Project description:Natural S. cerevisiae isolates were evaluated for tolerance to a complex mixture of lignocellulosic inhibitors. Two isolates, with intermediate and superior tolerance characteristics, were investigated to determine the proteomic changes required for tolerance to lignocellulosic inhibitors.
Project description:Lignocellulosic biomass is an abundant renewable resource with tremendous potential to alleviate climate crisis. Yarrowia lipolytica is an attractive biochemical production host, while the presence of inhibitors furfural and acetic acid in lignocellulosic hydrolysate restricts the efficient utilization of this resource. Given a deficient understanding of the inherent interactions between these inhibitors and cellular metabolism, sufficiently mining relevant genes is necessary. Herein, 14 novel gene targets were discovered using CRISPR interference library in Y. lipolytica, achieving tolerance to 0.35% (v/v) acetic acid (the highest concentration reported in Y. lipolytica), 4.8 mM furfural, or a combination of 2.4 mM furfural and 0.15% (v/v) acetic acid. The tolerance mechanism might involve improvements of signal transduction, PP pathway, and TCA cycle. Transcriptional repression of effective gene targets still enabled tolerance when xylose was a carbon source. This work forms a robust foundation for significantly improving microbial tolerance to inhibitors in lignocellulosic hydrolysate and profoundly revealing underlying mechanism.
Project description:Lignocellulosic biomass is an abundant renewable resource with tremendous potential to alleviate climate crisis. Yarrowia lipolytica is an attractive biochemical production host, while the presence of inhibitors furfural and acetic acid in lignocellulosic hydrolysate restricts the efficient utilization of this resource. Given a deficient understanding of the inherent interactions between these inhibitors and cellular metabolism, sufficiently mining relevant genes is necessary. Herein, 14 novel gene targets were discovered using CRISPR interference library in Y. lipolytica, achieving tolerance to 0.35% (v/v) acetic acid (the highest concentration reported in Y. lipolytica), 4.8 mM furfural, or a combination of 2.4 mM furfural and 0.15% (v/v) acetic acid. The tolerance mechanism might involve improvements of signal transduction, PP pathway, and TCA cycle. Transcriptional repression of effective gene targets still enabled tolerance when xylose was a carbon source. This work forms a robust foundation for significantly improving microbial tolerance to inhibitors in lignocellulosic hydrolysate and profoundly revealing underlying mechanism.
Project description:Adaptive evolution experiment for enhaced tolerance to hydrolysates of lignocellulosic biomass in S. cerevisiae. The samples involves a batch culture in YNB and Hydrolysates. Cells were harvested at mid-exponential phase.
Project description:Adaptive evolution experiment for enhaced tolerance to hydrolysates of lignocellulosic biomass in S. cerevisiae. The samples involves a batch culture in YNB and Hydrolysates. Cells were harvested at mid-exponential phase. Three biological replicas of 8 samples vs reference Samples 1-8 are the first replicate, Samples 9-16 are the second replicate, Samples 17-24 are the third replicate.
Project description:The thermophilic anaerobe Clostridium thermocellum is a candidate consolidated bioprocessing biocatalyst for the conversion of lignocellulosic biomass into ethanol. The microorganism expresses enzymes for both cellulose solubilization and fermentation to produce lignocellulosic ethanol making it a good candidate for industrial biofuel production. Intolerance to stresses routinely encountered during industrial fermentations may hinder the commercial development of this organism. A recently published study by Yang et al., (2012) characterized the physiological and regulatory response of C. thermocellum to ethanol supplementation. Significant changes in nitrogen metabolism and an accumulation of carbon sources were identified, revealing potential targets for metabolic engineering. In the current study, the response of C. thermocellum to heat and furfural shock were compared with the known effects of ethanol shock. Improved tolerance to these stresses are desirable traits for C. thermocellum and further understanding of the effects that these particular stresses have on the organism are the focus of this work. A forty one array study using total RNA recovered from wild-type cultures of Clostridium thermocellum at different time points of 10, 30, 60, and 120 min post-treatment with 3.95 g.L-1 ethanol, 4 g.L-1 furfural or 68°C treatment compred to that of control without treatment. At least two biological replicates were performed for each treatment and control condition.
Project description:Evolutionary engineering of Saccharomyces cerevisiae for enhanced tolerance to hydrolysates of lignocellulosic biomass Samples vs Reference
