Modified yeast can make more ethanol

CHAMPAIGN, Ill., Aug. 19 (UPI) -- A genetically modified strain of yeast with a higher tolerance for alcohol could lead to more efficient and economical biofuel production, researchers say.

A University of Illinois professor of microbial genomics says the modified yeast could improve microbial fermentation of biomass crops, a process that yields the alcohol-based fuels ethanol and iso-butanol as it converts sugars from biomass into biofuels, a university release said Thursday.

"At a certain concentration, the biofuels that are being created become toxic to the yeast used in making them. Our goal was to find a gene or genes that reduce this toxic effect," said Yong-Su Jin, an assistant professor in the university's Department of Food Science said.

Jin worked with Saccharomyces cerevisiae, the microbe most often used in making ethanol, to identify four genes that improve tolerance to ethanol and iso-butanol.

"We expect these genes will serve as key components of a genetic toolbox for breeding yeast with high ethanol tolerance for efficient ethanol fermentation," he said. "Identification of these genes should enable us to produce transportation fuels from biomass more economically and efficiently. It's a first step in understanding the cellular reaction that currently limits the production process."