一株芽孢杆菌对含砷矿物中砷的还原作用
发布时间：2018-08-16 16:22
【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12~24 h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。
[Abstract]:In the natural environment, arsenic is usually adsorbed on or coprecipitated with iron oxide, aluminum oxide and other metal oxide minerals. Under anaerobic conditions, microbes may influence the migration and transformation of arsenic through direct reduction of arsenic or reduction of arsenic bearing minerals such as iron oxides. In this study, a Bacillus strain DX-04was selected, and the reduction of arsenate in different forms was studied. Under anaerobic condition, the strain DX-04 had the strongest ability to reduce dissolved arsenic within 24 h, and dissolved arsenic could obviously promote the biomass of bacteria. The concentration of As (III) in the ferric arsenic coprecipitation medium of the inoculated strain DX-04 increased first and then decreased, the arsenic was reduced and released, and then the secondary precipitation was fixed again. When the arsenic bearing alumina mineral was used as the model mineral, the adsorbed As (V) was first released from the aluminum hydroxide mineral to the liquid phase under the reduction of DX-04 strain, and further reduced to As (III). This action of microorganism can cause arsenic from arsenic bearing minerals to release into water and sediment environment and become a potential threat to human health.
【作者单位】： 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;中国科学院大学;
【基金】：国家自然科学基金项目(41273133)资助
【分类号】：X172;Q939.9
，
本文编号：2186521
[Abstract]:In the natural environment, arsenic is usually adsorbed on or coprecipitated with iron oxide, aluminum oxide and other metal oxide minerals. Under anaerobic conditions, microbes may influence the migration and transformation of arsenic through direct reduction of arsenic or reduction of arsenic bearing minerals such as iron oxides. In this study, a Bacillus strain DX-04was selected, and the reduction of arsenate in different forms was studied. Under anaerobic condition, the strain DX-04 had the strongest ability to reduce dissolved arsenic within 24 h, and dissolved arsenic could obviously promote the biomass of bacteria. The concentration of As (III) in the ferric arsenic coprecipitation medium of the inoculated strain DX-04 increased first and then decreased, the arsenic was reduced and released, and then the secondary precipitation was fixed again. When the arsenic bearing alumina mineral was used as the model mineral, the adsorbed As (V) was first released from the aluminum hydroxide mineral to the liquid phase under the reduction of DX-04 strain, and further reduced to As (III). This action of microorganism can cause arsenic from arsenic bearing minerals to release into water and sediment environment and become a potential threat to human health.
【作者单位】： 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;中国科学院大学;
【基金】：国家自然科学基金项目(41273133)资助
【分类号】：X172;Q939.9
，
本文编号：2186521
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