Monday, 20 August 2012

Genetically engineered algae: adding caution to the optimism

Over the past several years, researchers have been hard at work modifying algae so that they will generate products that are useful to humans--including food, plastics, and pharmaceuticals. There are high hopes that algae can also be "redesigned" to produce biofuels--an attractive idea given the increasing desire to reduce our dependence on fossil fuels. As pointed out in a BioScience Forum essay by Allison Snow and Val Smith, the technique offering "the greatest freedom to improve on the performance of wild strains" is the use of recombinant DNA in a "mass cultivation" setting. In other words, researchers create novel genetic sequences in a laboratory setting, introduce them into algae, and then cultivate the organisms in tanks or pools to investigate the resulting phenotype. Similar methods have been used, with great success, to generate many of the foods we eat and the medicines we take.

Accordingly, Snow and Smith acknowledge the many potential benefits of genetically engineered biofuel algae. At the same time, they also advise caution: Should modified algae escape from cultivation and enter the wider ecosystem, they have the potential to disrupt natural processes; this is especially true if these organisms are engineered to grow faster, out-compete other species, and/or persist in extreme environments. We humans have a troubled history with invasive species--rats, feral house cats, domesticated livestock, exotic plants and insects, and so on--and have learned the hard way how much damage they can cause to ecosystem health and function. Thus, before genetically modified algae are introduced into the environment, the authors strongly suggest that researchers thoroughly investigate biosafety issues.

(An algal bloom. Image courtesy of MDP.)

The organisms in question can be referred to as microalgae, a group that includes both prokaryotic cyanobacteria (i.e., blue-green algae) and eukaryotic algae (including Nannochloropsis and Chlamydomonas). Such species are responsible for algal blooms, which can lead to the die-off of aquatic plants and animals, and the production of toxins that can cause human sickness or death. Although Snow and Smith don't necessarily think that such events are likely to result from genetic modifications of biofuel algae, they do feel it would be worth our while to confirm this before beginning mass production and cultivation of these organisms.

Probably the most important question is whether the algae can become invasive at all, or whether they will just live out their entire lives in isolated production tanks. If they can escape, it would be important to know how often this would happen, and why--for instance, would the algae be spread by wildlife vectors, blown in by inclement weather, released as a result of human error? Further, how far might species disperse, and how long would they survive in their new habitats? Given the nature of gene transfer among microorganisms, it would also be vital to understand whether modified genetic material could spread to other organisms--including native bacteria with which humans would be likely to encounter on a regular basis.

(Algae from the genus Chlamydomonas. Image courtesy of NYU.)

The authors are frustrated by the fact that very little funding is offered for research on these important topics; further, much of what funding there is is provided by organizations that have a vested interest in the success of modified algae, and therefore may not look favorably on negative results. Thus, Snow and Smith recommend extensive work by a diverse group of researchers who have "minimal conflicts of interest." They suggest that studies should focus on the survival and persistence of modified microalgae, as well as their potential to contribute to the gene pool and spur rapid evolution. The authors also urge better exchange of information on genetically engineered algae. Currently, a good deal of algae research is proprietary, and outsiders can only glean information from funding bodies, descriptions in patent applications, and the published comments of employees from biofuel research companies. This makes it difficult for outsiders to "evaluate possible risks, rule out unlikely scenarios, and carry out baseline research on relevant ecological questions."

While this research would be predominantly aimed at protecting the environment (and its inhabitants) from the potential negative impacts of modified algae, it could also have other benefits. For instance, health and safety researchers may uncover algae life history data that can be used by biofuel developers to improve their product. Even better, the existence of definitive evidence that algae are safe is likely to increase public opinion of these organisms--something that would have economic benefits as well as ecological ones.

Snow, A.A. and Smith, V.H. 2012. Genetically engineered algae for biofuels: a key role for ecologists. BioScience 62(8):765-768.

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