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Microbial induced biomineralization can effectively immobilize heavy metal ions, which is considered to be an important process for the environmental remediation of heavy metal pollution, and has important practical significance for the ecological remediation of heavy metal pollution. In this study, a strain GS 2 resistant to Pb() and Cd(J)was isolated from the soil of a lead zinc mining area in northwest Guizhou Province. It was identified as Bacillus paramycoides. Based on morphological characteristics and 16S rRNA. The removal rates of 250 mg/L Pb(If) and 5 mg/L Cd(JJ) were 99. 54% and 69. 04%, respectively, and the removal rates of heavy metal Pb (J) and Cd()(both 25 mg/L) were 99. 73% and 71. 46%, respectively. The results of SEM EDS, FTIR, and XRD showed that the strain induced mineralization of Pb(n)and Cd(n)to Cm. 5 Pb, (OH)2 (PO4)$, C&2. iPb/.gCb (PO4)&, Pb$ (PO4) 2, Pb5 (PO4)g OH, Pb9 (PO4) e, Pbio (PO4) e (OH)2 and Ca0. e, Cd0. $$ COs through the functional groups of hydroxyl, carboxyl, amide and phosphate groups on the surface. Strain GS 2 has great removal and mineralization ability and has certain application potential for bio remediation of Pb(H)and Cd(]J)pollution in the environments. [ABSTRACT FROM AUTHOR]

Under the background of carbonate rocks in karst areas, the life activities of microorganisms in the environment are closely related to metal ions. Microbial-Induced Carbonate Precipitation (MICP) can effectively immobilize heavy metal ions, which is helpful in remediating heavy metal pollution in the environment. In this study, a urease-producing and Pb (Ⅱ)-resistant mineralization strain WH15,which was identified as Klebsiella grimontii by 16S rDNA, was isolated from the surrounding soil of a lead-zinc mining area in northwestern Guizhou province. The mineralization characteristics of Pb (Ⅱ) when calcium source was added, and the mineralization products were characterized by Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS), Fourier Transform Infrared Spectroscopy (FT-IR) and X-Ray Diffraction (XRD). The results showed that the tolerance of strain WH15 to Pb (Ⅱ) was as high as 2 000 mg/L. When the concentration of CaCl2 was 100 mg/L, the mineralization rate of WH15 to 2 000 mg/L Pb (Ⅱ) increased from 82% to 99.7%.SEM-EDS,FTIR and XRD analysis indicated that the strain adsorbed and immobilized Pb (Ⅱ) around the bacteria through the hydroxyl, alkyl, amide, carboxyl and carbonic acid groups on the surface, and the mineral precipitation before and after calcium addition changed from lead phosphate to CaCO3 and PbCO3,the main components were calcite, vaterite and galena. The above results indicate that Klebsiella grimontii WH15 has certain application potential for bioremediation of Pb (Ⅱ) pollution in the environment [ABSTRACT FROM AUTHOR]

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