Indigenous Saccharomyces cerevisiae strains, occurring in spontaneous wine fermentations, usually display a high genetic polymorphism which can significantly affect sensorial wine qualities. 
 
With the aim to assess the genotypic diversity within natural Saccharomyces cerevisiae populations, some surveys were carried out, by using molecular techniques, in numerous Italian wineries in the course of alcoholic fermentations of musts from different grape varieties during various vintages. 
 
Results pointed out that, independently of the grape variety, a few dominant and recurrent S. cerevisiae strains became the resident microbiota of a given winery. Indeed, when all the obtained different molecular profiles, corresponding to the different S. cerevisiae strains, were subjected to cluster analysis with the Dice coefficient and the UPGMA method, they grouped in clusters according to the winery where they come from. 
 
Moreover, some yeast commercial strains generally used as starter cultures, which were included in the study, grouped into a distinct cluster indicating that they were significantly different from the indigenous strains. 
 
The occurrence of specific S. cerevisiae strains in each winery supports the potential role of these microorganisms in determining terroir-associated wine characteristics and their selection could represent a resource to contribute in preserving the typicality of wines. 
 
Poster presented at Enoforum 2015, 5-7 May, Vicenza (Italy)