If concerns for global climate change and ever-increasing costs weren't enough, the disastrous Gulf oil spill makes an even more compelling case for the development of transportation fuels that are renewable, can be produced in a sustainable fashion, and do not put the environment at risk. Liquid fuels derived from plant biomass have the potential to be used as direct replacements for gasoline, diesel and jet fuels if cost-effective means of commercial production can be found.
Researchers with the U.S. Department of Energy (DOE)'s Joint BioEnergy Institute (JBEI) have identified a trio of bacterial enzymes that can catalyze key steps in the conversion of plant sugars into hydrocarbon compounds for the production of green transportation fuels.
Harry Beller, an environmental microbiologist who directs the Biofuels Pathways department for JBEI's Fuels Synthesis Division, led a study in which a three-gene cluster from the bacterium Micrococcus luteus was introduced into the bacterium Escherichia coli. The enzymes produced by this trio of genes enabled the E. coli to synthesize from glucose long-chain alkene hydrocarbons. These long-chain alkenes can then be reduced in size a process called "cracking" to obtain shorter hydrocarbons that are compatible with today's engines and favored for the production of advanced lignocellulosic biofuels.
"In order to engineer microorganisms to make biofuels efficiently, we need to know the applicable gene sequences and specific metabolic steps involved in the biosynthesis pathway," Beller says. "We have now identified three genes encoding enzymes that are essential for the bacterial synthesis of alkenes. With this information we were able to convert an E. coli strain that normally cannot make long-chain alkenes into an alkene producer."
Working with Beller on this study were Ee-Been Goh and Jay Keasling. The three were the co-authors of a paper that appeared earlier
|Contact: Lynn Yarris|
DOE/Lawrence Berkeley National Laboratory