PREDOMINANT SACCHAROMYCES-CEREVISIAE STRAINS IN THE FERMENTATION OF AIREN GRAPE MUSTS WITH SO2

In this study the hypothesis that within the spontaneous flora of grap es only a few races of Saccharomyces cerevisiae are tolerant towards S O2 and ethanol was considered. An Airen white variety must which had b een previously sulphited was allowed to ferment and IO yeast colonies were then randomly isolated. The identity of the colonies was establis hed according to both the morphological and biochemical properties, th e result being S. cerevisiae var. bayanus The mitochondrial DNA restri ction analysis corroborated that the isolates belonged to the same str ain. Different enological properties such as the kinetic profile, floc culation strength and killer toxin, were detected between S. cerevisia e var. cerevisiae, used as a standard in this work, and var. bayanus c orresponding to the isolates. (C) 1995 Academic Press Limited