title: Response of Saccharomyces cerevisiae to lead ion stress.
abstract: The response of Saccharomyces cerevisiae to different concentrations of Pb(2+) was investigated. The results demonstrated that the growth of S. cerevisiae in the presence of Pb(2+) showed a lag phase much longer than that in the absence of Pb(2+). The inhibition was dependent upon Pb(2+) concentrations. The Pb(2+) at a concentration of 5 microM inhibited the microbial growth by approximately 30% with regard to control, whereas Pb(2+) at concentration of 2 microM did not have a significant effect on the microbial growth. The existence of Pb(2+) did not perturb cell-protein synthesis and there was a good correlation between dry cell weights and total protein content (R (2) = 0.98). The RNA/DNA ratio in the microbial cells varied with Pb(2+) concentration and there was a significant positive correlation between Pb(2+) concentration and the RNA/DNA ratio. The microbial assimilation of ammonium ion was inhibited by the presence of Pb(2+) in the medium; when Pb(2+) concentration was 10 microM, the microbial ammonium assimilation was inhibited about 50%, in comparison with the control experiment.
authors.affiliation: Laboratory of Environmental Technology, INET, Tsinghua University, Beijing, 100084, People's Republic of China.
authors.forename: Can
authors.initials: C
authors.lastname: Chen
authors.forename: Jianlong
authors.initials: J
authors.lastname: Wang
mesh_terms: D000935:Antifungal Agents / Q000633:toxicity*; D018533:Biomass; D004271:DNA, Fungal / Q000032:analysis; D005656:Fungal Proteins / Q000096:biosynthesis; D007854:Lead / Q000633:toxicity*; D000644:Quaternary Ammonium Compounds / Q000378:metabolism; D012331:RNA, Fungal / Q000032:analysis; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism
chemical_list: D000935:Antifungal Agents; D004271:DNA, Fungal; D005656:Fungal Proteins; D000644:Quaternary Ammonium Compounds; D012331:RNA, Fungal; D007854:Lead