Yeast diversity investigation of wine-related samples from two different Slovakian wine-producing areas through a multistep procedure

A multistep procedure was applied in order to investigate the yeasts diversity during the must fermentation of two wine varieties Frankovka Modra (Blaufrankisch) and Veltlinske Zelene (Gruner Veltliner) from two different Slovakian wine-producing areas. The procedure combined a cultivation step with a PCR-based selection step (f-ITS PCR; fluorescence internal transcribed spacer 2 polymerase chain reaction), and a final identification step oriented to the sequencing of ITS1-5.8S rDNA-ITS2 region of the selected yeasts. The strategy demonstrated to be suitable for the rapid analysis of a large panel of isolates. The f-ITS PCR was able to discriminate the isolated yeasts by one PCR run and capillary electrophoresis separation. The investigation showed the presence of non-Saccharomyces strains on grapes and during the initial and middle stages of must fermentation. Members of the genus Saccharomyces appeared only during the middle fermentation stage and they were the predominant species until the final phase of the process. The presented simple and reliable multistep procedure can be useful for the investigation of the yeast microflora from any wine-producing area and also for studying other kinds of food environments. (C) 2011 Elsevier Ltd. All rights reserved.