Stimulation of dehydrogenase synthesis by cadmium in a cadmium-resistant strain of Saccharomyces cerevisiae.

The activity of dehydrogenase in Saccharomyces cerevisiae was estimated by reduction of 2,3,5-triphenyltetrazolium chloride. By the adaptation of yeast to cadmium, the high activity of dehydrogenase was observed. Furthermore, the activity of dehydrogenase in Cd-resistant cells was increased by growing in medium containing CdSO4. However, the activity of dehydrogenase was inhibited by the addition of CdSO4 to the reaction mixture. The activity of dehydrogenase in Cd-sensitive cells was increased slightly by incubation with low concentrations of CdSO4. High activity of dehydrogenase in Cd-resistant cells was completely negated by the addition of cycloheximide to the incubation medium. The increase of dehydrogenase activity is due partly to de novo synthesis of protein.