[["vectors"]]
#Function: select.envfit - Setting r2 cutoff values to display in an ordination.r.select<-0.3 # correlation threshold, see function below #__FUNCTION: select.envfit__# # function (select.envit) filters the resulting list of function (envfit) based on their p values. This allows to display only significant values in the final plot. # just run this select.envfit<-function(fit, r.select){ #needs two sorts of input: fit= result of envfit, r.select= numeric, correlation minimum threshold for (i in 1:length(fit$vectors$r)) { #run for-loop through the entire length of the column r in object fit$vectors$r starting at i=1 if (fit$vectors$r[i]<r.select) { #Check wether r<r.select, i.e. if the correlation is weaker than the threshold value. Change this Parameter for r-based selection
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fit$vectors$arrows[i,]=NA #If the above statement is TRUE, i.e. r is smaller than r.select, then the coordinates of the vectors are set to NA, so they cannot be displayed i=i+1 #increase the running parameter i from 1 to 2, i.e. check the next value in the column until every value has been checked } #close if-loop } #close for-loop return(fit) #return fit as the result of the function } #close the function # Perform select.envfit on dataset with r cutoff at 0.3 - you can change the r cut of to get more or fewer OTUs added fit4<-select.envfit(Site1AFotufit, r.select=0.75) #Get them plotted nicely to the NMDS plot #add environmental variables, With display="bp", arrows will be drawn. otuarrowmat <- vegan::scores(fit4, display = "bp") # Add labels, make a data.frame otuarrowdf <- data.frame(labels = rownames(otuarrowmat), otuarrowmat) # Define the arrow aesthetic mapping otuarrow_map <- aes(xend = NMDS1, yend = NMDS2, x = 0, y = 0, shape = NULL, color = NULL, label = labels) otulabel_map <- aes(x = 1.3 * NMDS1, y = 1.3 * NMDS2, shape = NULL, color = NULL, label = labels) otuarrowhead = arrow(length = unit(0.02, "npc")) # Plot showing the aerobic microcosms and arrows representing the main OTUs Site1ASamplesNMDS_treat + geom_segment(mapping = otuarrow_map, size = .5, data = otuarrowdf, color = "black", arrow = otuarrowhead) + geom_text(mapping = otulabel_map, size = 4, color= "black", data = otuarrowdf) + theme(legend.position = "right", legend.text = element_text(size = 10), legend.key.size = unit(0.5, "cm"))
#First make the OTU table into a dataframe: Site1BFotudata = data.frame(t(otu_table(Site1BF))) #use the envfit function to fitvectors to our OTUs set.seed(152) plot(Site1B_NMDS, type="p") Site1BFotufit <- envfit(Site1B_NMDS, Site1BFotudata , permu = 999) plot(Site1BFotufit, p.max=0.001, col = "red")
#you can change the p-value #print out OTU-correlation values Site1BFotufit[["vectors"]]
#Function: select.envfit - Setting r2 cutoff values to display in an ordination.r.select<-0.3 # correlation threshold, see function below
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#__FUNCTION: select.envfit__# # function (select.envit) filters the resulting list of function (envfit) based on their p values. This allows to display only significant values in the final plot. # just run this select.envfit<-function(fit, r.select){ #needs two sorts of input: fit= result of envfit, r.select= numeric, correlation minimum threshold for (i in 1:length(fit$vectors$r)) { #run for-loop through the entire length of the column r in object fit$vectors$r starting at i=1 if (fit$vectors$r[i]<r.select) { #Check wether r<r.select, i.e. if the correlation is weaker than the threshold value. Change this Parameter for r-based selection fit$vectors$arrows[i,]=NA #If the above statement is TRUE, i.e. r is smaller than r.select, then the coordinates of the vectors are set to NA, so they cannot be displayed i=i+1 #increase the running parameter i from 1 to 2, i.e. check the next value in the column until every value has been checked } #close if-loop } #close for-loop return(fit) #return fit as the result of the function } #close the function # Perform select.envfit on dataset with r cutoff at 0.3 - you can change the r cut of to get more or fewer OTUs added fit5<-select.envfit(Site1BFotufit, r.select=0.75) #Get them plotted nicely to the NMDS plot #add environmental variables, With display="bp", arrows will be drawn. otuarrowmat <- vegan::scores(fit5, display = "bp") # Add labels, make a data.frame otuarrowdf <- data.frame(labels = rownames(otuarrowmat), otuarrowmat) # Define the arrow aesthetic mapping otuarrow_map <- aes(xend = NMDS1, yend = NMDS2, x = 0, y = 0, shape = NULL, color = NULL, label = labels) otulabel_map <- aes(x = 1.3 * NMDS1, y = 1.3 * NMDS2, shape = NULL, color = NULL, label = labels) otuarrowhead = arrow(length = unit(0.02, "npc")) # Plot showing the aerobic microcosms and arrows representing the main OTUs Site1BSamplesNMDS_treat + geom_segment(mapping = otuarrow_map, size = .5, data = otuarrowdf, color = "black", arrow = otuarrowhead) + geom_text(mapping = otulabel_map, size = 4, color= "black", data = otuarrowdf) + theme(legend.position = "right", legend.text = element_text(size = 10), legend.key.size = unit(0.5, "cm"))
