For the three fuels E. coli engineered at JBEI, cellulose and hemicellulose are hydrolyzed by cellulase and hemicellulose enzymes (blue) into oligosaccharides, which are further hydrolyzed by β-glucosidase enzymes (red) into monosaccharides that can be metabolized into biofuels. (Image courtesy of DOE/Lawrence Berkeley National Laboratory)
A milestone has been reached on the road to developing advanced biofuels that can replace gasoline, diesel, and jet fuels with a domestically produced clean, green, renewable alternative. Researchers with the U.S. Department of Energy’s Joint BioEnergy Institute (JBEI) have engineered the first strains of Escherichia coli bacteria that can digest switchgrass biomass and synthesize its sugars into all three of those transportation fuels. What’s more, the microbes are able to do this without any help from enzyme additives.
“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, CEO of JBEI and leader of this research. “This will enable us to reduce fuel production costs by consolidating two steps—depolymerizing cellulose and hemicellulose into sugars and fermenting the sugars into fuels—into a single step or one-pot operation.”
(Sandians working on this project identified the cellulases to be incorporated into the organism and pretreated the biomass using the ionic liquid pretreatment technology developed at JBEI.)
Read the rest of the article at ScienceDaily.