Project description:The goal of this study is to analyse how the gene expression in Saccharomyces cerevisiae changes in dependency on the glucose concentration. Therefore, fed batch cultivations were carried out, during which the glucose concentration was maintained stable for several hours. Samples were taken at different times during the cultivations, the RNA was isolated and hybridised on whole genome yeast microarrays. Results from cultivations with the glucose concentrations 50, 70, 100 and 500 mg/L are presented. In addition, one sample from a starvation period (0 mg/L glucose) was analysed. Keywords: Dependency on glucose concentration
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:A propolis-resistant Saccharomyces cerevisiae mutant strain was obtained using an evolutionary engineering strategy based on successive batch cultivation under gradually increasing propolis levels. The mutant strain FD 11 was selected at a propolis concentration that the reference strain could not grow at all. Whole-genome transcriptomic analysis of FD11 was performed with respect to its reference strain to determine differences in gene expression levels between the two strains. Saccharomyces cerevisiae
Project description:The pattern of gene transcription in Saccharomyces cerevisiae is strongly affected by the presence of glucose. An increased activity of protein kinase A (PKA), triggered by a rise in the intracellular concentration of cAMP, can account for many of the effects of glucose on transcription. To investigate the requirement of PKA for glucose control of gene expression, we have analyzed global transcription in strains devoid of PKA activity. In S. cerevisiae three genes, TPK1, TPK2, TPK3, encode catalytic subunits of PKA and the triple mutant tpk1 tpk2 tpk3 is unviable. We have worked, therefore, with two strains, tpk1 tpk2 tpk3 yak1 and tpk1 tpk2 tpk3 msn2 msn4, that bear suppressor mutations,. We have identified different classes of genes that can be induced, or repressed, by glucose in the absence of PKA. Among these genes, some are also controlled by a redundant signalling pathway involving PKA activation, while others do not respond to an increase in cAMP concentration. On the other hand, among genes which do not respond to glucose in the absence of PKA, some show a full response to increased cAMP levels, even in the absence of glucose, while others appear to require the cooperation of different signalling pathways.
Project description:Metabolite concentrations can regulate gene expression, which can in turn regulate metabolic activity. The extent to which functionally related transcripts and metabolites show similar patterns of concentration changes, however, remains unestablished. We have therefore measured and analyzed the metabolomic (previously published in Brauer et al., PMID 17159141) and transcriptional responses (presented here) of Saccharomyces cerevisiae to carbon and nitrogen starvation.
Project description:Saccharomyces cerevisiae cannot metabolize cellobiose in nature. Here, S. cerevisiae was engineered to achieve cellobiose utilization by introducing both a cellodextrin transporter gene (cdt-1) and an intracellular β-glucosidase gene (gh1-1) from Neurospora crassa. We sequenced mRNA from anaerobic exponential cultures of engineered S. cerevisiae grown on cellobiose or glucose as a single carbon source in biological triplicate. Differences in gene expression between cellobiose and glucose metabolism revealed by RNA deep sequencing indicated that cellobiose metabolism induced mitochondrial activation and reduced amino acid biosynthesis under fermentation conditions.
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:A Saccharomyces cerevisiae mutant with improved coniferyl aldehyde resistance was obtained by using an evolutionary engineering strategy, based on successive batch cultivation under gradually increased coniferyl aldehyde concentration. The mutant strain BH13 was selected which could grow at a coniferyl aldehyde concentration that the reference strain could not grow at all. Whole-genome transcriptomic analysis of BH13 with respect to the reference strain was performed to identify differences in gene expression levels between the two strains.