Blue-Green Algae Biofuel Research Continues

Researchers at UC-Davis and one at Sandia National Labs are exploring the use of cyanobacteria for making biofuels. At UC-Davis their cyanobacteria produced 2.4 grams of 2.3 butanediol for each liter of material used. This rate was the highest reported so far for such chemicals intended for commercial development. 2,3 butanediol is an alcohol which is suitable for use as a biofuel, like ethanol. The advantage of producing it instead of ethanol is that it can be converted into jet fuel, as well as used in an internal combustion engine. (Burning this form of buatendiol generates less CO2 and therefore contributes less to climate change.)

Cyanobacteria are also powered by sunlight, so the energy source already exists in ample supply (during daylight hours of course). This research is taking place in the lab headed by Shota Atsumi.

At Sandia, Anne Ruffing has genetically engineered cyanobacteria to make free fatty acids. These chemicals can be made into liquid biofuels. Her work is focused on cyanobacteria because they are easier to genetically manipulate than eukaryotic algae. They also can be altered to create a number of different fuels.

Additionally, they produce the material used to make fuel outside the cell, so it can be collected without damaging the cell. Whereas with eukaryotic algae the pre-fuel material must be extracted from cells, which destroys them so they can’t continue making it. As a result, a new generation of algae must be grown. Cyanobacteria can be used over and over again. However, current yields are not large enough to be commercially viable, which is why Ruffing is experimenting with ways of increasing them.

“So I’m engineering the cell, then I’m trying to learn from the cell how to work with the cell to produce the fuel instead of trying to force it to produce  something it doesn’t want to produce,” she explained.