#First make the OTU table into a dataframe: Site2AFotudata = data.frame(t(otu_table(Site2AF))) #use the envfit function to fitvectors to our OTUs
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set.seed(152) plot(Site2A_NMDS, type="p") Site2AFotufit <- envfit(Site2A_NMDS, Site2AFotudata , permu = 999) plot(Site2AFotufit, p.max=0.001, col = "red")
#you can change the p-value #print out OTU-correlation values Site2AFotufit[["vectors"]]
#Function: select.envfit - Setting r2 cutoff values to display in an ordination.r.select<-0.3 # correlation threshold, see function below #__FUNCTION: select.envfit__# # function (select.envit) filters the resulting list of function (envfit) based on their p values. This allows to display only significant values in the final plot. # just run this select.envfit<-function(fit, r.select){ #needs two sorts of input: fit= result of envfit, r.select= numeric, correlation minimum threshold for (i in 1:length(fit$vectors$r)) { #run for-loop through the entire length of the column r in object fit$vectors$r starting at i=1 if (fit$vectors$r[i]<r.select) { #Check wether r<r.select, i.e. if the correlation is weaker than the threshold value. Change this Parameter for r-based selection fit$vectors$arrows[i,]=NA #If the above statement is TRUE, i.e. r is smaller than r.select, then the coordinates of the vectors are set to NA, so they cannot be displayed i=i+1 #increase the running parameter i from 1 to 2, i.e. check the next value in the column until every value has been checked } #close if-loop } #close for-loop return(fit) #return fit as the result of the function } #close the function # Perform select.envfit on dataset with r cutoff at 0.3 - you can change the r cut of to get more or fewer OTUs added fit6<-select.envfit(Site2AFotufit, r.select=0.6) #Get them plotted nicely to the NMDS plot #add environmental variables, With display="bp", arrows will be drawn. otuarrowmat <- vegan::scores(fit6, display = "bp") # Add labels, make a data.frame otuarrowdf <- data.frame(labels = rownames(otuarrowmat), otuarrowmat) # Define the arrow aesthetic mapping otuarrow_map <- aes(xend = NMDS1, yend = NMDS2, x = 0, y = 0, shape = NULL, color = NULL, label = labels) otulabel_map <- aes(x = 1.3 * NMDS1, y = 1.3 * NMDS2, shape = NULL, color = NULL, label = labels) otuarrowhead = arrow(length = unit(0.02, "npc"))
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# Plot showing the aerobic microcosms and arrows representing the main OTUs Site2ASamplesNMDS_treat + geom_segment(mapping = otuarrow_map, size = .5, data = otuarrowdf, color = "black", arrow = otuarrowhead) + geom_text(mapping = otulabel_map, size = 4, color= "black", data = otuarrowdf) + theme(legend.position = "right", legend.text = element_text(size = 10), legend.key.size = unit(0.5, "cm"))
#First make the OTU table into a dataframe: Site2BFotudata = data.frame(t(otu_table(Site2BF))) #use the envfit function to fitvectors to our OTUs set.seed(152) plot(Site2B_NMDS, type="p") Site2BFotufit <- envfit(Site2B_NMDS, Site2BFotudata , permu = 999) plot(Site2BFotufit, p.max=0.001, col = "red")
#you can change the p-value #print out OTU-correlation values Site2BFotufit[["vectors"]]
#Function: select.envfit - Setting r2 cutoff values to display in an ordination.r.select<-0.3 # correlation threshold, see function below #__FUNCTION: select.envfit__# # function (select.envit) filters the resulting list of function (envfit) based on their p values. This allows to display only significant values in the final plot. # just run this select.envfit<-function(fit, r.select){ #needs two sorts of input: fit= result of envfit, r.select= numeric, correlation minimum threshold for (i in 1:length(fit$vectors$r)) { #run for-loop through the entire length of the column r in object fit$vectors$r starting at i=1 if (fit$vectors$r[i]<r.select) { #Check wether r<r.select, i.e. if the correlation is weaker than the threshold value. Change this Parameter for r-based selection fit$vectors$arrows[i,]=NA #If the above statement is TRUE, i.e. r is smaller than r.select, then the coordinates of the vectors are set to NA, so they cannot be displayed i=i+1 #increase the running parameter i from 1 to 2, i.e. check the next value in the column until every value has been checked } #close if-loop } #close for-loop return(fit) #return fit as the result of the function } #close the function # Perform select.envfit on dataset with r cutoff at 0.3 - you can change the r cut of to get more or fewer OTUs added fit7<-select.envfit(Site2BFotufit, r.select=0.8) #Get them plotted nicely to the NMDS plot #add environmental variables, With display="bp", arrows will be drawn.
