d-Xylose Directly to Ethanol Isolation and Screening of Yeasts That Ferment

anaerobically, and ethanol yieldswere highest under mild agitation. In all cases, a significantproportionofthecarbohydrateconsumedwasnotaccountedfor by biomass and ethanol. The microorganisms thereforemustproduceother metabolites, suchas xylitol (4). Eachofthe yeasts above assimilated xylitol slowly but extensivelyunder standard conditions (12). Strains 83-3 and 83-877-1