Project description:In this study, we focused on air-drying stress and analyzed the changes in gene expression of commercial baker’s yeast during the air-drying process. Changes in gene expression profiles of commercial baker’s yeast during an air-drying process at 37oC that simulated dried yeast production were analyzed using DNA microarrays. Keywords: Stress response
Project description:Environmental conditions are quite effective during propagation and industrial application of Baker’s yeast (Saccharomyces cerevisiae). The change of temperature is one of the most important conditions which affects the dough-leaving capacity of yeast cells. Accordingly, heat changes play an essential role in the commercial and economic impact of the yeast. Recent technologies in genomics have been used for analysis of global gene expression profiles such as microarray and RNA sequencing to solve the problems related with industrial application of yeast. Hereby, the aim of this study is to explore the effects of heat stresses on global gene expression profiles and to identify the candidate genes for the heat stress response in commercial baker’s yeast by using microarray technology and comparative statistical data analyses. Data from all hybridizations and array normalization were analyzed using the GeneSpringGX 12.1 (Agilent) and the R 2.15.2 program language. In the analysis of this dataset, all required statistical methods are performed comparatively in each step and the best performed ones are used in further computations. Hence, as the first step of the analyses, different background normalization algorithms such as MAS5.0, RMA, MBEI and GC-RMA were applied and the algorithm which gives the most accurate findings was chosen for the normalization procedure. As a result, expression values, computed from CEL files, were processed by Robust Multiarray Analysis (RMA) which is the selected procedure for the normalization of the systematic differences between samples. In order to determine differentially expressed genes under heat stress treatments, two different methods, namely, the fold-change and the hypothesis testing approaches are executed. In the fold-change method, various cut-off values are implemented while different multiple testing procedures are performed for the hypothesis testing. Under the heat shock and temperature-shift stress conditions, up/down regulated differentially expressed probes were functionally categorized into the different groups via the cluster analyses. Transcriptome changes under the heat shock and temperature-shift stress treatments show that the number of differentially up-regulated genes among the heat shock proteins (HSPs) and transcription factors (TFs) changed significantly. Consequently, the identification of thousands of genes related with heat stress treatments via microarray technology and comparative statistical analysis resulted in the creation of big picture which provides the understanding of the importance for the baker’s yeast industrial applications.
Project description:Metabolic engineering of Saccharomyces cerevisiae for efficient monoterpenes production was mostly restricted by the limited tolerance to these chemicals. Understanding of the molecular mechanisms underlying the tolerance of S. cerevisiae to monoterpenes was essential for the de novo biosynthesis these chemicals in S. cerevisiae. In this study, commercial oligonucleotide microarray assays were performed to investigate the global response of S. cerevisiae to typical monoterpene D-limonene under transcriptional level. Yeast cell treated with sublethal dose of D-liomonene, gene change profiles were investigated at transcription level and the microarry data were also verified with quantitative real time PCR.
Project description:In this study, we used Saccharomyces cerevisiae to investigate the effects of GRX deletion on yeast chronological life span (CLS). Deletion of Grx1 or Grx2 shortened yeast CLS. Quantitative proteomics revealed that GRX deletion increased cellular ROS levels to activate Ras/PKA signal pathway. Our results provided new insights into mechanisms underlying aging process.
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: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.
Project description:Metabolic engineering of Saccharomyces cerevisiae for efficient monoterpenes production was mostly restricted by the limited tolerance to these chemicals. Understanding of the molecular mechanisms underlying the tolerance of S. cerevisiae to monoterpenes was essential for the de novo biosynthesis these chemicals in S. cerevisiae. In this study, commercial oligonucleotide microarray assays were performed to investigate the global response of S. cerevisiae to typical monoterpene D-limonene under transcriptional level. Yeast cell treated with sublethal dose of D-liomonene, gene change profiles were investigated at transcription level and the microarry data were also verified with quantitative real time PCR. D-limonene induced gene expression in Saccharomyces cerevisiae at early logarithmic phase was measured at 2 hours after exposure to doses of 0.02% (v/v) D-limonene. Three independent experiments were performed for each experiment (control or 2 hours).