Isolation of indigenous Saccharomyces cerevisiae strains isolated of fermented must from wine grapes in a tropical semiarid region of Brazil.

The present study aimed to isolate, identify and characterize the yeasts of fermented must from grapes in the São Francisco Valley region, Brazil. The grapes were collected from four vineyards in the region and taken to the laboratory for must production and strain isolation. The yeasts were identified by sequencing the D1/D2 variable domains of the largest subunit of the rRNA gene. The Saccharomyces cerevisiae strains were differentiated using the mitochondrial DNA restriction technique (RFLP-mtDNA), and compared with the commercial strains used in the region for wine production. A total of 368 yeasts were isolated, 109 of which were non-Saccharomyces and 259 S. cerevisiae. Of these, 184 were indigenous and 75 commercial varieties. Among the indigenous strains, 22 RFLP-mtDNA and two commercial profiles were characterized. The must of the samples collected was appropriate substrate for identifying and isolating the non-Saccharomyces and S. cerevisiae strains and commercial yeasts. Given that the indigenous strains were more numerous than their commercial counterparts, which were selected in countries with a temperate climate, new studies should be conducted, testing the capacity of indigenous yeasts in producing quality wines, with typicality and regional identity, some of which may become commercially viable.