Genetic variability and physiological traits of Saccharomyces cerevisiae strains isolated from “Vale dos Vinhedos” vineyards reflect agricultural practices and history of this Brazilian wet subtropical area

Abstract

Vale dos Vinhedos appellation of origin has a very recent history as industrial wine making region. In this study we investigated the genetic and phenotypic variability of Saccharomyces cerevisiae strains isolated from South-Brazilian vineyards in order to evaluate strain fermentation aptitude and copper and sulphites tolerance. Merlot grape bunches were collected from three vineyards and yeast isolation was performed after single bunch fermentation. High genotypic variability was found and most of the genotypes revealed to be vine-specific. No industrial strain dissemination was present in the sampled vineyards, although it has been wildly reported in traditional winemaking countries. From the phenotypic traits analysis these Brazilian native strains showed good fermentation performances, good tolerance to sulphites and, in particular, a high copper tolerance level. Copper is the most important metal in the formulation of fungicides against downy mildew (Plasmopara viticola), one of the most harmful disease of the vines, and other fungal pests. The high tolerance to copper suggests an environmental adaptation to the strong use of copper-based fungicides, requested by the wet subtropical climate.

Capturing yeast associated with grapes and spontaneous fermentations of the Negro Saurí minority variety from an experimental vineyard near León

“…The biodiversity of Saccharomyces strains is proposed to be as important as that of non-Saccharomyces in the sensorial qualities of the final wine 25 . Numerous reports exist that examine the biodiversity and distribution of individual strains isolated from vineyards and spontaneous fermentations from different wine regions in Europe 9,[26][27][28][29][30][31][32][33][34][35] as well as developing wine regions including China 36 , Brazil 37,38 , India 39 and Russia 40 . Correlations have been made between the genetic diversity and agricultural practices 41 , vineyard diffusion of commercial starters 42,43 , grape variety 44,45 and geographical distances 46 .…”

Spontaneous fermentation in wine production as a controllable technology

“…According to Arroyo-López, Querol and Barrio (2009), an even more accurate indicator of total yeast growth is the percentage of inhibition as this parameter is indirectly related to the delayed phase but linearly related to both the maximum specific growth rate (µmax) and the maximum cell density at the end of growth. Consequently, there is an advantage of condition, which according to Salvadó et al (2011), represents the difference in µmax between competitors for specific environmental conditions. This leads to higher concentrations of highfrequency strains, indicating their enhanced adaptability to increasing ethanol concentrations compared to lowfrequency strains.…”

Produção de ésteres por leveduras não-Saccharomyces: uma exploração

“…As leveduras foram isoladas de vinhedos da cultivar de Uva Merlot, plantados no Vale dos Vinhedos, na cidade de Bento Gonçalves, na região da Serra Gaúcha e na cidade de Vacaria, na região dos Campos de Cima da Serra. A identificação do gênero (Saccharomyces ou não-Saccharomyces) foi realizada por PCR Muliplex Página | 79 (Reação em Cadeia da Polimerase) e visualização por microscópio (CROSATO et al, 2018). A levedura Saccharomyces cerevisiae (SC) foi utilizada como controle.…”