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:The budding yeast Saccharomyces cerevisiae is a popular host to be used to produce recombinant proteins. Here we studied three yeast strains with different productivity using the RNA-seq data to elucidate the mechanisms for improving protein production.
Project description:Reprogramming a non-methylotrophic industrial host, such as Saccharomyces cerevisiae, to a synthetic methylotroph reprents a huge challenge due to the complex regulation in yeast. Through TMC strategy together with ALE strategy, we completed a strict synthetic methylotrophic yeast that could use methanol as the sole carbon source. However, how cells respond to methanol and remodel cellular metabolic network on methanol were not clear. Therefore, genome-scale transcriptional analysis was performed to unravel the cellular reprograming mechanisms underlying the improved growth phenotype.
Project description:Saccharomyces cerevisiae has been used as a secretion host for production of various products, including pharmaceuticals. However, few antibody molecules have been functionally expressed in S. cerevisiae due to the incompatible surface glycosylation. Our laboratory previously isolated a group of yeast mutant strains with different α-amylase secretory capacities, and these evolved strains have showed advantages for production of some heterologous proteins. However, it is not known whether these secretory strains are generally suitable for pharmaceutical protein production. Here, three non-glycosylated antibody fragments with different configurations (Ran-Fab fragment Ranibizumab, Pex-the scFv peptide Pexelizumab, and Nan-a single V-type domain) were successfully expressed and secreted in three background strains with different secretory capacities, including HA (wild type), MA (evolved strain), and LA (evolved strain). However, the secretion of Ran and Nan were positively correlated with the strains’ secretory capacity, while Pex was most efficiently secreted in the parental strain. Therefore, transcriptional analysis was performed to explore the fundamental changes triggered by the expression of the different pharmaceutical proteins in these selected yeast strains.
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:Nickel-resistant Saccharomyces cerevisiae mutant was obtained by evolutionary engineering. The reference strain which was used to select this nickel-resistant mutant could not grow even at 0.5 mM NiCl2 whereas this mutant was shown to be resistant upto 5.3 mM NiCl2 concentration. Whole-genome microarray analysis might be promising to identify the nickel resistance mechanisms in the yeast cells.
Project description:Yeast mannoproteins contribute to several aspects of wine quality by protecting wine against protein haze, reducing astringency, retaining aroma compounds and stimulating growth of lactic-acid bacteria. The selection of a yeast strain simultaneously overproducing mannoproteins and showing good fermentative characteristics is a difficult task. In this work, a Saccharomyces cerevisiae x Saccharomyces cerevisiae hybrid bearing the two oenologically relevant features was constructed and a reduction in the amount of bentonite necessary for wine stabilization was observed for wines fermented with the generated strain. Additionally, different copy numbers of some genes probably related with these physiological features were detected in this hybrid. Hybrid share with parental Sc1 similar copy number of genes SPR1, SWP1, MNN10 and YPS7 related to cell wall integrity and with parental Sc2 similar copy number of some glycolytic genes as GPM1 and HXK1 as well as genes involved in hexose transport as HXT9, HXT11 and HXT12. This work demonstrates that artificial hybridization and stabilization in winemaking conditions constitute an effective approach to obtain yeast strains with desirable physiological features as mannoprotein overproducing capacity and improved fermentation performance, characteristics genetically depending on the coordinated expression of a multitude of different genes. In this work, genetically stable mannoprotein overproducing Saccharomyces cerevisiae strains simultaneously showing excellent fermentation capacities were obtained by hybridization methods giving rise to non-GMO strains. The potential relationship between the copy number of specific genes and the improved features was also evaluated by means of aCGH analysis of parental and hybrid strains.
Project description:We investigated the genome-wide distribution of Okazaki fragments in the commonly used laboratory Saccharomyces cerevisiae strain S288C to study the DNA replication model adopted by the budding yeast. The method based upon lambda exonuclease digestion for purification of RNA-primed replication intermediates was first improved to be suitable for the purification of Okazaki fragments. Then, we used this improved method to purify Okazaki fragments from S288C yeast cells, followed by Illumina sequencing. We found that the expected asymmetric distribution of Okazaki fragments around confirmed replication origins, which was derived from the semi-discontinuous DNA replication model, was not observed on S. cerevisiae chromosomes. Even around two highly efficient replication origins, ARS522 and ARS416, the ratios of Okazaki fragments on both strands were inconsistent with the semi-discontinuous DNA replication model. Our study supported the discontinuous DNA replication model. Besides, we also observed that Okazaki fragments were overpresented in the transcribed regions in S. cerevisiae mitochondrial genome, which indicated the interplay between transcription and DNA replication. Examination of the distribution of Okazaki fragments in Saccharomyces cerevisiae strain S288C.
Project description:In wine fermentation, the blending of non-Saccharomyces yeast with Saccharomyces cerevisiae to improve the complexity of wine has become common practice, but data regarding the impact on yeast physiology and on genetic and metabolic regulation remain limited. Here we describe a transcriptomic analysis of single species and mixed species fermentations.