Yeast communities and genetic polymorphism of Saccharomyces cerevisiae strains associated with artisanal fermentation in Brazil

Yeast communities and genetic polymorphism of prevalent Saccharomyces cerev isiae strains isolated from the spontaneous fermentation of the sugarcane j uice during the production of aguardente in three distilleries in the state of Minas Gerais, Brazil, were studied. S. cerevisiae was the prevalent spe cies during the process of aguardente production, but Schizosaccharomyces p ombe was predominant in old fermentations in one distillery. Transient yeas t species were found in a variable number, probably due to the daily additi on of sugarcane juice, and they were different for each of the three distil leries studied. PFGE and PCR analysis of the predominant strains of S. cere visiae isolated from the fermented must showed a high degree of genetic pol ymorphism among the three distilleries. A high molecular variability of S . cerevisae strains was also observed among strains isolated from the same v at at different fermentation ages. Our results showed that there was a succ ession of geneticly different strains of S. cerevisae during the process of aguardente production.