[Effects of cadmium, zinc, lead and mercury on the growth and accumulating ability of Saccharomyces cerevisiae, Saccharomycopsis lipolytica, Candida tropicalis, and Candida utilis].

The effects of cadmium, zinc, lead, and mercury on the growth and the accumulating ability of Saccharomyces cerevisiae, Saccharomycopsis lipolytica, Candida tropicalis, and Candida utilis had been studied. Generally the experiments resulted in the following findings: Very small concentrations of cadmium and mercury already decrease the growth intensity of the yeasts by lengthening the lag period and the doubling time. The cell yield is not reduced. Zinc increases the productivity of Saccharomyces cerevisiae and Saccharomycopsis lipolytica by shortening the lag period. The lead concentrations investigated show no significant influence on the growth. Low pH values intensify the effectiveness of the four heavy metals. The yeasts tested accumulate heavy metals, especially cadmium, to high concentrations and therefore substrates containing heavy metals are only limited suitable for the scp-production with yeasts.