The most important yeast in biotechnology is Saccharomyces cerevisiae, which shares its primary ecological niche with a closely related species Saccharomyces paradoxus. The purpose of our work was to preserve genetic potential of 386 yeast strains isolated in Vipava valley and to determine their genetic diversity. Six yeast strains were preserved at –80 °C and their survival rate was determined after one and four months. Yeasts survival rate declined over time. The highest survival rates were found in species Dekkera bruxellensis, S. cerevisiae, Metschnikowia pulcherrima and Rhodotorula glutinis. Based on PCR-RFLP results of the ITS region we could differentiate S. cerevisiae and S. paradoxus from other yeast species. Five and nine percent of S. paradoxus and S. cerevisiae out of 204 isolates, respectively, were of non-vineyard origin. Other yeast species of genera Candida, Debaryomyces, Hanseniaspora, Kluyveromyces, Metschnikowia, Meyerozyma, Lachancea, Pichia, Schwanniomyces, Torulaspora and Zygosaccharomyce were identified by sequencing of the ITS region and their genetic diversity was determined by (GTG)5x fingerprinting. By combining genetic diversity in microsatellite hypervariable regions of the Saccharomyces species and their phenotypes, we determined two distinct groups of S. cerevisiae vineyard strains, one resistant to high concentration of ethanol and glucose, and the second to potassium metabisulphite.
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