engleski

Identification and characterisation of indigenous Saccharomyces cerevisiae strains isolated from cv. Plavac mali

Spontaneous alcoholic fermentation excluding application of selected dry yeasts dominates in traditional red wine production in Croatia. In the most cases, it is led by Saccharomyces cerevisiae strains with different metabolic profiles which have exchangable pattern through the fermentation. Property of certain strain is production of secondary compounds which in return, have influence upon wine aroma giving specific uniqueness. 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, identifiacation and determination of genetic variability of the indigenous Saccharomyces cerevisiae natural population taken from cv. Plavac mali from secluded wine growing areas of the Pelješac peninsula as well as from the island Hvar. Must samples were taken during alcoholic fermentation followed by yeast isolation. Isolates that were physiologically confirmed to belong to the Saccharomyces sensu stricto group were furthermore differentiated by molecular methods. Identification by using PCR-RFLP analyses confirmed that S. cerevisiae is dominant speciaes during spontaneous fermentation despite the incidence of S. paradoxus and S. bayanus/S. pastorianus. However, due to their ecologic and enologic importance their existence should not be discharged. Isolates identified by PCR-RFLP belonging to the S. cerevisiae species, were further analysed by RAPD which yielded characteristic DNA patterns for each tested strain. Results from RAPD analyses confirmed heterogenity of S. cerevisiae population. Comparation of strains from each location revealed differentiation among them regarding each fermentation phase. Within each fermentation phase significant differences between indigenous strains were not detected.

wine yeasts; Saccharomyces cerevisiae; PCR-RFLP; RAPD

nije evidentirano