NOVEL FLOCCULATING YEAST, PRODUCTION THEREOF AND ALCOHOLIC FERMENTATION METHOD USING SAID YEAST

摘要

PURPOSE:To obtain a yeast of the genus Saccharomyces and carry out alcoholic fermentation with improved ethanol productivity using said yeast, by subjecting different auxotrophic strains of yeast of the genus Saccharomyces to protoplast fusion. CONSTITUTION:An auxotrophic stain of a yeast Saccharomyces cerevisiae IFO-1953 and auxotrophic strain of a yeast Saccharomyces S1 (FERM-P No.7794) are subjected to protoplast fusion. the resultant yeast Saccharomyces S1X1953-AA (FERM P-No.8895) has improved flocculation degree of 5 expressed in terms of DF value. The alcoholic fermentation is carried out by putting a preculture fluid of the above-mentioned yeast in a fermenter 1 containing a raw material by using an apparatus shown in the figure according to batch cultivation. When the culture medium is then continuously fed to perform alcoholic fermentation, flocks, are formed in the fermenter 1 by improved flocculation property of this yeast to afford the aimed high-concentration alcohol.