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: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:A six array study using total gDNA recovered from two separate cultures of each of three different strains of Saccharomyces cerevisiae (YB-210 or CRB, Y389 or MUSH, and Y2209 or LEP) and two separate cultures of Saccharomyces cerevisiae DBY8268. Each array measures the hybridization of probes tiled across the Saccharomyces cerevisiae genome.
Project description:We expressed human RECQL5 in the model organism Sacharomyces cerevisiae. We found that RECQL5 overexpression in yeast leads to cell growth inhibition and increased genotoxic sensitivity. We carried-out transcriptome analysis of yeast strains overexpressing human RECQL5 helicase to explore its impact on gene expression.
Project description:We study the genetics, including microarray karyotyping using comparative genomic hybridization, to explore global changes in the genomic DNA of seven S. cerevisiae strains related to traditional fermentations of very different sources comparing to the sequenced S. cerevisiae laboratory strain (S288C). Our final goal is to determine the adaptive evolution of properties of biotechnological interest in Saccharomyces yeasts. Many copy number variations (CNVs) were observed, especially in genes associated to subtelomeric regions and transposon elements. Among the fermentation strains, differential CNV was observed in genes related to sugar transport and metabolism. An outstanding example of diverse CNV is the gen PUT1, involved in proline assimilation, which correlated with the adaptation of the strains to the presence of this nitrogen source in the media.
Project description:To characterize the ecological interactions among S. cerevisiae strains coming from the same geographical area, we examined the fitness of two natural isolates from San Giovese grapes, alone or in competition, in synthetic wine must (SWM). We performed genome-wide analyses in order to identify the genes involved in yeast competition and cooperation.