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otuarrowmat <- vegan::scores(fit7, display = "bp") # Add labels, make a data.frame otuarrowdf <- data.frame(labels = rownames(otuarrowmat), otuarrowmat) # Define the arrow aesthetic mapping otuarrow_map <- aes(xend = NMDS1, yend = NMDS2, x = 0, y = 0, shape = NULL, color = NULL, label = labels) otulabel_map <- aes(x = 1.3 * NMDS1, y = 1.3 * NMDS2, shape = NULL, color = NULL, label = labels) otuarrowhead = arrow(length = unit(0.02, "npc")) # Plot showing the aerobic microcosms and arrows representing the main OTUs Site2BSamplesNMDS_treat + geom_segment(mapping = otuarrow_map, size = .5, data = otuarrowdf, color = "black", arrow = otuarrowhead) + geom_text(mapping = otulabel_map, size = 4, color= "black", data = otuarrowdf) + theme(legend.position = "right", legend.text = element_text(size = 10), legend.key.size = unit(0.5, "cm"))
Making relative abundance files, and a file with low abundant taxa filtered out and plotting
a bar chart
#Load the libraries you need library(dendextend) library(ape) library(cowplot) library(tidyverse) #Sub setting groundwater samples from full metadata table Groundwater <- subset_samples(moth_merge, Matrix=="GW") wh0 = genefilter_sample(Groundwater, filterfun_sample(function(x) x > 5), A=0.01*nsamples(Groundwater)) GWF = prune_taxa(wh0, Groundwater) GWF
#relative abundance: GroundwaterP <- transform_sample_counts(Groundwater, function(x){100*x/sum(x)}) #1% in at least 1 sample require("genefilter") flist <- filterfun(kOverA(1, 1)) Groundwater1PS = filter_taxa(GroundwaterP, flist, TRUE) #making a genus color palette. "Paired" is a palette from RColorBrewer getPalette = colorRampPalette(brewer.pal(12, "Paired")) GenusList = unique(tax_table(Groundwater1PS)[,"Genus"]) GenusPalette = getPalette(length(GenusList)) GWFdist = distance(GWF, "jsd", type = "samples") GWF.hclust <- hclust(GWFdist, method = "average")
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#Dendrogram for groundwater samples dend = as.dendrogram(GWF.hclust) dend <- set(dend, "labels_cex", 0.6) p1 <- ggplot(dend, horiz = T) p1
#Bar chart showing relative abundance (%) in groundwater samples without legend p2 = plot_bar(Groundwater1PS, "Sample", fill="Genus")+ geom_bar(aes(x=Sample_name, fill=Genus, position = "fill"), stat="identity", position="stack") + theme(axis.text.x = element_text(size = 8), axis.text.y = element_text(size = 8)) + theme(text = element_text(size = 8), legend.position = "none") + scale_fill_manual(values= GenusPalette) + coord_flip()
p2$data$Sample <- factor(p2$data$Sample,levels= labels(dend)) p2
#Dendrogram and bar chart aligned plot_grid(p1, p2, align = "h", axis ="r", label_fontface = plain, label_size=2)
#Bar chart of groundwater samples with legend p3=plot_bar(Groundwater1PS, "Sample", fill="Genus") + geom_bar(aes(x=Sample_name, fill=Genus, position = "fill"), stat="identity", position="stack") + theme(axis.text.x = element_text(size = 8), axis.text.y = element_text(size = 8)) + theme(text = element_text(size = 8), legend.position = "bottom", legend.text = element_text(size = 3), legend.key.size = unit(0.1, "cm")) + scale_fill_manual(values= GenusPalette)
p3$data$Sample <- factor(p3$data$Sample,levels= labels(dend)) p3
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Appendix G. Electronic files available as supplementary data
The following documents were used during this research and are available online, in Syntrophy
folder, in OwnCloud. The folder location is Syntrophy/People/Students/Current/Suzana Kraus
2016/MASC Thesis additional data files.
Name of the file Type of file Content
Aerobic and anaerobic
degradation graphs
Excel spreadsheet Aerobic and anaerobic
microcosms degradation graphs
Raw results MetaAmp Excel spreadsheet Raw results generated by
MetaAmp
Metadata table Excel spreadsheet Metadata table used as input in
RStudio
Sequencing results bar
charts
Excel spreadsheet Amplicon sequencing results
processed. This file also contains
the bar charts.
qPCR results Excel spreadsheet qPCR raw results for all samples