铅锌矿尾矿坝分离节杆菌12-1对Pb2+的耐受和吸附性能研究

摘要

The extensive exploitation and usage of lead resources have caused serious environmental pollution problems currently. Bioremediation of Pb2 + contaminated water and soil environments using microbes is regarded as a promising technology due to the advantages of its cost-effective, easy operation and environmental-friendly properties. In order to understand Pb2+ biosorption characterization of microbes, an indigenous lead-resistant bacterium-Arthrobacter sp. 12-1(GenBank No. KM362724) was isolated from lead-zinc mine tailing dam, and the process and mechanism of Pb2+ biosorption by Arthrobacter sp. 12-1 were furtherly investigated in this study. Study on the growth of Arthrobacter sp. 12-1 in LB medium containing different concentration of Pb2+suggested that the highest Pb2+tolerant concentration of Arthrobacter sp. 12-1 was 800 mg/L. In water solution, 105 mg/L of Pb2+could be reduced to 2.17 mg/L by Arthrobacter sp. 12-1 within 24 h with biosorption rate of 97.93%. Microscopic investigation (atomic force microscopy and scanning electronic microscopy) combined with energy dispersive X-ray spectroscopy analysis showed that lead containing mineral was formed on the surface of cell after Pb2+sorption by Arthrobacter sp. 12-1. Further fourier transform infrared (FT- IR) analysis revealed that carboxyl, amide and phosphate groups of Arthrobacter sp. 12-1 might be involved in Pb2 + biosorption process. The results demonstrated that the Arthrobacter sp. 12-1 isolated from lead-zinc mine tailing dam had strong ability of Pb2 + resistance and biosorption, indicating an attractive prospect of practical applications in bioremediation Pb2+ contaminated water and soil environments. The present work provides much fundamental information for help in constructing feasible strategies for Pb2+bioremediation in the environment.%当前铅资源的粗放式开采和使用对环境造成了严重的污染。利用微生物修复铅污染具有费用低、易操作、环境友好等优点，在水体和土壤铅污染治理中具有很好的应用前景。为了了解微生物对铅的吸附特性，本研究从铅锌矿尾矿坝分离到的一株耐铅节杆菌(Arthrobacter sp.)12-1(GenBank登录号：KM362724)，并研究其对铅的吸附过程和作用机制。研究耐铅节杆菌12-1在含不同Pb2+浓度LB培养基中的生长情况表明，其最高可耐受800 mg/L Pb2+。在水溶液中，经24 h吸附，耐铅节杆菌12-1可将Pb2+浓度从105 mg/L降至2.17 mg/L，吸附率为97.93%。显微成像(原子力显微镜,扫描电镜)观察和能谱分析表明，耐铅节杆菌12-1吸附铅后在细胞表面形成含铅的矿物。傅立叶变换红外光谱(FT-IR)分析表明，耐铅节杆菌12-1细胞上的羧基、酰胺和磷酸基团可能参与了铅的吸附和固定过程。以上结果表明，从铅锌矿尾矿坝分离到的耐铅节杆菌12-1对铅具有较好的耐受和吸附能力，显示其在铅污染环境修复中具有潜在的应用前景。本研究为细菌修复铅污染环境的实践提供了理论基础。