A STRATEGY FOR CONSTRUCTION OF INDUSTRIAL STRAINS OF DISTILLERS YEAST

A procedure was developed for construction of industrial strains of di stiller's yeast (Saccharomyces cerevisiae). It includes several steps: construction of congenic genetically marked haploid strains of opposi te mating types starting from an industrial strain of hybrid nature, i ntegrative transformation of the above haploid strains with a DNA frag ment containing an expression cassette responsible for new technologic al facilities, and hybridization of transformants and isolation of fin al industrial homozygous strains under experimental conditions simulat ing commercial fermentation processes. This strategy permits the gener ation of strains that have desirable characteristics of traditional ra ces of distiller's yeast along with new technological facilities deter mined by the particular expression cassette. Using this procedure, we have constructed an industrial strain with improved amylolytic activit y. (C) 1995 John Wiley & Sons, Inc.