Phenotypic Landscape of Saccharomyces cerevisiae during Wine Fermentation: Evidence for Origin-Dependent Metabolic Traits

The species Saccharomyces cerevisiae includes natural strains, clinical isolates, and a large number of strains used in human activities. The aim of this work was to investigate how the adaptation to a broad range of ecological niches may have selectively shaped the yeast metabolic network to generate specific phenotypes. Using 72 S. cerevisiae strains collected from various sources, we provide, for the first time, a population-scale picture of the fermentative metabolic traits found in the S. cerevisiae species under wine making conditions. Considerable phenotypic variation was found suggesting that this yeast employs diverse metabolic strategies to face environmental constraints. Several groups of strains can be distinguished from the entire population on the basis of specific traits. Strains accustomed to growing in the presence of high sugar concentrations, such as wine yeasts and strains obtained from fruits, were able to achieve fermentation, whereas natural yeasts isolated from “poor-sugar” environments, such as oak trees or plants, were not. Commercial wine yeasts clearly appeared as a subset of vineyard isolates, and were mainly differentiated by their fermentative performances as well as their low acetate production. Overall, the emergence of the origin-dependent properties of the strains provides evidence for a phenotypic evolution driven by environmental constraints and/or human selection within S. cerevisiae

Control of lactate production by Saccharomyces cerevisiae expressing a bacterial LDH gene

25 ref.International audienc

Re-assessment of the influence of yeast strain and environmental factors on glycerol production in wine

39 ref.International audienc

Engineering a Saccharomyces cerevisiae Wine Yeast That Exhibits Reduced Ethanol Production during Fermentation under Controlled Microoxygenation Conditions

We recently showed that expressing an H(2)O-NADH oxidase in Saccharomyces cerevisiae drastically reduces the intracellular NADH concentration and substantially alters the distribution of metabolic fluxes in the cell. Although the engineered strain produces a reduced amount of ethanol, a high level of acetaldehyde accumulates early in the process (1 g/liter), impairing growth and fermentation performance. To overcome these undesirable effects, we carried out a comprehensive analysis of the impact of oxygen on the metabolic network of the same NADH oxidase-expressing strain. While reducing the oxygen transfer rate led to a gradual recovery of the growth and fermentation performance, its impact on the ethanol yield was negligible. In contrast, supplying oxygen only during the stationary phase resulted in a 7% reduction in the ethanol yield, but without affecting growth and fermentation. This approach thus represents an effective strategy for producing wine with reduced levels of alcohol. Importantly, our data also point to a significant role for NAD(+) reoxidation in controlling the glycolytic flux, indicating that engineered yeast strains expressing an NADH oxidase can be used as a powerful tool for gaining insight into redox metabolism in yeast

Stress effect of ethanol on fermentation kinetics by stationary-phase cells of Saccharomyces cerevisiae

International audienc

Impact des ajouts de nutriments sur les arômes fermentaires

Impact des ajouts de nutriments sur les arômes fermentaire

Influence of nutrients and temperature on the production of fermentative aromas in winemaking conditions using a Box-Behnken design

Influence of nutrients and temperature on the production of fermentative aromas in winemaking conditions using a Box-Behnken design. 5. Conference on Physiology of Yeast and Filamentous Fung

Influence of nutrients and temperature on the production of fermentative aromas in winemaking conditions by an evolved wine strain of Saccharomyces cerevisiae

Influence of nutrients and temperature on the production of fermentative aromas in winemaking conditions by an evolved wine strain of Saccharomyces cerevisiae. Macrowine 201

Influence of nutrients and temperature on the production of fermentative aromas in winemaking conditions using a Box-Behnken design

Influence of nutrients and temperature on the production of fermentative aromas in winemaking conditions using a Box-Behnken design. 5. Conference on Physiology of Yeast and Filamentous Fung