The U.S. Department of Energy’s Joint BioEnergy Institute (JBEI) has announced that researchers have engineered a strain of E. coli bacteria that can extract an advanced biodiesel directly from biomass:
“The fact that our microbes can produce a diesel fuel directly from biomass with no additional chemical modifications is exciting and important,” says Jay Keasling, the Chief Executive Officer for JBEI, and a leading scientific authority on synthetic biology. “Given that the costs of recovering biodiesel are nowhere near the costs required to distill ethanol, we believe our results can significantly contribute to the ultimate goal of producing scalable and cost effective advanced biofuels and renewable chemicals.”
E. coli is a well-studied microorganism whose natural ability to synthesize fatty acids and exceptional amenability to genetic manipulation make it an ideal target for biofuels research. The combination of E. coli with new biochemical reactions realized through synthetic biology, enabled Keasling, [Eric Steen, a member of the team from JBEI’s Fuels Synthesis Division] and their colleagues to produce structurally tailored fatty esters (biodiesel), alcohols and waxes directly from simple sugars.
“Biosynthesis of microbial fatty acids produces fatty acids bound to a carrier protein, the accumulation of which inhibits the making of additional fatty acids,” Steen says. “Normally E. coli doesn’t waste energy making excess fat, but by cleaving fatty acids from their carrier proteins, we’re able to unlock the natural regulation and make an abundance of fatty acids that can be converted into a number of valuable products. Further, we engineered our E. coli to no longer eat fatty acids or use them for energy.”
The researchers point out that using E. coli to convert biomass into biodiesel will eliminate a food source from the fuel chain.