Wine strains of S. cerevisiae fermenting with/without lipid supplementation
Ontology highlight
ABSTRACT: Goal was to identify yeast genes whose expression changed as a function of the presence/absence of lipid nutrients during fermentation of two S. cerevisiae wine strains characterized by a different fermentative behaviour.
Project description:We performed here the transcriptomic profile of 44 segregants from a cross between S288c and 59A (a spore of EC1118 strain). The analysis was performed in wine fermentation condition in stationary phase during nitrogen starvation and in alcoholic stress. These data, associated with an individual genotyping by Affymetrix array allow us to highlight genetic variations involved in perturbation of regulatory network and fermentative behavior.
Project description:In wine fermentation, the blending of non-Saccharomyces yeast with Saccharomyces cerevisiae to improve the complexity of wine has become common practice, but data regarding the impact on yeast physiology and on genetic and metabolic regulation remain limited. Here we describe a transcriptomic analysis of single species and mixed species fermentations.
Project description:We used genome-wide expression analyses to study the response of Saccharomyces cerevisiae to stress throughout a 15-day wine fermentation. Forty percent of the yeast genome significantly changed expression levels to mediate long-term adaptation to an environment in which ethanol is both a stressor and a carbon source. Within this set, we identify a group of 223 genes, designated as the Fermentation Stress Response (FSR), that are dramatically and permanently induced; FSR genes exhibited changes ranging from four-to eighty-fold. The FSR is novel; 62% of the genes involved have not been implicated in global stress responses and 28% of the genes have no functional annotation. Genes involved in respiratory metabolism and gluconeogenesis were expressed during fermentation despite the presence of high concentrations of glucose. Ethanol, rather than nutrient depletion, was responsible for entry of yeast cells into stationary phase. Ethanol seems to regulate yeast metabolism through hitherto undiscovered regulatory networks during wine fermentation. Keywords: time course, stress response, fermentation
Project description:The yeast Dekkera bruxellensis is as ethanol tolerant as Saccharomyces cerevisiae and may be found in bottled wine. It causes the spoilage of wine, beer, cider and soft drinks. In wines, the metabolic products responsible for spoilage by Dekkera bruxellensis are mainly volatile phenols. These chemical compounds are responsible for the taints described as ‘‘medicinal’’ in white wines (due to vinyl phenols) and as ‘‘leather’’, ‘‘horse sweat’’ and ‘‘stable’’ in red wines (due to ethyl phenols mainly 4-ethylphenol). Apart from the negative aroma nuances imparted by these yeasts, positive aromas such as ‘smoky’, ‘spicy’ and ‘toffee’ are also cited. Our goal was to identify the impact that the wine spoilage yeast Dekkera bruxellensis has on fermenting S. cerevisiae cells, especially on its gene expression level. To this end we co-inoculated both yeast species at the start of fermentation in a synthetic wine must, using S. cerevisiae-only fermentations without Dekkera bruxellensis as a control. All fermentations were employed in special membrane reactors (1.2 um pore size cut-off) physically separating Dekkera bruxellensis from wine yeast S. cerevisiae. Biomass separation with this membrane was done to abolish the possibility of hybridizing also D. bruxellensis probes on Agilent V2 (8x15K format) G4813 DNA microarrays designed just for S. cerevisiae ORF targets. The 1.2 um pore membrane separating both yeasts allowed the exchange of ethanol, metabolites and sugars during the fermentation.
Project description:Natural grape-juice fermentations involve the sequential development of different yeast species which strongly influence the chemical and sensorial traits of the final product. In the present study,we aimed to examine the transcriptomic response of Saccharomyces cerevisiae to the presence of Hanseniaspora guilliermondii wine fermentation.
Project description:The aim of this study is to phenotype a collection of 27 S. cerevisiae commercial wine strains growing within temperatures (4-45ºC) in both minimal media (SD) and synthetic must (SM) and, taking into account µmax value, to select two strains with divergent phenotype in their capacity to grow at low temperature. To confirm this differential phenotype, we design a competition between both strains during wine fermentations. As expected, at low temperature fermentation, the strain showing a good performance out-competes to the strain growing badly in cold. Finally we aimed to decipher the molecular basis underlying this divergent phenotype by analyzing the genomic, proteomic and transcriptomic differences between both strains at low temperature (15ºC) and optimum temperature (28ºC).
Project description:Comparative gene expression analysis of two wine yeast strains at three time points (days 2, 5 and 14) during fermentation of colombar must. In our study we conducted parallel fermentations with the VIN13 and BM45 wine yeast strains in two different media, namely MS300 (syntheticmust) and Colombar must. The intersection of transcriptome datasets from both MS300 (simulated wine must;GSE11651) and Colombar fermentations should help to delineate relevant and ‘noisy’ changes in gene expression in response to experimental factors such as fermentation stage and strain identity.
Project description:We performed here the transcriptomic profile of 44 segregants from a cross between S288c and 59A (a spore of EC1118 strain). The analysis was performed in wine fermentation condition in stationary phase during nitrogen starvation and in alcoholic stress. These data, associated with an individual genotyping by Affymetrix array allow us to highlight genetic variations involved in perturbation of regulatory network and fermentative behavior. 56 transcriptomic profiles were performed with Agilent mono-color array. 6 hybridizations were performed for each parental strains: 3 technical replicates for 2 biological replicated samples (59As1 and 59As5; S288Cs1 and S288Cs5). One hybridization was performed for each of the 44 segregants. Using mono-color array, the logarithm base 2 of intensity was directly used after normalization.
Project description:Comparison between two commercial wine yeast strains (UCD522 and P29) differing in their production of H2S during wine fermentation.