engleski

Biodiversity of indigenous Saccharomyces cerevisiae population in spontaneous fermentations of grape musts from cv. Plavac mali

Spontaneous process of grape juice fermentation is carried out by mixed populations of wild indigenous yeasts. The requirements for these yeasts are the ability to dominate during the fermentation process and additionaly enhance the sensorial characteristics of the wine. Detailed genetic definition of indigenous yeast strains could enable selection and application as a starter cultures in specific wines typical for certain regions. The main goal of these investigations was isolation, identification and determination of genetic variability of indigenous Saccharomyces cerevisiae natural population taken from cv. Plavac mali from secluded wine growing areas of the Pelješac peninsula and as well as from the island Hvar. Must samples were taken during the spontaneous alcoholic fermentation followed by yeast isolation. A total of 40 isolates that were physiologically confirmed to belong to the Saccharomyces sensu stricto group were further differentiated by molecular methods. PCR-RFLP analyses identified 37 of the isolates as S. cerevisiae, 2 of the isolates as S. bayanus/pastorianus and one as S. paradoxus. All isolates were further analysed by RAPD which yielded characteristic DNA patterns for each tested strain. Results of the RAPD analysis confirmed genetic diversity of S. cerevisiae indigenous population. Comparation of strains within each fermentation phase revealed differences among strains depending upon each investigated location.

S. cerevisiae; identification; PCR-RFLP; RAPD

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