The oxidative stress response of the yeast Candida intermedia to copper, zinc, and selenium exposure.

The yeast Candida intermedia, as a model organism, was used to examine the links between the metal ions exposure, reactive oxygen species generation and oxidative stress response. To estimate intracellular peroxide and superoxide levels, the fluorescence indicators dihydrorhodamine 123 and dihydroethidium were used, respectively. Antioxidant defence systems were investigated by measuring the activity of catalase, glutathione peroxidase and superoxide dismutase and the content of reduced glutathione. Altered superoxide, peroxide, glutathione levels, and the catalase activity were perceived after the treatment with copper. In the samples treated with selenium and zinc the altered peroxide and superoxide levels, and the glutathione peroxidase activity were perceived. The results indicate that the tolerance of the yeast C. intermedia to different metal ions was correlated with the reactive oxygen species generation in the cells and with the efficiency of antioxidative defence systems.