Pandey Neha, Bhatt Renu
Department of Biotechnology, Guru Ghasidas Vishwavidyalaya (A Central University), Bilaspur, Chhattisgarh 495009, India.
Toxicol Rep. 2015 Oct 22;2:1367-1375. doi: 10.1016/j.toxrep.2015.10.002. eCollection 2015.
Arsenic is a toxic metalloid existing widely in the environment, and its removal from contaminated water has become a global challenge. The use of bacteria in this regard finds a promising solution. In the present study, sp. As-9, which is an arsenic resistant bacterium, was selected with respect to its arsenic removal efficiency. Quantification of arsenic in the water treated with bacterium showed that efficiently removed up to 99% of arsenic in less than 20 h. In order to reveal the possible effect of this bacterium in removal of arsenic from water and protecting fishes from the detrimental effects of arsenic, we initiated a range of studies on fresh water fish, . It was observed that the fishes introduced into bacteria treated water displayed no symptoms of arsenic toxicity which was marked by a decreased oxidative damage, whereas the fishes exposed to arsenic revealed a significant ( < 0.05) increase in the oxidative stress together with the elevated levels of malondialdehyde. Determination of the bioaccumulation of arsenic in the liver tissues of using hydride generation atomic absorption spectrophotometry (HG-AAS) revealed an increased As(III) accumulation in the fishes exposed to arsenic whereas the arsenic level in the control and bacteria treated fishes were found below the detectable limit. In conclusion, this study presents the strategies of bacterial arsenic removal with possible directions for future research.
砷是一种广泛存在于环境中的有毒类金属，从受污染的水中去除砷已成为一项全球性挑战。在这方面利用细菌找到了解决这一问题的可行办法。在本研究中，根据其砷去除效率选择了抗砷细菌菌株As-9。对用该细菌处理过的水中的砷进行定量分析表明，该细菌能在不到20小时内高效去除高达99%的砷。为了揭示这种细菌在从水中去除砷以及保护鱼类免受砷的有害影响方面可能产生的作用，我们对淡水鱼开展了一系列研究。观察到，放入经细菌处理的水中的鱼未表现出砷中毒症状，其氧化损伤减轻，而暴露于砷的鱼的氧化应激显著增加（P<0.05），同时丙二醛水平升高。用氢化物发生原子吸收分光光度法（HG-AAS）测定鱼肝脏组织中的砷生物累积量，结果显示暴露于砷的鱼体内As(III)累积量增加，而对照鱼和经细菌处理的鱼体内的砷水平低于检测限。总之，本研究提出了细菌去除砷的策略以及未来研究的可能方向。
