November 29, 2011

Researchers Genetically Engineer Algae to Increase Oil Yields by Up to 50%: Should We Be Concerned?

Franken-algae may be key to reducing carbon emissions. But do they represent a different environmental threat?

Researchers at Iowa State University say they’ve unlocked a genetic pathway in algae that can dramatically increase the amount of CO2 consumed by the organisms, thus helping recycle more of the greenhouse gas and increasing oil yields for non-food based biofuels by as much as 50%.

ISU photo by Bob Elbert

Algae use two genes — LCIA and LCIB — to help them regulate CO2 intake. When growing in low-CO2 environments, these two genes are activated to help the organisms take in more of the gas to their cells. But when CO2 concentrations are high, the genes are shut off.

Researchers led by Iowa State Professor of Genetics Martin Spalding figured out how to keep those genes turned on all the time, turning this strain of algae (Chlamydomonas reinhardtii) into a CO2-sucking, biomass-producing machine:

When the two genes were expressed together, Spalding was surprised to see the 50 to 80 percent biomass increase.

“Somehow these two genes are working together to increase the amount of carbon dioxide that’s converted through photosynthesis into biomass by the algae under conditions where you would expect there would already be enough carbon dioxide,” said Spalding.

The excess biomass naturally becomes starch through the photosynthesis process, and increases the biomass starch by around 80 percent.

By using some existing mutated genes, Spalding can instruct the algae to make oil instead of starch. This process requires more energy and the process results in around a 50 percent increase in oil biomass.

While this research is promising for limiting carbon emissions and expanding biofuels, it’s not really new. Genetically modified algae are a key part of the “secret sauce” of companies like Sapphire Energy, Solazyme, Synthetic Genomics and TransAlgae, which are all toying with different genetic changes in order to increase oil production.

But what if these organisms — which can very easily leave the lab on clothing, skin or through the air — escape into the natural environment and contaminate the gene pool of wild algae and dramatically increase growth rates?

Researchers say they’ve modified the organisms in different ways to prevent them from thriving the wild. Some are bred with “suicide” genes; others are modified to be domesticated and are unable to live outside the lab.

So far, there have been no cases of genetically modified algae causing problems. However, the Departments of Energy and Agriculture have avoided comprehensive environmental reviews of modified strains.

Industry representatives say it’s important not to add costly reviews at a time when the industry is starting to achieve scale, and say the risks can easily be minimized. Others, like bioenergy expert David Haberman, criticize the government for not putting more thought into potential impacts, saying “the lack of study of the potential hazards is of great concern.”

Haberman has been warning of the threat of genetically modified algae for years — saying rogue organisms could disrupt fisheries, hurt recreation and make people sick. “There’s little oversight and no regulatory regime,” he says.

Genetic modification will continue to be a major part of algae-to-biofuels research. This latest finding from Iowa State is proof of the major positive impact it could have on expanding biofuels production.

But it’s also a reminder that the potential unintended consequences can be equally strong.

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