矿化细菌Bacillus paramycoides对重金属Pb(Ⅱ)和Cd(Ⅱ)的去除及矿化特性

随着金属矿山开采和冶炼活动的增加，重金属污染问题日益严峻，微生物诱导生物矿化可有效固定重金属离子，被认为是一种重要的重金属污染环境修复工艺，对重金属污染生态修复有重要的现实意义。本研究从贵州黔西北某铅锌矿区周边土壤中分离出一株耐Pb(II)和Cd(II)菌株GS-2，经形态学特征和16S rRNA鉴定为Bacillus paramycoides，菌株GS-2对Pb(II)和Cd(II)的耐受分别高达1500和50 mg/L，对250 mg/L Pb(II)和5 mg/L Cd(II)去除率分别为99.54%和69.04%，对重金属Pb(II) 和Cd(II)（均为25 mg/L）混合去除率分别为99.73%和71.6%。SEM-EDS、FTIR和XRD结果显示，菌株通过表面的羟基、羧基、酰胺基和磷酸基团等官能团将Pb(II)和Cd(II)诱导矿化成Ca2.5Pb7.5(OH)2(PO4)6、Ca2.1Pb7.9Cl2(PO4)6、Pb3(PO4)2、Pb5(PO4)3OH、Pb9(PO4)6、Pb10(PO4)6(OH)2和Ca0.67Cd0.33CO3等晶体矿物。菌株GS-2具有较好的去除和矿化能力，对环境中Pb(II)和Cd(II)污染的生物修复具有一定应用潜力。

Removal and mineralization of heavy metals Pb(Ⅱ) and Cd(Ⅱ) by mineralizing bacterium Bacillus paramycoides

With the increase of metal mining and smelting activities, the problem of heavy metal pollution is becoming more and more serious. 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(II) and Cd(II) 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(II) and 5 mg/L Cd(II) were 99.54% and 69.04%, respectively, and the removal rates of heavy metal Pb(II) and Cd(II) (both 25 mg/L) were 99.73% and 71.6%, respectively. The results of SEM-EDS, FTIR, and XRD showed that the strain-induced mineralization of Pb(II) and Cd(II) to Ca2.5Pb7.5(OH)2(PO4)6, Ca2.1Pb7.9Cl2(PO4)6, Pb3(PO4)2, Pb5(PO4)3OH, Pb9(PO4)6, Pb10(PO4)6(OH)2 and Ca0.67Cd0.33CO3 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 bioreactor Pb(II) and Cd(II) pollution in the environment.