几株细菌的重金属抗性水平和吸附量

Resistance and Adsorption of Several Bacterial Strains to Heavy Metals

从堆积时间为80~100 a的铅锌矿渣中分离了6株细菌,通过测定部分16S rRNA基因序列确定了它们的系统发育地位。结果表明有3株细菌属于节杆菌属(Arthrobacter),同A.nicotinovorans和A.histidinolovorans两个种关系密切。另外3株属于壤霉菌属(Agromy-ces),同Ag.m ediolanus具有较近的亲缘关系。总体来看,这些菌株都对检测的5种重金属有高的最低抑菌浓度(m in im al inh ib itory concentration,M IC)。节杆菌对Zn、Co的耐受明显高于壤霉菌。此外,这些重金属高抗性菌株也对重金属有较强的吸附能力。在环境中有单一重金属离子的情况下,冻干的节杆菌对Pb的吸附率平均达到了约400mg/g干菌体,对Cd和Zn的吸附也分别达到了近177和80mg/g干菌体,具有进一步开发为重金属吸附剂的潜力。

Six bacterial strains were isolated from lead-zinc mine tailings with the age of about 100 years, and their phylogenetic position was determined by the analysis of partial 16S rRNA gene sequence. Three strains belonged to genus Arthrobacter, and were close to A. nicotinovorans and A. histidinolovorans. Other three strains belonged to genus Agromyces, and were close to Ag. mediolanus. All of them were resistant to Pb(NO_(3))_(2), CdCl_(2), ZnSO_(4), CuSO_(4) and CoCl_2. Relatively, minimal inhibitory concentration(MIC)of Zn^(2+) and Co^(2+) of three Arthrobacter strains was significantly higher than that of three Agromyces strains. Additionally, these strains displayed strong adsorption of Pb(NO_(3))_(2), CdCl_(2), ZnSO_(4). Averagely three Arthrobacter strains could adsorb about 400mg of Pb^(2+), 177mg of Cd^(2+) or 80mg of Zn^(2+) per gram of dried cells. Therefore, these strains were important candidates for application in bioremediation of heavy metal-contaminated environment.