Poster Presentation 1B-52

Screen of Novel Yeast Strains for Fermentation of Xylose and Glucose

Jose M. Laplaza,¹ Chenfeng Lu,² and Thomas W. Jeffries^1,2

¹USDA, FS, Forest Products Laboratory

One Gifford Pinchot Drive

Madison, WI 53726-2398

Phone: (608)231-9453

Fax: (608)231-9262

E-mail: twjeffri@facstaff.wisc.edu

²Department of Food Science

University of Wisconsin – Madison

Yeasts that ferment both xylose and glucose could be useful for ethanol production industrial settings. Twenty-one novel isolates from the gut of the wood-ingesting beetles, Odontotaenius disjunctus and Verres sternbergianus were obtained from the laboratory of Dr. Meredith Blackwell and screened for both of these properties. One of the yeasts grew very slowly in xylose and was not tested for xylose fermentation. Seven of the novel yeast strains produced at least 2.5% ethanol from 8% xylose under oxygen-limited conditions. Six produced less than 1% after 5 days, and 7 did not produce any detectable ethanol. None of the novel strains produced ethanol at a higher rate than Pichia stipitis CBS 6054. Production of ethanol from 8% glucose under anaerobic conditions starting with a very low cell density was also tested, and only two strains produced significant amounts of ethanol. Interestingly, none of the strains that produced ethanol at a high rate from xylose also produced significant ethanol from glucose under anaerobic conditions.