Ethanol production from D-xylose and other sugars by the yeastPachysolen tannophilus

Summary D-Xylose was fermented to ethanol by a strain ofPachysolen tannophilus in yields greater than 0.3g ethanol per g xylose consumed. Ethanol production was influenced by xylose concentration and was at a maximum at 10%, w/v. Ethanol formation occurred at pH 2.75-2.50 but the yeast would not grow at this pH when the initial pH of the medium was less than 3.0. Ethanol was consumed by the yeast when the xylose concentration became limiting. L-Arabinose, D-glucose, D-fructose, cellobiose, D-glucuronic acid, but not sucrose,were also fermented to ethanol byPachysolen tannophilus. Kinetic studies on xylose fermentation established various parameters involved in growth, substrate utilization and ethanol formation when the yeast was fermenter grown.