Researchers at the Great Lakes Bioenergy Research Center have taken a cue from Mother Nature and are evaluating natural strains of yeast to guide the development of industrial strains that will be better able to handle the stressful environments associated with cellulosic and traditional ethanol production. The research group has so far identified certain genes in wild yeast cells that improve their tolerance of ethanol. This information can be used to bioengineer yeast cells that produce higher yields and concentrations of ethanol. The next step is to identify which genes allow some yeast cells to tolerate higher levels of other toxins that are typically found in cellulose. Researchers say that identifying those genes could lead to a significant breakthrough for cellulosic ethanol production.

“We were very pleased with how successful we were in identifying genes that are new engineering targets, but it’s almost like the tip of the iceberg,” said Audrey Gasch, assistant professor of genetics at the University of Wisconsin-Madison. Gasch is also a researcher at the GLBRC and co-author of a study on the group’s research that was published in the December issue of Genetics - the Genetics Society of America’s scientific journal. She said the inability of yeast cells to cope with toxins found in cellulosic material has been a “major bottleneck” in the task of producing cellulosic ethanol efficiently and is now the focus of the team’s research. “The combination of ethanol and these other toxins is kind of a double whammy for the yeast cells,” she said. By further examining various strains of natural yeasts and their ability to resist similar toxins, the group could discover what genes can be “switched on” in industrial strains to allow them to better handle cellulosic materials.

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