Researchers cut out expensive pretreatment step

Source: Amanda Peterka, E&E reporter • Posted: Thursday, June 5, 2014

Scientists have learned to convert biomass to fuel without pretreatment, a development that could lead to cheaper biofuels.

Researchers affiliated with the Department of Energy’s BioEnergy Science Center fed switch grass, miscanthus and other non-food crops to bacteria engineered for fuel production. The bacteria deconstructed the hard parts of the plant without a need for additional steps.”This is really the beginning of a platform for manipulating organisms to make many products that are truly sustainable,” Janet Westpheling, lead author of the study and a professor at the University of Georgia, said in a statement yesterday.

The results were published this week in the Proceedings of the National Academy of Sciences.

Pretreatment processes for biofuels are varied and can involve chemical, hot water, gasification and thermal techniques. Pretreatment is generally expensive but is needed to break down the cell walls and other tough parts of plants before biomass can be converted into fuel.

The scientists led by Westpheling spent 2 ½ years developing a version of Caldicellulosiruptor bescii, a bacterium that is found around the world from Russia to Yellowstone National Park, that could bypass the pretreatment step.

“Now, without any pretreatment, we can simply take switch grass, grind it up, add a low-cost, minimal salts medium and get ethanol out the other end,” Westpheling said. “This is the first step toward an industrial process that is economically feasible.”

DOE’s BioEnergy Science Center is headquartered at Oak Ridge National Laboratory and supported by the DOE Office of Science.