Heat shock-induced changes in the respiration of the yeast Saccharomyces cerevisiae

The incubation of Saccharomyces cerevisiae at elevated temperature (45 degr eesC) stimulated the respiration of yeast cells and decreased their surviva l rate. The respiration-deficient mutant of this yeast was found to be more tolerant to the elevated temperature than the wild-type strain. At the sam e time, the cultivation of the wild-type strain in an ethanol-containing me dium enhanced the respiration, catalase activity, and thermotolerance of ye ast cells, as compared with their growth in a glucose-containing medium. It is suggested that the enhanced respiration of yeast cells at 45 degreesC l eads to an intense accumulation of reactive oxygen species, which may be on e of the reasons for the heat shock-induced cell death.