ISOLATION AND CHARACTERIZATION OF CRYOTOLERANT SACCHAROMYCES STRAINS

Cryotolerant Saccharomyces strains were isolated from grape must (Pino t noir) using the enrichment method (CASTELLARI et al. 1992). Eleven c ryotolerant strains were collected which all belonged to the S. uvarum species (Melibiose test and karyotype). Fermentations were carried ou t at 10 and 25 degrees C, the level of fermentation products was compa red with those produced by mesophilic yeasts. Regardless of temperatur e, cryotolerant yeasts (SY055 and 12233) produced twice as many isobut yl and isoamyl alcohols as mesophilic yeast (FB) and 2-phenethyl alcoh ol was produced by cryotolerant yeasts at levels 4 times as high as by mesophilic yeasts. The potential of these yeasts for oenological appl ication is discussed.