Post on 24-Feb-2018
Wed Oct 26, 2016 – Track 3
Dries Vandamme, PhDVisiting Researcher UNSW Sydney AustraliaKU Leuven - BelgiumMolecular and Microbial SystemsLaboratory for Aquatic BiologyDries.vandamme@kuleuven.be
Mixotropic growth of microalgae revisited
opportunities and challenges
Outline
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• Growth modes => cultivation strategy• Species• Hetero- and Mixotrophy: advantages• Limitation and opportunities
o Carbon sourceo Contaminationo Bioreactorso Harvestingo Composition and products
• Conclusions
Growth modes of microalgae cultivation
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Growth mode Energy source
Carbon source
Light requirement
metabolism
Photo-autotrophic Light Inorganic Obligatory no switchHeterotrophic Organic Organic - switchPhotoheterotrophic Light Organic Obligatory switchMixotrophic Light and
organicInorganicand organic
Not Obligatory Simultaneousutilization
Benemann J ABBB 2016
Cultivation strategies: single stage vs sequential
Species dependency
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Growth mode SpeciesPhoto-autotrophic Most species are obligate autotrophsHeterotrophic Amphora, Ankistrodesmus, Chlamydomonas,
Chlorella, Chlorococcum, Crypthecodinium, Cyclotella, Dunaliella, Euglena, Nannochloropsis, Nitzschia, Ochromonas, and Tetraselmis
Mixotrophic Brachiomonas submarina , Chlorella spp., Chlorococcum sp ., Cyclotella cryptica , Euglena gracilis , Haematococcus pluvialis , Nannochloropsisspp ., Navicula saprophila , Nitzschia sp., Ochromonas minima, Phaeodactylum tricornutum , Rhodomonas reticulate and Scenedesmus obliquus Anabaena , Spirulina and Synechococcus
Advantages
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Heterotrophic MixotrophicHigher growth rates and biomass density
Higher growth rates by shortening growth cycles
Higher total lipid content per dry cell weight
Prolonged exponential phase
Higher biomass productivity Reduction of biomass loss from respiration during dark hours
Wastewater remediation: DOC, N, P removal
Reduction of photo-inhibitory effect
Flexibility of cultivation regime
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Babaei et al. 2016
C. vulgaris
Limitations and opportunities
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LimitationsCost for carbon sourceCompetition by fast-growing bacteriaBioreactor implementation/OPEXDownstream processing costs
Opportunities?
Carbon source
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• Glucose• Carboxylic
acids• Alcohols
Perez-Garcia & Bashan 2014
Carbon source
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opportunitiesCheap (waste) organic carbon sourcesStrain bio-prospectionMetabolic engineeringImprove lignocellulosic degradation
Lowrey et al. 2015
Contamination/competition
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opportunitiesMixotrophic cultivation strategiesEstablish cultures in bacteria adverse conditionsBioprospection of fast growing strainsCofactor symbiosis
Deschênes et al. 2016
• Fast growing microorganismso Competition with
microalgaeo Alternate/simultaneous feed
N/glucose
Contamination/competition
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• symbiosis o E. coli's provision of
thiamine derivatives and degradation products
o A. protothecoides growth stimulation, lipid content, glucose uptake
opportunitiesMixotrophic cultivation strategiesEstablish cultures in bacteria adverse conditionsBioprospection of fast growing strainsCofactor symbiosis
Higgins et al. 2016
• Fast growing microorganismso Competition with
microalgae
Bioreactors
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• Oswald et al. (1950s) HRAPopportunitiesCheaper materialsImplementation of renewable energy resourcesNon axenic open pond systemsRA of GMO in large scale facilities
Technical aspect Photo-auto Hetero MixoBioreactor type Photobioreactor
(open/closed)Fermenters Photo-bioreactor
(open/closed)Surface to volume ratio
high low high
Sterility Usually sanitized Sterility required Sterility preferredContamination risk medium high medium
Harvesting using bioflocculation
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opportunitiesExopolysaccharides => bioflocculationImmobilisation strategiesBioflocculation signaling molecules
Alam, M.A., Vandamme, D., Chun, W. et al. Rev Environ Sci Biotechnol (2016). doi:10.1007/s11157-016-9408-8
• Settling Micractinium Benemann et al. 1980
Composition and products
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Compound (%) Photo-autotrophic
Heterotrophic Mixotrophic
Protein 29-60 10-40 32-40Carbohydrates 10-20 15-45 10-30Lipids (total) 3-28 25-60 11-58
Prokop et al. 2015
Composition and products
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Fraction Compound Auto hetero mixoLipids TAG medium high high
isoprenoids medium high mediumOmega-3 FA high medium highhydrocarbons medium high medium
Carbohydrates Starch/glycogen low high lowProteins soluble high low high
insoluble high low mediumPigments chlorophylls high low medium
B-carotene high low mediumLutein medium high highAstaxanthin medium high high
Conclusions
• R&D should focus on:
o Lowering cost of carbon substrateso Bio-prospecting and metabolically engineeringo Determining the potential of consortia in natural co-cultivationo Design of suitable bioreactors in cheap materialso Optimizing downstream processing
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Key referencesAndrade, M.R., Costa, J.A. V, 2007. Mixotrophic cultivation of microalga Spirulina platensis using molasses as organic substrate. Aquaculture 264, 130–134. doi:10.1016/j.aquaculture.2006.11.021
Babaei, A., Mehrnia, M.R., Shayegan, J., Sarrafzadeh, M.H., 2016. Comparison of different trophic cultivations in microalgal membrane bioreactor containing N-riched wastewater forsimultaneous nutrient removal and biomass production. Process Biochemistry 51, 1568–1575. doi:10.1016/j.procbio.2016.06.011
Ceron Garcia, M.C., Garcia Camacho, F., Sanchez Miron, A., Fernandez Sevilla, J.M., Chisti, Y., Molina Grima, E., 2006. Mixotrophic production of marine microalga Phaeodactylumtricornutum on various carbon sources. Journal of Microbiology and Biotechnology 16, 689–694.
