作 者：
周武先;段媛媛;游景茂;赵诗晨;卢超;罗孝荣;张美德
单 位：
湖北省农业科技创新中心中药材研究分中心;南京农业大学资源与环境科学学院;作物遗传与种质创新国家重点实验室;湖北省农业科学院中药材研究所
关键词：
砷;微生物;三价砷氧化;反硝化;砷污染水稻土;修复
摘 要：
为砷(As)污染水稻土的微生物修复提供宝贵的菌种资源以及探索淹水条件下砷氧化菌修复As污染水稻土的可能机理。从全国各地As污染水稻土中筛选砷氧化菌,并进行分子鉴定、生理生化研究以及As污染土壤的修复试验。结果共计分离出6株具有砷氧化功能的菌株,其中一株扩增出砷氧化酶基因(aioA),命名为DWY-1,来自黄石As污染水稻土,经鉴定为中华根瘤菌属(Sinorhizobium sp.),革兰氏染色显示为阴性,属于兼性自养和兼性厌氧菌。在好氧条件下和厌氧条件下菌株DWY-1均可以将三价砷[As(Ⅲ)]氧化为五价砷[As(Ⅴ)],且厌氧条件下可将As(Ⅲ)氧化与硝酸盐还原过程进行偶联并从中获得能量用于自身的生长。将菌株DWY-1接种到淹水As污染水稻土中,培育14 d后,孔隙水和土壤底泥中磷酸可提取态的As(Ⅲ)含量与对照相比分别降低73.0%和80.0%,总As含量分别降低32.6%和32.9%。综上,菌株DWY-1可作为修复As污染水稻土的潜在菌种资源;在淹水水稻土中,砷氧化菌可以耦合厌氧As(Ⅲ)氧化与硝酸盐还原过程并从中获得能量进行生长,此过程可作为修复As污染水稻土的途径之一。
译 名：
Isolation and identification of arsenite oxidizing bacterium DWY-1 and the possible mechanism involved in remediating arsenic-contaminated paddy soil
作 者：
ZHOU Wu-xian;DUAN Yuan-yuan;YOU Jing-mao;ZHAO Shi-chen;LU Chao;LUO Xiao-rong;ZHANG Mei-de;Institute of Chinese Herbal Medicines, Hubei Academy of Agricultural Sciences;Chinese Herbal Medicine Subcenter of Hubei Agricultural Science and Technology Innovation Centre;College of Resources and Environmental Sciences, Nanjing Agricultural University;State Key Laboratory of Crop Genetics and Germplasm Enhancement;
单 位：
ZHOU Wu-xian%DUAN Yuan-yuan%YOU Jing-mao%ZHAO Shi-chen%LU Chao%LUO Xiao-rong%ZHANG Mei-de%Institute of Chinese Herbal Medicines, Hubei Academy of Agricultural Sciences%Chinese Herbal Medicine Subcenter of Hubei Agricultural Science and Technology Innovation Centre%College of Resources and Environmental Sciences, Nanjing Agricultural University%State Key Laboratory of Crop Genetics and Germplasm Enhancement
关键词：
arsenic;;microorganism;;arsenite oxidation;;denitrification;;arsenic-contaminated paddy soil;;remediation
摘 要：
The aim of this study is to identify a strain for microbial remediation of arsenic(As)-contaminated paddy soil and explore the possible mechanism of arsenite[As(Ⅲ)] oxidizing bacteria in remediating As-contaminated paddy soil under flooded conditions. In this study,some As(Ⅲ)oxidizing bacteria were isolated from the As-contaminated paddy soils collected from different areas in China. We carried out molecular identification, physiological and biochemical analyses on these bacteria, and then used them in remediation experiments on As-contaminated soil.Six strains capable of oxidizing As(Ⅲ)were isolated. A novel chemoautotrophic As(Ⅲ)-oxidizing bacterium strain, designated as DWY-1, was isolated from an As-contaminated paddy soil in Huangshi City. The physiological and biochemical characteristics showed that the strain DWY-1 was a facultative autotrophic anaerobe, Gram-negative, and belonged to the genus Sinorhizobium. This bacterium could utilize the energy generated from the oxidation of As(Ⅲ)to arsenate[As(Ⅴ)] using O2 or NO-3 as the respective electron acceptor for growth under both aerobic and anaerobic conditions. After the addition of cells of strain DWY-1 into the flooded As-contaminated paddy soil for 14 days, the content of As(Ⅲ)in pore water and the phosphoric acid-extractable fraction decreased by 73.0% and 80.0%, respectively. In these samples, the total As content decreased by 32.6% and 32.9%, respectively. In summary, the strain DWY-1 can be a potential resource for the remediation of As-contaminated paddy soil. In the flooded paddy soil, As(Ⅲ) oxidizing bacteria can couple anaerobic As(Ⅲ)oxidation with nitrate reduction and obtain energy from these biological processes for growth. Thus, As(Ⅲ)oxidation me.diated by strain DWY-1 is considered as one of the effective ways to remediate As-contaminated soil.
