SOUTH BEND, November 29, 2011 – Replacing gasoline, diesel and jet fuels with clean, green and renewable alternatives is not easy. However, researchers with the U.S. Department of Energy’s (DOE) Joint BioEnergy Institute (JBEI) announced today that they have bioengineered the first strains of Escherichia coli (E. coli) bacteria that can digest switchgrass and synthesize its sugars into all three transportation fuels. In addition, the microbes do that without help from enzyme additives, an expensive step in the conversion process.
“This work shows that we can reduce one of the most expensive parts of the biofuel production process, the addition of enzymes to depolymerize cellulose and hemicellulose into fermentable sugars,” says Jay Keasling, JBEI CEO, who also holds appointments with Lawrence Berkeley National Laboratory and the University of California, Berkeley. “This will enable us to reduce fuel production costs by consolidating two steps . . . into a single step or one pot operation.” Advanced biofuel, made from non-food crops and agricultural waste, is widely considered as the best future potential for renewable liquid transportation fuels.
Corn ethanol, like that produced at South Bend’s New Energy Plant, is used to extend gasoline and cannot be used in some vehicles. The advantage of ethanol produced from corn starch is that it is a proven technology, available today.
Advanced biofuels replace gasoline on a gallon-for-gallon basis. They also can be used across a wider range of transportation vehicles. The problem is to bring the cost of these fuels down so that they can be economically competitive.
Much work still needs to be done, but this is believed to be the first time bioengineered strains of E. coli have produced all three transportation fuels using switchgrass, which is considered a major potential feedstock for advanced biofuel. Research was supported in part by DOE’s Office of Science and a University of California Discovery Grant.
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