title: Alcohol fermentation of starch by a genetic recombinant yeast having glucoamylase activity.
abstract: Alcohol fermentation of starch was investigated using a direct starch fermenting yeast, Saccharomyces cerevisiae SR93, constructed by integrating a glucoamylase-producing gene (STA1) into the chromosome of Saccharomyces cerevisiae SH1089. The glucoamylase was constitutively produced by the recombinant yeast. The ethanol concentration produced by the recombinant yeast was 14.3 g/L which was about 1.5-fold higher than by the conventional mixed culture using an amylolytic microorganism and a fermenting microorganism. About 60% of the starch was converted into ethanol by the recombinant yeast, and the ethanol yield reached its maximum value of 0.48 at the initial starch concentration of 50 g/L. The fed-batch culture, which maintains the starch concentration in the range of 30 to 50 g/L, was used to produce a large amount of ethanol from starch. The amount of ethanol produced in the fed-batch culture increased about 20% compared to the batch culture. (c) 1997 John Wiley & Sons, Inc.
authors.affiliation: Department of Chemistry and Chemical Engineering, Faculty of Engineering, Kanazawa University, Kanazawa 920, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Nakamura
authors.forename: F
authors.initials: F
authors.lastname: Kobayashi
authors.forename: M
authors.initials: M
authors.lastname: Ohnaga
authors.forename: T
authors.initials: T
authors.lastname: Sawada