Shewanella oneidensis MR-1对Cr(Ⅵ)的还原及其影响因素  

Reduction of Cr(Ⅵ) by Shewanella oneidensis MR-1 and its influencing factors

作　　者：杜艳影 刘小红[1,2] 李劲 李磊明 司友斌[1] DU Yan-ying;LIU Xiao-hong;LI Jing;LI Lei-ming;SI You-bin(Anhui Province Key Laboratory of Farmland Ecological Conservation and Pollution Prevention,School of Resources and Environment,Anhui Agricultural University,Hefei 230036,China;Key Laboratory of Soil Environment and Pollution Remediation,Institute of Soil Science,Chinese Academy of Sciences,Nanjing 210008,China)

机构地区：[1]农田生态保育与污染防控安徽省重点实验室,安徽农业大学资源与环境学院,安徽合肥230036 [2]中国科学院南京土壤研究所土壤环境与污染修复重点实验室,江苏南京210008

出　　处：《中国环境科学》2018年第7期2740-2745,共6页China Environmental Science

基　　金：国家重点研发计划课题(2017YFD0801102);国家科技支撑计划课题(2015BAD05B04-02);中国科学院土壤环境与污染修复重点实验室课题(SEPR2017-07);安徽省重点项目(KJ2016A228)

摘　　要：在实验室纯培养条件下,探讨厌氧体系中Shewanella oneidensis MR-1对Cr(Ⅵ)的还原能力,采用扫描电镜(SEM)-能谱(EDS)、X射线光电子能谱(XPS)等方法进行表征.结果表明,S.oneidensis MR-1介导下不同浓度Cr(Ⅵ)的生物转化与微生物对铬的耐受特性密切相关,低浓度Cr(Ⅵ)对其生长影响不大,高浓度时细菌生长则受到抑制,进而抑制Cr(Ⅵ)的还原率;菌株对Cr(Ⅵ)的还原作用随着接种菌悬液量的增加而增强;菌株最适生长p H值为中性,弱碱性环境比酸性环境更有利于菌株对Cr(Ⅵ)的还原;增加Fe(III)的量会加快Cr(Ⅵ)完全还原的速率.通过SEM-EDS和XPS分析,在对Cr(Ⅵ)进行处理5d后,菌体表面有Cr(Ⅵ)和Cr(III)两种形态存在,证实S.oneidensis MR-1在对Cr(Ⅵ)进行还原的同时也伴有少量的吸附作用.微生物还原为环境中Cr(Ⅵ)的去除以及解毒提供了一种有效的方法.The ability of Shewanella oneidensis MR-1 to reduce Cr(VI)was investigated by pure culture under anaerobic condition in laboratory.The characterics of Cr(VI)reduction by S.oneidensis MR-1 was studied by scanning electron microscopy(SEM)equipped with an energy dispersive spectrometer(EDS)and X-ray photoelectron spectroscopy(XPS).The results showed that the bioreduction of Cr(VI)at different initial concentrations was closely related to the tolerance of bacterial strains to chromium.Cr(VI)at low concentration had little effect on the strains growth.Cell growth was inhibited at high Cr(VI)concentration,thereby inhibiting the reduction of Cr(VI).The reduction of Cr(VI)increased with increasing the amount of strains inoculum.The optimum pH of the strains growth was neutral,and the weakly alkaline environment was more conducive to the Cr(VI)reduction than the acidic environment.The increasing amount of Fe(III)accelerated the rate at which Cr(VI)was completely reduced.The results of SEM-EDS and XPS analysis showed that Cr(VI)and Cr(III)existed on the surface of cells after treatment with Cr(VI)for 5days,which confirmed that Cr(VI)reduction by S.oneidensis MR-1was at the same time also accompanied by a small amount of Cr(VI)adsorption.Microbial reduction provides an effective method for the removal and detoxification of Cr(VI)in the environment.

关 键 词：CR(VI) SHEWANELLA oneidensis MR-1 生物还原 X射线光电子能谱 

分 类 号：X172[环境科学与工程—环境科学]