Project description:Industrial bioethanol production may involve a low pH environment,improving the tolerance of S. cerevisiae to a low pH environment caused by inorganic acids may be of industrial importance to control bacterial contamination, increase ethanol yield and reduce production cost. Through analysis the transcriptomic data of Saccharomyces cerevisiae with different ploidy under low pH stress, we hope to find the tolerance mechanism of Saccharomyces cerevisiae to low pH.
Project description:Evolutionary engineering strategy was used for selection of ethanol-tolerant Saccharomyces cerevisiae clones under gradually increasing ethanol stress levels. Clones B2 and B8 were selected based on their higher ethanol-tolerance and higher ethanol production levels. Whole genome microarray analysis was used for identifying the gene expression levels of these two evolved clones compared to the reference strain.
Project description:ppGpp accumulation caused by ectopic expression of RelA in Saccharomyces cerevisiae gave rise to marked changes in gene expression with both upregulation and downregulation, including changes in mitochondrial gene expression. The most prominent upregulation (38-fold) was detected in the function-unknown hypothetical gene YBR072C-A, followed by many other known stress-responsive genes. ppGpp acuumulation resulted in enhancement of tolerance against various stress stimuli, such as osmotic stress, ethanol, hydrogen peroxide, and high temperature.
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:High concenHigh concentration acetic acid in the fermentation medium represses cell growth, metabolism and fermentation efficiency of Saccharomyces cerevisiae, which is widely used for cellulosic ethanol production. Our previous study proved that supplementation of zinc sulfate in the fermentation medium improved cell growth and ethanol fermentation performance of S. cerevisiae under acetic acid stress condition. However, the molecular mechanisms is still unclear. To explore the underlying mechanism of zinc sulfate protection against acetic acid stress, transcriptomic and proteomic analysis were performed. The changed genes and proteins are related to carbon metabolism, amino acid biosynthesis, energy metabolism, vitamin biosynthesis and stress responses. In a total, 28 genes showed same expression in transcriptomic and proteomic data, indicating that zinc sulfate affects gene expression at posttranscriptional and posttranslational levels.tration acetic acid in the fermentation medium represses cell growth, metabolism and fermentation efficiency of Saccharomyces cerevisiae, which is widely used for cellulosic ethanol production. Our previous study proved that supplementation of zinc sulfate in the fermentation medium improved cell growth and ethanol fermentation performance of S. cerevisiae under acetic acid stress condition. However, the molecular mechanisms is still unclear. To explore the underlying mechanism of zinc sulfate protection against acetic acid stress, transcriptomic and proteomic analysis were performed. The changed genes and proteins are related to carbon metabolism, amino acid biosynthesis, energy metabolism, vitamin biosynthesis and stress responses. In a total, 28 genes showed same expression in transcriptomic and proteomic data, indicating that zinc sulfate affects gene expression at posttranscriptional and posttranslational levels.
Project description:ppGpp accumulation caused by ectopic expression of RelA in Saccharomyces cerevisiae gave rise to marked changes in gene expression with both upregulation and downregulation, including changes in mitochondrial gene expression. The most prominent upregulation (38-fold) was detected in the function-unknown hypothetical gene YBR072C-A, followed by many other known stress-responsive genes. ppGpp acuumulation resulted in enhancement of tolerance against various stress stimuli, such as osmotic stress, ethanol, hydrogen peroxide, and high temperature. A two chip study using total RNA recoverd from the Saccharomyces cerevisiae TN2080 (accumulating ppGpp) and TN2077 (vector control) grown to mid-growth phase (8h) in SC-uracil medium. The plasmid pYC2/CT (V5-epitope tag vector) was used as a vector to express Sj-RSH.
Project description:Transcriptional profiling of ethanol tolerant strains Ets2 and Ets3 comparing control Saccharomyces cerevisiae L3262 with ethanol tolerant strains Ets2 and Ets3, through screening a mutant library of SPT15 of Saccharomyces cerevisiae L3262.
Project description:Evolutionary engineering strategy was used for selection of ethanol-tolerant Saccharomyces cerevisiae clones under gradually increasing ethanol stress levels. Clones B2 and B8 were selected based on their higher ethanol-tolerance and higher ethanol production levels. Whole genome microarray analysis was used for identifying the gene expression levels of these two evolved clones compared to the reference strain. Two evolved ethanol-tolerant strains B2 and B8, which were selected by evolutionary engineering under gradually increasing ethanol stress, were used for whole genome transcriptomic analysis in comparison with the reference strain. Cells were grown in yeast minimal media until they reach a final OD600 of 1. Following total RNA isolation, gene expression levels were analyzed using One-color microarray-based gene expression analysis (Agilent Technologies). Experiments were done in triplicates.
Project description:The environmental stresses and inhibitors encounted by Saccharomyces cerevisiae strains are main limiting factors in bioethanol fermentation. Investigation of the molecular mechanisms underlying the stresses-related phenotypes diversities within and between S. cerevisiae populations could guide the construction of yeast strains with improved stresses tolerance and fermentation performances. Here, we explored the genetic characteristics of the bioethanol S. cerevisiae strains, and elucidated the genetic variations correlated with its advantaged traits (higher ethanol yield under sever conditions and better tolerance to multiple stresses compared to an S288c derived laboratory strain BYZ1). Firstly, pulse-field gel electrophoresis combined with array-comparative genomic hybridization was used to compare the genome structure of industrial strains and the laboratory strain BYZ1.