中文摘要：

从砷污染土壤中富集砷抗性细菌，在厌氧环境中进行培养，观察其对砷的还原能力。结果表明1在21h之内，As（V）就被完全还原为As（Ⅲ）；培养72h后，培养基中出现黄色沉淀，采用X射线衍射分析（XRD）和扫描电镜．能谱分析（SEM—EDS）技术对沉淀进行分析表明，沉淀主要是以3种晶型存在的硫化砷（AsS）；培养150h后，大约有65％的As以上述沉淀的方式从溶液中移除。此外，本文还采用了构建16SrDNA文库的方式对该体系中的微生物种群进行分析，利用RFLP技术对16SrDNA片段进行分型，共得到72个操作单元类型（OTU），其中6个OTU占了库容的51％，从这6个OTU中各选取1个克隆进行测序，结果表明，富集到的砷还原细菌属于喜热菌属（Caloramator）、梭菌属（Clostridium）和杆菌属（Bacillus）。

英文摘要：

Arsenic （As） -resistance bacteria were enriched from an As-contaminated soil and cultured in anaerobic environment, aimed to study their arsenate reduction capability and microbial diversity. Within 21 h incubation, arsenate was completely reduced to arsenite; after 72 h incu- bation, yellow precipitates formed; and after 150 h incubation, about 65% of soluble arsenic was removed. SEM-EDS and XRD analyses revealed that the yellow precipitates were mainly of three kinds of AsS crystalloid. The microbial diversity in the culture was investigated by 16S rDNA-dependent molecular phylogeny, and a near-full-length 16S rDNA gene clone library was constructed. 197 clones were analyzed by using RFLP, and a total of 72 OTUs were obtained, among which, six OTUs occupied 51% of the volume. One clone from each of the six OTUs was selected for sequencing, and it was indicated that the enriched As-reducing bacteria belonged to Caloramator , Clostridium , and Bacillus.