The isolation and characterization of Ni2+ resistant mutants of Saccharomyces cerevisiae.

Four Ni2+ resistant mutants of Saccharomyces cerevisiae have been isolated and characterized. In the accumulation of Ni2+, there was no significant difference between the wild type strain and the Ni2+ resistant mutants. The synthesis of RNA in the yeast was severely inhibited by Ni2+ while inhibition of protein synthesis was less pronounced. The inhibitory effect of Ni2+ on both RNA and protein synthesis in Ni2+ resistant mutants of yeast was less pronounced than in the wild type strain, while four Ni2+ resistant mutants were more sensitive to Cd2+ and Cu2+ than was the wild type strain. Ni2+ resistant mechanism(s) appeared to exist within the cells and differed from those of Cd2+ or Cu2+.