Project description:During fermentation Saccharomyces yeast produces various aroma-active metabolites determining the different characteristics of aroma and taste in fermented beverages. Amino acid utilization by yeast during brewer´s wort fermentation is seen as linked to flavour profile. To better understand the relationship between the biosynthesis of aroma relevant metabolites and the importance of amino acids, DNA microarrays were performed for Saccharomyces cerevisiae strain S81 and Saccharomyces pastorianus var. carlsbergensis strain S23, respectively. Thereby, changes in transcription of genes were measured, which are associated with amino acid assimilation and its derived aroma-active compounds during fermentation.
Project description:The Mediator complex transmits activation signals from DNA bound transcription factors to the core transcription machinery. Genome wide localization studies have demonstrated that Mediator occupancy not only correlates with high levels of transcription, but that the complex also is present at transcriptionally silenced locations. We provide evidence that Mediator localization is guided by an interaction with histone tails, and that this interaction is regulated by their post-translational modifications. A quantitative, high-density genetic interaction map revealed links between Mediator components and factors affecting chromatin structure, especially histone deacetylases. Peptide binding assays demonstrated that pure wild type Mediator forms stable complexes with the tails of Histone H3 and H4. These binding assays also showed Mediator – histone H4 peptide interactions are specifically inhibited by acetylation of the histone H4 lysine 16, a residue critical in transcriptional silencing. Finally, these findings were validated by tiling array analysis, that revealed a broad correlation between Mediator and nucleosome occupancy in vivo, but a negative correlation between Mediator and nucleosomes acetylated at histone H4 lysine 16. Our studies show that chromatin structure and the acetylation state of histones are intimately connected to Mediator localization. Med8-TAP strain ChIPed with IgG beads vs. Input in Saccharomyces cerevisiae
Project description:Transcriptomic study to characterize the interaction of the Penicillium expansum antifungal protein PeAfpA with the the model yeast Saccharomyces cerevisiae. For this, the transcriptome of S. cerevisiae BY4741 strain was compared among samples treated with increasing concentrations of PeAfpA.
Project description:In this study, we present an investigation of the yeast response to the exposure to octanoic and decanoic acids, two major fermentation inhibitors. Aerobically grown cells of Saccharomyces cerevisiae U13 wine strain have been exposed to 0,05 mM of octanoic and decanoic acid. We have compared the variations of expression induced by the acid challenges in comparison to a reference non trated modality, as well as the two acid responses. The transcriptome analysis is build in a triangular design in which the RNA extracted from three modalities : reference (non treated cells) , cells exposed to octanoic acid, and cells exposed to decanoic acid are compared.
Project description:During fermentation Saccharomyces yeast produces various aroma-active metabolites determining the different characteristics of aroma and taste in fermented beverages. Amino acid utilization by yeast during brewer´s wort fermentation is seen as linked to flavour profile. To better understand the relationship between the biosynthesis of aroma relevant metabolites and the importance of amino acids, DNA microarrays were performed for Saccharomyces cerevisiae strain S81 and Saccharomyces pastorianus var. carlsbergensis strain S23, respectively. Thereby, changes in transcription of genes were measured, which are associated with amino acid assimilation and its derived aroma-active compounds during fermentation. 48 samples were used in this experiment
Project description:The aim of this project was to evaluate the ploidy of a S. cerevisiae *S. kudriavzevii hybrid in comparison to the lab strain S288C. Other wine yeast have been icluded in the project for the global analysis.
Project description:The vanillin tolerance Saccharomyces cerevisiae was screened and compared intracellular ergosterol levels with several laboratory yeast strains, to study potential relationship between ergosterol contents and vanillin tolerance. S. cerevisiae NBRC1950 was selected as a vanillin tolerant strain. Its ergosterol contents were higher than those of laboratory strains. The results of DNA microarray and quantitative RT-PCR analysis showed that 5 genes involved in ergosterol biosynthesis (ERG28, HMG1, MCR1, ERG5 and ERG7) were up-regulated in NBRC 1950 compared with strain X2180, suggested that high expressions of genes involved in ergosterol biosynthesis may cause for the high ergosterol content in strain NBRC 1950. S. cerevisiae HX strain, which was a high ergosterol content strain derived from X2180, became more tolerant to vanillin compared with the parental strain. It is suggested that high ergosterol contents may be in part responsible for vanillin tolerance. These findings provide a biotechnological basis for the molecular engineering of S. cerevisiae with increased tolerance to vanillin.
Project description:Saccharomyces cerevisiae is an excellent microorganism for industrial succinic acid production, but high succinic acid concentration will inhibit the growth of Saccharomyces cerevisiae then reduce the production of succinic acid. Through analysis the transcriptomic data of Saccharomyces cerevisiae with different genetic backgrounds under different succinic acid stress, we hope to find the response mechanism of Saccharomyces cerevisiae to succinic acid.