A novel test for the identification of genes involved in aldehyde metabolism is proposed, based on detection of altered sensitivity of the yeast to corresponding alcohols, metabolic precursors of the aldehydes. This attitude enabled to an unexpected detection increased sensitivity of mutants devoid of CuZn-superoxide dismutase (CuZnSOD) to allyl alcohol (precursor of acrolein) and nonenol. We interpret this finding as due to inactivation of some important element of aldehyde detoxification by increased flux of superoxide in DeltaCuZnSOD mutants.
View Article and Find Full Text PDFMutants of Saccharomyces cerevisiae devoid of Cu,Zn-superoxide dismutase are hypersensitive to a range of oxidants, hyperbaric oxygen and hyperosmotic media, show lysine and methionine auxotrophy when grown under the atmosphere of air and have a shortened replicative life span when compared to the wild-type strain. Ascorbate and other antioxidants can ameliorate these defects, which may be a basis of simple tests sensing the presence of antioxidants. In particular, tests of growth on solid medium (colony formation) in the absence of methionine and/or lysine, or in the presence of 0.
View Article and Find Full Text PDFYeast (Saccharomyces cerevisiae) mutants lacking CuZnSOD have been reported to be hypersensitive to hypertonic media and to show increased oxidative damage. This study demonstrates that hypertonic medium (containing 0.8 M NaCl) increases the generation of superoxide and other reactive species in yeast cells.
View Article and Find Full Text PDFYeast (Saccharomyces cerevisiae) mutants lacking cytoplasmic superoxide dismutase (CuZnSOD) show Lys and Met auxotrophy under aerobic conditions. This metabolic defect can be ameliorated by exogenous ascorbate as well as other antioxidants (glutathione, cysteine and N-acetylcysteine). Restoration of growth of CuZnSOD- yeast mutants on media devoid of Met and/or Lys may therefore be a simple and useful means to detect and quantify antioxidants.
View Article and Find Full Text PDFYeast (Saccharomyces cerevisiae) mutants lacking CuZn-superoxide dismutase (CuZnSOD) are hypersensitive to oxygen and have significantly decreased replicative life span. Both these defects can be ameliorated by exogenous ascorbate. The effect of ascorbate on life span is complicated by auto-oxidation of its compound in the medium.
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