二价铁氧化对铁锰循环功能微生物活性的影响及机制  

Effect and Mechanism of Fe(Ⅱ)Oxygenation on Activities of Iron and Manganese Cycling Functional Microbes

作　　者：屈婧祎 童曼[1] 袁松虎[1] Qu Jingyi;Tong Man;Yuan Songhu(State Key Laboratory of Biogeology and Environmental Geology,China University of Geosciences,Wuhan 430078,China)

机构地区：[1]中国地质大学生物地质与环境地质国家重点实验室,湖北武汉430078

出　　处：《地球科学》2021年第2期632-641,共10页Earth Science

基　　金：国家自然科学基金青年基金项目(No.41703113)。

摘　　要：地质微生物是沉积环境中铁、锰氧化还原循环的主要驱动因子,铁锰共存环境中二价铁氧化对不同铁、锰循环功能微生物活性的影响差异和机制尚不清楚.以铁还原菌Shewanella oneidensis MR-1、铁氧化菌Pseudogulbenkiania sp.strain 2002、锰氧化菌Pseudomonas putida MnB1和Leptothrix discophora SS-1作为代表性的铁、锰循环功能微生物,利用平板计数、荧光显微镜等手段探究了Fe(Ⅱ)氧化对功能微生物活性的影响差异及机制.结果表明0.05 mM Fe^(2+)氧化60 min可使MR-1和MnB1的活菌数量降低4~5个数量级,SS-1及S.2002无显著失活.Fe(Ⅱ)氧化产生的吸附态·OH和胞内·OH是细菌失活的主要原因,胞外H2O2、胞外游离态·OH和三价铁氧化物是细菌失活的次要原因,SS-1及S.2002产生了氧化应激反应,成功抵御了活性氧化物种.Geologic microorganisms are the main factors driving the redox cycling of iron and manganese in sedimentary environment.The effect and mechanism of Fe(Ⅱ)oxygenation on the activities of different iron and manganese cycling functional microbes remain unexplored.In this study,it used Shewanella oneidensis MR-1,Pseudogulbenkiania sp.strain 2002,Pseudomonas putida MnB1,Leptothrix discophora SS-1 as the representative iron and manganese cycling functional microbes,it investigated the difference in effect and mechanisms of Fe(Ⅱ)oxygenation on the activities of these four bacteria.Results show that the living cell counts of MR-1 and MnB1 decreased by 4-5 lg upon 60 min oxygenation of 0.05 mM Fe(Ⅱ),but no significant inactivation of SS-1 and S.2002 was observed.The surface absorbed·OH and intracellular·OH produced from Fe(Ⅱ)oxygenation were the dominant reasons for bacteria inactivation,the extracellular H2O2,extracellular dissolved·OH and Fe(Ⅲ)oxides are minor causes for bacteria inactivation.SS-1 and S.2002 show oxidative stress responses during Fe^(2+)oxygenation,which helped to resist the damage of reactive oxygen species.

关 键 词：二价铁 铁锰循环 地质微生物 氧化还原波动 生物地球化学 

分 类 号：P641.3[天文地球—地质矿产勘探]