Comparing the implantation and persistence of inoculated active dry yeast in different industrial wine fermentations

Abstract:

[Background] Yeasts play an important role during the wine fermentation. In China, most wineries use active dry yeast (ADY) to make wine during industrial fermentations. However, there are few reports on the influence of ADY on indigenous yeast resources and on the competitive relationship between them. [Objective] The purpose of this study was to compare the implantation and persistence of commercial ADY during industrial wine productions using different grape varieties, and to reveal the genetic diversity of different Saccharomyces cerevisiae genotypes. [Methods] In this study, Cabernet Sauvignon, Marselan, Dunkelfelder and Petit Verdot grew in Eastern Foot of Helan Mountain in Ningxia were inoculated with commercial yeast SP. Samples were collected at 1 d, 3 d and 5 d after the inoculation, and 20 S. cerevisiae isolates were collected in each period. Then the genetic diversity of S. cerevisiae was analyzed by Interdelta fingerprinting and microsatellite molecular markers. [Results] For the 240 S. cerevisiae isolates, Interdelta showed 24 genotypes. SP showed 4 genotypes of SP1-SP4, and indigenous yeast showed 20 genotypes of Type1-Type20. For 9 microsatellite loci selected, the above 24 genotypes were further divided into 15 different genotypes by the microsatellite method. SP showed 3 genotypes (SP-1-SP-3), and the indigenous yeast showed 12 genotypes (L-1-L-12). In Cabernet Sauvignon wine fermentation, SP existed in the whole fermentation process and was the dominant strain on 1 d, 3 d and 5 d, while in Marselan wine fermentation, SP was only detected and dominated on 5 d, while the indigenous strains dominated on 1 d and 3 d. Interdelta analysis and SSR analysis showed that SP was not isolated in the whole process of Dunkelfelder wine fermentation. In the fermentation of Petit Verdot wine, SP was the dominant strain on 1 d and 3 d. [Conclusion] In industrial wine fermentations inoculated with commercial yeast SP, the fermentation was completed by both indigenous strains and commercial ADY. Moreover, they competed with each other in the same fermentation and showed a dynamic succession of different strains. The dominant position of SP in wine fermentation was not guaranteed. The genotypes of indigenous S. cerevisiae strains in the industrial wine fermentations were rich. And the degree of variability was high. Compared with SSR, Interdelta fingerprinting showed a higher distinguishing ability for S. cerevisiae strains.