Diversity and killer behaviour of indigenous yeasts isolated from the fermentation vats surfaces in four patagonian wineries

SANGORRÍN M.; LOPES C. A.; GIRAUDO M. R.; CABALLERO A. C.

INTERNATIONAL JOURNAL OF FOOD MICROBIOLOGY

Elsevier

Año: 2007 vol. 119 p. 351 - 357

0168-1605

The diversity and killer behaviour of yeast biota associated with four Patagonian wineries surfaces were analyzed in the present study. These wineries were different in their technological and ecological features. Yeast species assessment was carried out by biochemical test and PCR-RFLP of ITS1-5.8 rDNA-ITS2. Yeast strains were also characterized using killer sensitivity patterns. Out of 92 isolated yeasts analysed, 25 % were Saccharomyces cerevisiae; 18 % were Kloeckera apiculata and 11 % were Pichia anomala; other six species representing a low percentage were also found. As regards enological practices, the wineries using spontaneous fermentation showed a major percentage of S. cerevisiae and a minor percentage of K. apiculata. The analysis of the results shows that the S. cerevisiae isolates have a higher sensitivity to collection yeasts toxins than non-Saccharomyces isolates. On the other hand, most of the non-Saccharomyces yeasts isolated from fermentation vats are immune to Saccharomyces toxins. The present study shows a great heterogeneity in killer behaviour (Killer, 35%, neutral, 25% and sensitive, 40%) and yeasts species associated with Patagonian wineries surfaces. A particular biota composed mainly by S. cerevisiae (57%) and P. anomala (37%) was found in a winery located far from the other three wineries. The results obtained in this study suggest the presence of a characteristic biota in the wineries of each viticultural area. Additionally, the continuous use of commercial yeasts could reduce the diversity and extension of indigenous S. cerevisiae strains resident in wineries environment increasing their killer character.