Chaiprapat, S., Sasibunyarat, T., Charnnok, B., Cheirsilp, B., 2016. Intensifying Clean Energy Production Through Cultivating Mixotrophic Microalgae from Digestates of Biogas Systems: Effects of Light Intensity, Medium Dilution, and Cultivating Time. BioEnergy Research. doi:10.1007/s12155-016-9780-9
Chojnacka, K., Noworyta, A., 2004. Evaluation of Spirulina sp. growth in photoautotrophic, heterotrophic and mixotrophic cultures. Enzyme and Microbial Technology 34, 461–465. doi:10.1016/j.enzmictec.2003.12.002
Deschênes, J.S., Boudreau, A., Tremblay, R., 2015. Mixotrophic production of microalgae in pilot-scale photobioreactors: Practicability and process considerations. Algal Research 10, 80–86. doi:10.1016/j.algal.2015.04.015
Deschênes, J.-S., 2016. A Bacteriostatic Control Approach for Mixotrophic Cultures of Microalgae. IFAC-PapersOnLine 49, 1074–1078. doi:10.1016/j.ifacol.2016.07.345
Higgins, B.T., Gennity, I., Samra, S., Kind, T., Fiehn, O., VanderGheynst, J.S., 2016. Cofactor symbiosis for enhanced algal growth, biofuel production, and wastewater treatment. AlgalResearch 17, 308–315. doi:10.1016/j.algal.2016.05.024
Kandimalla, P., Desi, S., Vurimindi, H., 2016. Mixotrophic cultivation of microalgae using industrial flue gases for biodiesel production. Environmental Science and Pollution Research 23, 9345–9354. doi:10.1007/s11356-015-5264-2
Kim, B., Praveenkumar, R., Lee, J., Nam, B., Kim, D.M., Lee, K., Lee, Y.C., Oh, Y.K., 2016. Magnesium aminoclay enhances lipid production of mixotrophic Chlorella sp. KR-1 whilereducing bacterial populations. Bioresource Technology 219, 608–613. doi:10.1016/j.biortech.2016.08.034
Lee, Y.K., 2001. Microalgal mass culture systems and methods: Their limitation and potential. Journal of applied phycology 13, 307–315.
Lowrey, J., Brooks, M.S., McGinn, P.J., 2015. Heterotrophic and mixotrophic cultivation of microalgae for biodiesel production in agricultural wastewaters and associatedchallenges???a critical review. Journal of Applied Phycology 27, 1485–1498. doi:10.1007/s10811-014-0459-3
Mahapatra, D.M., Chanakya, H.N., Ramachandra, T. V., 2014. Bioremediation and lipid synthesis through mixotrophic algal consortia in municipal wastewater. Bioresource Technology 168, 142–150. doi:10.1016/j.biortech.2014.03.130
Perez-garcia, O., Bashan, Y., 2014. Algal Biorefineries. Springer Netherlands, Dordrecht. doi:10.1007/978-94-007-7494-0
Perez-Garcia, O., Escalante, F.M.E., De-Bashan, L.E., Bashan, Y., 2011. Heterotrophic cultures of microalgae: metabolism and potential products. Water research 45, 11–36. doi:10.1016/j.watres.2010.08.037
Prokop, A., Bajpai, R.K., Zappi, M.E., 2015. Algal biorefineries: Volume 2: Products and refinery design, Algal Biorefineries: Volume 2: Products and Refinery Design. doi:10.1007/978-3-319-20200-6
Subramanian, G., Yadav, G., Sen, R., 2016. RSC Advances Rationally leveraging mixotrophic growth of microalgae in di ff erent photobioreactor con fi gurations for reducing the carbon footprint of an algal biore fi nery : a techno-economic perspective. RSC Advances 72897–72904. doi:10.1039/C6RA14611B
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Wed Oct 26, 2016 – Track 3
Dries Vandamme, PhDDries.vandamme@kuleuven.be
Follow me on twitter: @DriesVandamme
Mixotropic growth of microalgae revisited
opportunities and challenges