[Yeasts associated with spontaneous fermentation processes in wines from Ribeiro. Analysis of homo/heterothallism and the killer system of S. cerevisiae strains].

A taxonomic analysis has been carried out concerning the different yeast species involved in spontaneous fermentations of Ribeiro wine. The results revealed the presence of 15 species belonging to 7 genera: Saccharomyces, Torulaspora, Dekkera, Saccharomycodes, Debaryomyces, Kloeckera and Candida. Within the genus Candida a high number of species was detected. The 28 isolated strains of S. cerevisiae showed with some exceptions, a remarkable sporulation ability and viability of the meiotic products. All the strains were homothallic. Among all S. cerevisiae strains, 6 exhibited killer K2 activity with higher isolation percentages in intermediate fermentations than in late fermentations.