Exploring the biodiversity of a wine region: Saccharomyces yeasts associated to winery and vineyard

COMBINA M.

Viña de Mar, Chile

Congreso; XIV Congreso Latinoamericano de Genética (ALAG).; 2010

The objective was to determine the Saccharomyces cerevisiae native strains present in grapes, wineries and wines of the ZARM region from Argentina. Two different, but related, aspects were evaluated using a molecular approach for Saccharomyces strain differentiation. First, we tried to elucidate the origin of S. cerevisiae yeasts involved in the spontaneous fermentation of grape musts by evaluating the distribution of these yeasts on winery equipment and determining their contribution to the fermentation process. Their genetic relationships with commercial yeasts were also evaluated. Secondly, we explored S. cerevisiae strain diversity in the ZARM vineyards. The contribution of vineyard Saccharomyces strains to the population responsible for industrial spontaneous fermentations and the level of genetic relationships between these populations were also evaluated. The results showed S. cerevisiae biota resident in both wineries and vineyards. A wide diversity and dynamic behaviour were also found within and between seasons, as was a variable contribution to the fermentation process as well as complex interactions with the commercial yeasts used in the wineries. There was no evidence of a representative strain distributed throughout the viticultural region evaluated. Complex genetic relationships at the molecular level between isolated yeasts which shared the same ecological environment were found. Although a wide diversity was observed, these yeasts shared many characteristics, suggesting a strong selection pressure exerted by the fermentation process could have generated variability at different levels.