大肠杆菌一种环境菌株对某些重金属的耐受性。

The tolerance of an environmental strain of Escherichia coli to some heavy metals.

作者信息

Morozzi G, Cenci G, Caldini G

出版信息

Zentralbl Bakteriol Mikrobiol Hyg B. 1982 Apr;176(1):55-62.

Abstract

The effect of mercury, cadmium, copper, zinc, chromium and lead on an environmental strain of Escherichia coli was studied. The tolerance growth limits, growth kinetics and viability were determined. It was found that metal-ion concentrations greater than the threshold values (0.005 microM Hg2+, 0.5 microM Cd2+, 5 microM Cu2+, 23 microM Cr3+, 30 microM Zn2+, 45 microM Pb2+) increase the lag-phases but do not modify the growth kinetics (Pb2+ is an exception). During the lag-phase a reduction in cell viability, varying from a maximum of 89% for lead, to a minimum of 13% for cadmium, was observed. The reduction of viability accounts for a cells physiological adaptation to the metals rather than selection of resistant mutants. Loss of the acquired metal resistance following exposure of the bacterial cells to the metals supported this last point.

摘要

研究了汞、镉、铜、锌、铬和铅对大肠杆菌环境菌株的影响。测定了耐受生长极限、生长动力学和活力。结果发现，高于阈值（0.005微摩尔汞离子、0.5微摩尔镉离子、5微摩尔铜离子、23微摩尔铬离子、30微摩尔锌离子、45微摩尔铅离子）的金属离子浓度会延长延迟期，但不会改变生长动力学（铅离子是个例外）。在延迟期内，观察到细胞活力降低，铅导致的降低最大为89%，镉导致的降低最小为13%。活力降低是细胞对金属的生理适应，而非抗性突变体的选择。细菌细胞暴露于金属后获得的金属抗性丧失支持了这一观点。