中文摘要：

目的：研究含arsH基因抗砷微生物的多样性。方法：从NCBI数据库中收集95条arsH基因序列,通过Clustal W1.83、Mega3.0、DOTUR软件分别对95条序列进行多序列比对、构建系统发育树、稀释曲线等分析。结果：这些包含arsH基因的菌株分别归属于α-变形杆菌纲（约40%）,γ-变形杆菌纲（35%）,β-变形杆菌纲（22%）,以及蓝细菌（3%）。在涉及的14个科当中,Rhizobiales所占比例最高（29%）;Burkholderiales次之（22%）;Pseudomonadales和Enterobacteriales占较少的比例,分别为18%和11%。针对数据库已有数据分析显示,含有arsH基因的微生物约89%分布在陆地,6%分布在海洋,还有5%在陆地海洋均有分布。陆地中占总比例的24%分布于土壤中;21%分布于矿山、地下水、气田、油田、受污染环境、矿坑水、淡水等环境中;约1%为植物共生菌,26%为病原微生物。结论：该基因在不同的物种之间存在水平基因转移,目前对于含arsH基因的抗砷微生物的筛选和分离工作还远远不够。

英文摘要：

Objective：To investigate the diversity of arsH genes involved in arsenic-resistant bacteria.Methods：The arsH genes were retrieved from Genbank database.Program Clustal W 1.83,Mega 3.0 and DOTUR were used to analyse multi-alignment,phylogenetic and rarefaction.Resaults：All the arsH-containing communities are grouped into α-Proteobacteria（40%）,γ-Proteobacteria（35%）,β-Proteobacteria（22%）,and cyanobacteria（3%）.Rhizobiales accounts for the highest proportion about29%,Burkholderiales,Pseudomonadales and Enterobacteriales account for less proportion about 22%,18% and 11%,respectively.Research on source environments of cultivation-dependent arsH-containing bacteria revealed that about 89% distribute in terrestrial,6% in ocean and 5% cosmopolitan.And about 24% of global distribution in terrestrial distribute in soil,21% distribute in mine,underground water,gass plant,oil field,contaminated environment,acid mine drainage and fresh water.1% is plant symbiosis,and 26% is pathogens.Conclusions：The horizontal gene transfer（HGT） is occurred among different species.Rarefaction curves indicate the current effort on cultivation-dependent arsH containing bacteria was still inadequate.