Cyanobacteria have already been engineered to produce a number of different biofuel related compounds (Machado and Atsumi, 2012). Previous efforts have focused on producing ethanol (Deng and Coleman, 1999), isobutanol (Atsumi et al., 2009), and isobutyraldehyde (Atsumi et al., 2009). These successes clearly demonstrate the malleability of cyanobacteria as a chemical production platform. Over the past 15 years we have moved from detection of the first industrial chemicals produced from exogenous genes in cyanobacteria, through a burst of discovery and experimentation with pathways and design in photosynthetic prokaryotes, to our current status of balancing and matching of production to the metabolism of the host (Oliver et al., 2013). Sustainable biofuel production in cyanobacteria can be fully realized as we focus on pathway engineering and strain development.

Genetically engineered microalgae are nearing commercial release for biofuel production without sufficient public information or ecological studies to investigate their possible risks. Cyanobacteria and eukaryotic green algae are likely to disperse widely from open ponds and, on a smaller scale with a lower probability, from enclosed photobioreactors. With powerful molecular techniques, thousands of algal strains have been screened, hybridized, and redesigned to grow quickly and tolerate extreme conditions. Some biologists do not expect genetically engineered microalgae to survive in the wild. However, thorough ecological and evolutionary assessments are needed to test this assumption and, if the algae do survive, to confirm that their persistence is highly unlikely to cause environmental harm.

to abiotic stresses, such as drought, extreme temperature or salinity, and biotic stresses, such as insects and pathogens, that would normally prove detrimental to plant growth or survival. The technology can also be used to improve the nutritional content of the plant, an application that could be of particular use in the developing world. New-generation GM crops are now also being developed for the production of recombinant medicines and industrial products, such as monoclonal antibodies, vaccines, plastics and biofuels.

An important example of the potential of this technology is the ‘Golden Rice Project’. It is estimated that 72 g of dry Golden Rice will provide 50% of the RDA of vitamin A for a 1–3-year-old Child. Vitamin A deficiency is widespread in the developing world and golden rice is an impressive example of a health solution that can be offered by plant biotechnology.

 

 

Crop yields worldwide are significantly reduced by the action of pathogens, parasites and herbivorous insects. Two examples of commercial GM crop growth in this area are the insect-resistant crops expressing the bt gene (from the bacterium Bacillus thuringiensis) and virus-resistant GM papaya. The first of these has been particularly successful; in the USA, for example, insect resistant GM maize is grown over an area of 10.6 million hectares and comprises 35% of all maize (GM and non-GM) grown in the country. At the laboratory level, resistance has also been engineered to bacterial and fungal plant pathogens

 

Despite the widespread adoption of GE crops, no GE animal has been approved for food consumption in any country. Pharmaceutical drugs produced by GE animals have received regulatory approval; however, the commercial approval of a GE food animal has yet to be accomplished. The first and currently only GE food animal up for approval, the fast-growing AquAdvantage salmon, has been undergoing regulatory review in the USA for over a decade. All regulatory studies, including food safety evaluations, were completed in 2009 at a cost of over $60 million.  In 2010 the FDA determined that the “AquAdvantage Salmon is as safe as food from conventional Atlantic salmon” and that “no significant food safety hazards or risks have been identified with respect to the phenotype of the AquAdvantage Salmon”.  Despite these findings and the proposed production of infertile triploid, all-female fish in contained inland tank systems to prevent escapement, no statement has yet been issued by the FDA regarding approval or otherwise of this first GE food animal.

 

Part of the reason for this protracted regulatory evaluation of the AquAdvantage salmon has been pressure from special interest groups and a handful of elected officials to prevent the product coming to market. Some activist groups have even begun actively targeting supermarket chains to boycott the GE salmon by threatening to cease purchasing at those chains unless they cede to their demands. The on-going regulatory uncertainty has had a pervasive chilling effect upon the development and commercial adoption of GE animals.  Regulatory inaction has the consequence of threatening not only the AquAdvantage salmon, but animal biotechnology in general. Although some might argue that this is a desirable outcome, it is not in society’s interest to give up on a promising set of technologies when science has consistently shown that there is nothing uniquely or inherently risky about food produced from GE animals or crops.

Deng, M.-D., and Coleman, J. R. (1999). Ethanol synthesis by genetic engineering in cyanobacteria. Appl. Environ. Microbiol. 65, 523–528.

Eenennaam A. 2013. GM animals: Why do we need them, what is in the pipeline, and what are the risks? < http://takingstock.asas.org/?p=9537>
Key S, Ma J, Drake P. 2008. Genetically modified plants and human health. J R Soc Med. 101: 290–298. DOI 10.1258/jrsm.2008.070372
Machado, I. M., and Atsumi, S. (2012). Cyanobacterial biofuel production. J. Biotechnol. 162, 50–56. doi:10. 1016/j.jbiotec.2012.03.005

Nozzi N, Oliver J Atsumi S. 2013. Cyanobacteria as a platform for biofuel production. Frontiers in bioengineering and biotechnology. Vol 1: 7 doi: 10.3389/fbioe.2013.00007
Oliver, J. W. K., Machado, I. M. P., Yoneda, H., and Atsumi, S. (2013). Cyanobacterial conversion of carbon dioxide to 2,3- butanediol. Proc. Natl. Acad. Sci. U.S.A. 110, 1249–1254. doi:10.1073/pnas.1213024110

Snow A. and Smith V. 2012. Genetically engineered algae: A key role for ecologist. BioScience. Vol. 62:8; 765-768

 

Cyanobacteria have already been engineered to produce a number of different biofuel related compounds (Machado and Atsumi, 2012). Previous efforts have focused on producing ethanol (Deng and Coleman, 1999), isobutanol (Atsumi et al., 2009), and isobutyraldehyde (Atsumi et al., 2009). These successes clearly demonstrate the malleability of cyanobacteria as a chemical production platform. Over the past 15 years we have moved from detection of the first industrial chemicals produced from exogenous genes in cyanobacteria, through a burst of discovery and experimentation with pathways and design in photosynthetic prokaryotes, to our current status of balancing and matching of production to the metabolism of the host (Oliver et al., 2013). Sustainable biofuel production in cyanobacteria can be fully realized as we focus on pathway engineering and strain development.