Molecular relationships between Saccharomyces cerevisiae strains involved in winemaking from Mendoza, Argentina.

Three molecular typing techniques were applied to assess the molecular relationships of Saccharomyces cerevisiae strains isolated from winery equipment, grapes, and spontaneous fermentation in a cellar located in "Zona Alta del Río Mendoza" (Argentina). In addition, commercial Saccharomyces strains widely used in this region were also included. Interdelta PCR typing, mtDNA restriction analysis, and microsatellite (SSR) genotyping were applied. Dendrograms were constructed based on similarity among different patterns of bands. The combination of the three techniques discriminated 34 strains among the 35 isolates. The results of this study show the complex relationships found at molecular level among the isolates that share the same ecological environment, i.e., the winemaking process. With a few exceptions, the yeast isolates were generally clustered in different ways, depending on the typing technique employed. Three clusters were conserved independently of the molecular method applied. These groups of yeasts always clustered together and had high degree of similarity. Furthermore, the dendrograms mostly showed clusters combining strains from winery and fermentation simultaneously. Most of the commercial strains included in this study were clustered separately from the other isolates analyzed, and just a few of them grouped with the strains mainly isolated from spontaneous fermentation. Only one commercial strain was clustered repetitively with a noncommercial strain isolated from spontaneous fermentation in the three dendrograms. On the other hand, this study has demonstrated the importance of selecting an appropriate molecular method according to the main objectives of the research.