Effects of Heavy Metal Stress on the Growth Curves of Two Kinds of Bacteria

[Objective] The aim was to study on the effects of heavy metal stress on the growth curves of Escherichia coli and Bacillus subtili.[Method] Using traditional culture method,Escherichia coli and Bacillus subtili were cultured under heavy metal stress including Cu2+,Hg2+,Pb2+,Cd2+ and Cr6+ in different concentrations.Then the growth curves of the bacteria were determined to investigate the effects of exogenous heavy metals on the growth of the two kinds of bacteria.[Result] The proliferation of the two bacteria was inhibited at high concentrations of Hg2+ and Cd2+ respectively,and G+ is more sensitive to them than G-;when the heavy metal concentration was 50 mg/L,the toxicity of the five kinds of heavy metals on the two bacteria was Hg2+Cd2+Cu2+Cr6+≈Pb2+.[Conclusion] The research will provide a basis to explore the effects of heavy metal on environment and ecological system.