Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Global phenotypic and genomic comparison of two Saccharomyces cerevisiae wine strains

ABSTRACT: 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). Two Saccharomyces cerevisiae strains with divergent phenotype in their capacity to grow and ferment at low temperature were analyzed (P5 strain as a candidate with a good performance in fermentations at low temperature (15ºC) and P24 as a candidate with a worse behavior at low temperature). All experiments were performed using triplicates arrays, and Cy5-dCTP and Cy3-dCTP dye-swap assays were performed to reduce dye-specific bias.

ORGANISM(S): Saccharomyces cerevisiae

SUBMITTER: Estéfani García-Ríos

PROVIDER: E-GEOD-60140 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

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Publications

Global phenotypic and genomic comparison of two Saccharomyces cerevisiae wine strains reveals a novel role of the sulfur assimilation pathway in adaptation at low temperature fermentations.

García-Ríos Estéfani E López-Malo María M Guillamón José Manuel JM

BMC genomics 20141203

<h4>Background</h4>The wine industry needs better-adapted yeasts to grow at low temperature because it is interested in fermenting at low temperature to improve wine aroma. Elucidating the response to cold in Saccharomyces cerevisiae is of paramount importance for the selection or genetic improvement of wine strains.<h4>Results</h4>We followed a global approach by comparing transcriptomic, proteomic and genomic changes in two commercial wine strains, which showed clear differences in their growt ...[more]

PMID: 25471357

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Project description:Wine produced at low temperature is often considered to improve sensory qualities. However, there are certain drawbacks to low temperature fermentations: e.g. low growth rate, long lag phase, and sluggish or stuck fermentations. Selection and development of new Saccharomyces cerevisiae strains well adapted at low temperature is interesting for future biotechnological applications. This study aimed to select and develop wine yeast strains that well adapt to ferment at low temperature through evolutionary engineering, and to decipher the process underlying the obtained phenotypes. To this end, we used a pool of 27 commercial yeast strains and set up batch serial dilution experiments to mimic wine fermentation conditions at 12 ºC. Evolutionary engineering was accomplished by using the natural yeast mutation rate and mutagenesis procedures. One strain (P5) outcompeted the others under both experimental conditions and was able to impose after 200 generations. The evolved strains showed improved growth and low-temperature fermentation performance compared to the ancestral strain. This improvement was acquired only under inositol limitation. The transcriptomic comparison between the evolved and parental strains showed the greatest up-regulation in four mannoprotein coding genes, which belong to the DAN/TIR family (DAN1, TIR1, TIR4 and TIR3). Genome sequencing of the evolved strain revealed the presence of a SNP in the GAA1 gene and the construction of a site-directed mutant (GAA1Thr108) in a derivative haploid of the ancestral strain resulted in improved fermentation performance. GAA1 encodes a GPI transamidase complex subunit that adds GPI, which is required for inositol synthesis, to newly synthesized proteins, including mannoproteins. Thus we demonstrate the importance of inositol and mannoproteins in yeast adaptation at low temperature and the central role of the GAA1 gene by linking both metabolisms. The first aim of this study was to assess the most competitive strains that grow under wine fermentation conditions at low temperature. To this end, we performed a growth competition assay with 27 commercial wine strains inoculated at equal population size in synthetic grape must. In spite of the economical and industrial importance of these strains, their phenotypic variation in the main enological traits, particularly those related to optimum growth temperature, and their ability to adapt to low temperature fermentation have been poorly investigated. The second goal was to obtain an improved strain to grow and ferment at low temperature by evolutionary engineering. For this purpose, we maintained growth competition in synthetic grape must during 200 generations to select for the mutations that produce phenotypes with improved growth in this medium. One of these evolved cultures was previously treated with ethyl methanesulfonate (EMS) to increase the mutation rate. Finally, we aimed to decipher the molecular basis underlying this improvement by analyzing the genomic and transcriptional differences between the parental strain and the strain evolved at low temperature.

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Dataset Information

Global phenotypic and genomic comparison of two Saccharomyces cerevisiae wine strains

Publications

Global phenotypic and genomic comparison of two Saccharomyces cerevisiae wine strains reveals a novel role of the sulfur assimilation pathway in adaptation at low temperature fermentations.

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