Interaction among heavy metals and methanol affecting superoxide dismutase activity in Saccharomyces cerevisiae.

1. Three strains of Saccharomyces cerevisiae have been exposed to methanol both in the presence and absence of heavy metal ions. The growth curves and the superoxide dismutase activity were determined. 2. The presence of alcohol, copper or cadmium alone did not give strong cytotoxic effects, while methanol plus cadmium yielded a growth inhibition in two strains. 3. SOD levels were stimulated by copper, while methanol did not affect SOD in this non-methylotrophic yeast, indicating the need of alcohol assimilation to stimulate SOD. Cadmium had no inducing effects on SOD levels.