一株芽孢杆菌对含砷矿物中砷的还原作用  

Reduction of arsenic in arsenic bearing minerals by a Bacillus strain

作　　者：邓博環 许丽英[1] 王玉龙[1,2] 王新[1] 贾永峰[1] 

机构地区：[1]中国科学院沈阳应用生态研究所污染生态与环境工程重点实验室,沈阳110016 [2]中国科学院大学,北京100049

出　　处：《生态学杂志》2016年第12期3374-3381,共8页Chinese Journal of Ecology

基　　金：国家自然科学基金项目(41273133)资助

摘　　要：在自然环境中，砷通常吸附于铁氧化物、铝氧化物等金属氧化物矿物上，或与这些氧化物矿物形成共沉淀。厌氧条件下，微生物可能通过直接还原砷或者还原铁氧化物等载砷矿物从而影响砷的迁移转化。本研究筛选得到芽孢杆菌属的一株细菌DX-04，并研究了该菌株对不同形态砷酸盐的还原作用和还原途径。厌氧条件下，在12～24h内菌株DX-04对溶解态砷的还原能力最强，溶解态砷对提高细菌生物量具有明显的促进作用。接种菌株DX-04的铁砷共沉淀培养基中液相As（III）浓度呈先升高后降低的趋势，砷发生还原与释放，进而发生二次沉淀再次被固持。当以载砷氧化铝矿物为载砷的模型矿物时，在DX-04菌株的还原作用下，吸附的As（V）首先从氢氧化铝矿物上释放到液相，进一步被还原为As（III）。微生物的这一作用能够引起含砷矿物中的砷向水体、沉积物环境中释放，成为人类健康的潜在威胁。In natural environment, arsenic is usually adsorbed on iron oxide, aluminum oxide and other oxide minerals, or formed co-precipitation with these oxide minerals. Microorganisms can reduce arsenate directly or reduce As-bearing iron oxides and other arsenic bearing minerals under anaerobic condition, which could influence the transformation of arsenic. In this study, a bacteria strain was screened and identified as Bacillus sp. （ strain DX-04） , and the reduction be- havior and pathway of the strain on different speciations of the arsenic was studied. Under anaero- bic conditions, reduction rate of arsenate with the strain DX-04 was highest in 12-24 h. Arsenate in the medium promoted the growth of the strain DX-04. In the liquid medium inoculated with strain DX-04 and Fe-As co-precipitation, the concentration of dissolved As （III） showed the trend of increase at first and decrease several hours later. Arsenic reduction and release occurred, and then the second precipitation was formed. Under the reduction of the strain DX-04, the As （V） adsorbed on aluminum hydroxide minerals released into the liquid phase, and then the dissolved As （V） was reduced. The role of microorganisms can cause the release of arsenic from arsenic bearing minerals into water and sediment environment, which becomes a potential threat to hu- man health.

关 键 词：砷 芽孢杆菌 微生物砷还原 铁砷共沉淀 氢氧化铝 

分 类 号：X172[环境科学与工程—环境科学] Q939.9[生物学—微生物学]