Enzyme cocktail could eliminate a step in biofuel process

physorg.com

December 27, 2010

Conversion of biomass to fuel requires several steps: chemical pretreatment to break up the biomass – often dilute (sulfuric) acid, detoxification to remove the toxic chemicals required in pretreatment, and microbial fermentation to convert the soluble sugars to fuels. Virginia Tech researchers have discovered an enzyme mixture that works in the presence of the toxic infused liquid biomass (hydrolysate), meaning that the detoxification step is unnecessary, reducing the cost of producing biofuels as well as increasing biofuel yields by avoiding the production of by-products and synthesis of cell mass.

The research will be published in the January 2011 issue of the journal Chemistry & Biology.

"Enzymes self-assemble a cell-free synthetic pathway; that is, we can put the desired biological reactions to work without the other complex interactions that take place within a cell," said Y.H. Percival Zhang, associate professor of biological systems engineering at Virginia Tech.

"In microbial fermentations, glucose serves as both a growth substrate and a source of energy for generating a reduced power -- NADPH. In fact, only a small fraction of glucose is allocated to NADPH generation," he says. "The cell-free synthetic pathway process increases efficiency and reaction rate."

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