Identification of yeasts isolated of the traditional Tepache of Guerrero, Mexico

Abstract

Mexico has a great diversity of fermented beverages and Tepache, is a popular drink with Mixtec origins. Actually is prepared withpineapple, panela-sugarcane and water. The microbiology of the tepache is not known with exactitude, but it is important to knowthe species of yeast involved in the fermentation of the pineapple to know it and optimize its process. The aim of this study was todefine with the molecular technique PCR-RFLP the species that participate in the fermentation of the Tepache from Guerrero. Theresults obtained included a total of eight different restriction patterns of ITS 5.8S region of rDNA from 195 strains isolated fromyeast, corresponding to different species of yeasts. According to these restriction patterns, the yeast species involved in thefermentation of this beverage belong to Candida apicola, C. ethanolica, C. oregonensis, C. tropicalis, Pichia galeiformis,Rhodotorula graminis, Saccharomyces kluyveri and Zygosaccharomyces florentinus. Considering the frequency of the isolates fromspecies, the most abundant species wasC. apicola with 51.3% and Z. florentinus 24.1% of the isolates. According to these resultsTepache from Guerrero is partly fermented with non-Saccharomyces yeast of mature pineapples corresponding to the firstfermentative stage. In conclusion, in the Tepache from Guerrero a fermentation of the mature pineapples by yeasts of the non-Saccharomyces group corresponding to the first fermentative stage occurs, and a partially fermented beverage is obtained.