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Expression Differences in Ethanol Stress Response Between Saccharomyces cerevisiae Parent W303-1A Strain and its Two Ethanol Tolerant Mutants

ABSTRACT: Saccharomyces spp. are widely used for ethanol production however fermentation productivity is negatively affected by the impact of ethanol accumulation on yeast metabolic rate and viability. This study used microarray and statistical two-way ANOVA analysis to compare and evaluate gene expression profiles of two previously generated ethanol-tolerant mutants, CM1 and SM1, with their parent, S. cerevisiae W303-1A, in the presence and absence of ethanol stress. Although sharing the same parentage, the mutants were created differently; SM1 by adaptive evolution involving long-term exposure to ethanol stress, and CM1 using chemical mutagenesis followed by adaptive evolution-based screening. Compared to the parent, differences in the expression levels of genes associated with a number of GO categories in the mutants suggest that their improved ethanol stress response is a consequence of increased mitochondrial and NADH oxidation activities, stimulating glycolysis and energy production. This leads to increased activity of energy-demanding processes associated with the production of proteins and plasma membrane components, which are necessary for acclimation to ethanol stress. It is suggested that a key function of the ethanol stress response is restoration of the NAD+/NADH redox balance, which increases glyceraldehyde-3-phosphate dehydrogenase activity, and higher glycolytic flux in the ethanol-stressed cell. Both mutants achieved this by a constitutive increase in carbon flux in the glycerol pathway as a means of increasing NADH oxidation.

ORGANISM(S): Saccharomyces cerevisiae

PROVIDER: GSE21120 | GEO | 2010/07/01

SECONDARY ACCESSION(S): PRJNA126477

REPOSITORIES: GEO

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Expression Differences in Ethanol Stress Response Between Saccharomyces cerevisiae Parent W303-1A Strain and its Two Ethanol Tolerant Mutants

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