Genetically Modified Organisms for Bulk Chemical ProductionLeo van Overbeek
Outline presentation
Introduction Risk evaluations ‘White’ and ‘Green’ biotechnology for bulk
chemical production Bulk chemical production in the future Conclusions
Background
Research at Plant Research International, Wageningen Construction of
genetically modified plants: disease suppression, qualitative aspects, optimization (marker-free GM plants)
GMO acceptance (reports, discussions)
Soil biology (GMO impact analysis)
Introduction
Bulk chemical production E.g. Polyhydroxyalkanoate (PHA)
Production by making use of Genetically Modified Organisms (GMOs) Optimal yield Chemical modification
‘White’ Biotechnology (contained use) and ‘Green’ Biotechnology (GM plants in open fields)
Goal
Overview of prospects and limitations in the application of GMOs for bulk chemical production
Emphasis on ‘White’ Biotechnology Effects on nature and food chains Knowledge gaps for future (large quantity)
production
Risk evaluation and public perception
Release of GMO will always occur What are the events after GMO release
In order of severity: 1. Effect (neutral)2. Hazard (negative consequence)3. Risk (impact)
Risk assessment: Risk = chance of hazard x exposure (volume/ time)
Public perception on modern biotechnology (occasionally no rational arguments used in discussions)
Non-rational arguments
Field experiment with a GM potato line
Aimed to establish possible effects on the indigenous soil and plant-associated microflora
Field destroyed by activists
From literature
Field release studies with GM bacteria and plants
GM plants and micro-organisms are constructed to demonstrate an effect (worst case) No effects observed Or only transient effects observed
No obvious hazards could be find in literature!
Use of GMOs for bulk chemical production Effect on food chains
PHA is non-toxic and non-allergenic Effects on natural environments
PHA is biodegradable
No impact on consumption goods and natural environments expected!
GMO effect after release Effect Measure
Recombinant gene expression Controlled regulation of recombinant gene construct
GMO survival and spread Physiologically impaired host (e.g. auxotrophic strains)Containment genes
Gene transfer Recombinant DNA insertion in non-mobile constructs
Gene type 1) Genes whose products do not have obvious effects on other organisms
2) Assessment for genes whose products have an effect
Limitations to evaluate consequences of GMO releases
Analytical tools Technical limitations for
detection Environmental impact
Where to compare with? Natural fluctuations are
large and not always understood
Ecology Not all organisms are
described (soil) Not all interactions are
clear
-0.8 0.8
-0.6
0.8
YWYW
YW
YDYD
YD
FW
FW
FW
FD
FD
FD
SW
SW
SW
SD
SD
SD
wildtype
transgenic
young
flowering
senescent
Universal DGGE
‘White’ Biotechnology
Contained use of micro-organisms (or biotechnological derivatives) for production of e.g. enzymes and bulk chemicals
Use of renewable raw materials and advanced enzyme systems, replacing fossil raw materials bio-energy biomaterials bulk chemicals
Direct: e.g. bulk chemicals like PHA Indirect: production of enzymes required for bulk
chemical production Realistic for industry
PHA production in closed systems
Construct Reference
Ralstonia eutropha with phaC from Aeromonas punctata
Fukui and Doi 1997 and 1998.
Aeromonas hydrophila with yafH from E. coli
Lu et al., 2004
A. Hydrophila with phaPCJ genes from A. punctata
Han et al., 2004
Arxula adeninivorans with phbABC genes from R. eutropha
Terentiev et al., 2004
Recommendations for ‘white’ biotechnology Microbial host
Suitable for optimization (growth properties, nutrient requirements)
Containment (loss of viability after release) Recombinant gene
Possibilities for modification of the product Control on gene regulation Containment genes (killing of host after accidental
release) Waste
Other applications Eradication of living GMOs in waste products
‘Green’ Biotechnology
Genetically modified plants in fields Open production facilities
Possibility of free exchange of GM materials with the environment and food chains
Coexistence between agricultural systems (controversy organic – conventional farming)
Lower emphasis for industry
PHA production by plants
Construct Reference
Flax (Linum usitatissimum) with phbABC genes from R. eutropha
Wróbel et al., 2004
Tobacco (Nicotiana tabacum) with phbABC genes from R. eutropha
Arai et al., 2004
Requirements for ‘Green’ biotechnology
Plant host Choice of best performing crops for bulk
chemical production Preference for non-food crops
Recombinant gene Marker-free constructs Restrictions on sexual exchange of rec DNA (e.g.
plastid transformation) Logistics to keep GMO seeds separated
from non-GMO seeds
Seed logistics
White Biotechnology
(contained use of GM micro-
Organisms)
Green Biotechnology
(Growth of GM plants
in open fields)
Other applications
(viability of GMO)
wasteCrop wastes
(GMO still viable)
Waste after processing
(nonviable GMO material)
Bulk chemical production
Application of GM microbes for bulk chemical production under contained conditions is realistic Safe production Containment guaranteed
Applications of GM plants in open fields is uncertain and thus less realistic Containment in open fields is difficult to maintain Post harvest measures are required (transport,
storage, raw material treatments)
Prospects
‘White’ biotechnology will become important for bulk chemical production
Production with GM micro-organisms in closed reactors will largely increase
Risk assessment must be adapted for larger-scale production facilities
Processing of fermentation waste products will become important
time
White BiotechnologyExpected scale enlargement
Environmental-friendly production
Adaptations:
Production facilities
Biological containment
Wastes
Consequences
Increased biotechnological production means: Less chemicals and energy required Less toxic wastes produced More emphasis on containment
Infrastructure (input raw materials, processing) Biological containment (facilities and constructs)
Increased organic waste from reactors Concern for living GMOs in products made out of
waste
Solutions
Technical improvement of production facilities, circumstances and GMO constructs
Alternative use of waste from fermentation reactors Agricultural use; e.g. by composting and heat
inactivation or recycling of waste compounds
Conclusions
Only temporal effects have been observed in small-scale GMO release studies
GM constructs for bulk chemical production must be qualified as ‘low in risk’
No effect can be expected with the application of GM microbes for bulk chemical production in ‘white’ biotechnology
Uncertainties exist with increased scale and long-term production with GM plants
Waste products from fermentation reactors must be processed and free of living GMOs
Knowledge gaps
Present analytical tools may be too limited to detect effects by increased-scale and long-term production; special emphasis on GM plant production
Ecological baseline knowledge to discriminate GMO from non-GMO effects
Relevant information on ecological interactions between species (e.g. what can be the effect of elevated levels of PHA on different populations)
Top Related