Selection Of High Effective Mercury-degrading Strain And Cloning And Sequence Analysis Of MerA Gene From This Bacterium

【Objective】: Through HgCl2-selected media, some special bacterial stains would be isolated from mercury- polluted soil, and then the best one should be selected on the basis of the phenotypic, physiological, biochemical tests and genic sequence analysis. All these results will help to apply the selected one into bioremediation of mercury-contaminated soil and water actually.【Methods】:①Isolation of high mercury-resistant bacteria: use HgCl2-selected media to incubate the bacteria out of the soil which we collect from fluorescent lamp's manufactory by normal process. Different colonies would be incubated alone, and then we will discriminate them by tests including: the Gram's staining; phenotypic, phy-siological and biochemical test; antibiotic resistance test, and so on.②Hg2+ toleration test: incubate the bacteria by using the media that have different Hg2+ concentrations, and then observe the growing of those bacteria.③Researches on the growing of the selected high mercury- degrading bacterium: including monitor the bacterium's growth under different Hg2+ concentrations or pH conditions; observing its ability of living in the soil and natural water.④Testing the level of transforming Hg2+ into Hg0: inoculate the growing bacteria which are just on logarithmic growth phase into several LB liquid media that contain different definite Hg2+ concentrations. After 48 hours, collect the liquid by centrifugation to determine the rudimental Hg2+ concentration on AFS-230a double-tracts atomic fluorescence absorptiometer.⑤Classification and identification: according to the reserved 16SrRNA sequences by comparing the same bacterial strains in...