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).
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:Saccharomyces cerevisiae IMS0002 which, after metabolic and evolutionary engineering, ferments the pentose sugar arabinose. Glucose and arabinose-limited anaerobic chemostat cultures of IMS0002 and its non-evolved ancestor IMS0001 were subjected to transcriptome analysis to identify key genetic changes contributing to efficient arabinose utilization by strain IMS0002.
Project description:Thermotolerance development of robust Saccharomyces cerevisiae is necessary to enhance enzyme activity of cellulase, lower cooling costs, and reduce cell harm from the bad-distributed heat transfer in large-scale fermentation. The process-based studies of adaptive evolution have been well documented, but it remains unknown for the underlying molecular mechanism of the improved thermotolerance and the facilitated ethanol fermentability derived from adaptive evolution. Here, a robust thermotolerant S. cerevisiae Z100 was obtained with significantly improved ethanol fermentability under the stress of high temperature (50 oC) after 91 days’ adaptive evolution. RNA sequencing showed that adaptive evolution and its derived thermotolerance contributed to the unique gene transcriptional landscapes of the evolved strain. An interesting phenomenon was that the gene transcriptional signals of carbon metabolism were strengthened not at 50 oC but at 30 oC in S. cerevisiae Z100, and thus suggested that the improved thermotolerance led to the enhanced ethanol fermentability at 30 oC. The deeply repressed gene transcriptional expression indicated ribosome would be another key thermotolerant mechanism for the evolved strain. This study would provide a robust thermotolerant S. cerevisiae for bioethanol production and an important clue for future synthetic biology to thermotolerance engineering of fermentation strains.
Project description:Saccharomyces cerevisiae IMS0002 which, after metabolic and evolutionary engineering, ferments the pentose sugar arabinose. Glucose and arabinose-limited anaerobic chemostat cultures of IMS0002 and its non-evolved ancestor IMS0001 were subjected to transcriptome analysis to identify key genetic changes contributing to efficient arabinose utilization by strain IMS0002. Glucose- and arabinose limited anaerobic chemostat cultivation of strains IMS0002 and glucose limited IMS0001 at D= 0.03 h-1
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:We did transcription profiling on the effect of Zymolyase in Saccharomyces cerevisiae using strains BY4741 (wild type). Yeast cells exposed to Zymolyase in YPD growth medium show a significant induction of cell wall compensatory mechanism. Keywords: cell wall stress response
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:Creating Saccharomyces yeasts capable of efficient fermentation of pentoses such as xylose remains a key challenge in the production of ethanol from lignocellulosic biomass. Metabolic engineering of industrial Saccharomyces cerevisiae strains has yielded xylose-fermenting strains, but these strains have not yet achieved industrial viability due largely to xylose fermentation being prohibitively slower than that of glucose. Recently, it has been shown that naturally occurring xylose-utilizing Saccharomyces species exist. Uncovering the genetic architecture of such strains will shed further light on xylose metabolism, suggesting additional engineering approaches or possibly even the development of xylose-fermenting yeasts that are not genetically modified. We previously identified a hybrid yeast strain, the genome of which is largely Saccharomyces uvarum, which has the ability to grow on xylose as the sole carbon source. Despite the sterility of this hybrid strain, we were able to develop novel methods to genetically characterize its xylose utilization phenotype, using bulk segregant analysis in conjunction with high-throughput sequencing. We found that its growth in xylose is governed by at least two genetic loci: one of the loci maps to a known xylose-pathway gene, a novel allele of the aldo-keto reductase gene GRE3, while a second locus maps to an allele of APJ1, a chaperonin gene not previously connected to xylose metabolism. Our work demonstrates that the power of sequencing combined with bulk segregant analysis can also be applied to a non-genetically-tractable hybrid strain that contains a complex, polygenic trait, and it identifies new avenues for metabolic engineering as well as for construction of non-genetically modified xylose-fermenting strains.