一株厌氧反硝化细菌的分离鉴定与砷耐受功能研究  

Isolation,Identification and Functional Study of an Arsenic-resistant Anaerobic Denitrifying Bacterium

作　　者：冯纪龙 陈晓明 刘紫薇 罗锋[2] FENG Jilong;CHEN Xiaoming;LIU Ziwei;LUO Feng(School of Environmental Studies,China University of Geosciences(Wuhan),Wuhan 430078,China;School of Medicine,Jianghan University,Wuhan 430056,China)

机构地区：[1]中国地质大学(武汉)环境学院,湖北武汉430078 [2]江汉大学医学院,湖北武汉430056

出　　处：《安全与环境工程》2021年第4期95-101,109,共8页Safety and Environmental Engineering

基　　金：国家自然科学基金项目(42472219)。

摘　　要：稻米和蔬菜是人体摄入的主要食物来源,由于人的活动造成了稻米和蔬菜中砷与硝酸盐超标。摄入的砷污染稻米与硝酸盐超标蔬菜会经过人体消化系统被胃肠道吸收并释放部分砷与硝酸盐产物,人体肠道对砷与硝酸盐具有一定的解毒作用,其中肠道微生物发挥着重要作用。从人类新鲜粪样中富集与分离出一株厌氧反硝化菌株CD14-2,通过比对与分析其16S rRNA序列,确定该菌株属于肠杆菌科埃希氏菌属(Escherichia),并对其硝酸盐还原酶基因(nitrate reductase,Nar)进行了同源性分析,进一步探究了菌株CD14-2在乳酸钠作为碳源下的反硝化速率和对不同碳源的利用情况以及菌株CD14-2与砷的相互作用。结果表明:反硝化菌株CD14-2能够在48 h内将10 mM硝酸盐氮还原为近9 mM亚硝酸盐氮,并能够利用多种碳源,在高砷浓度中生长且具有反硝化功能;当砷浓度不超过1 mM时,该菌株的反硝化功能基本未受影响,当砷浓度超过1 mM时,会对该菌株的反硝化能力起到抑制作用,且其抑制效果与砷浓度呈正相关关系。Rice and vegetables are the main food sources for human.Due to human activities,the content of arsenic and nitrate in rice and vegetables are sometimes beyond the standard.Arsenic and nitrate in rice and vegetables can be absorbed by the gastrointestinal tract through digestive system of human,releasing some of the arsenic and nitrate products.However,human gastrointestinal tract has some detoxification abilities,among which gut microorganisms play an important role.In this study,a strain of aerobic denitrifying bacteria CD14-2 from human fecals has been obtained.The homology analysis of the 16 S rRNA and nitrate reductase genes show that CD14-2 belongs to genus Escherichia,family Enterobacteriaceae.Moreover,the study further conducts homology analysis of nitrate reductase gene Nar,and investigats the denitrification rate and utilization of different carbon sources for CD14-2 strain with sodium lactate as carbon source,and the interaction between CD14-2 strain and arsenic.The results show that the efficiency of NO_(3)^(-)-N reduction under anaerobic condition within 48 h is up to 90%,and the strain can ultilize multiple Carbon-source.CD14-2 can grow in high arsenic concentration.When the arsenic concentration is above 1 mM,the denitrification capacity of the strain will be inhibited.Additionally,the arsenic concentration is positively correlated with the inhibition.

关 键 词：反硝化细菌 耐砷菌 埃希氏菌属 硝酸盐还原酶 抑制 

分 类 号：X17[环境科学与工程—环境科学]