中文摘要：

利用气体循环培养体系从陕西乾县HUP—豆科植物紫花苜蓿（Medicago sativa）根际土壤中分离获得37株细菌.菌株氧化氢能力测定结果表明,8株菌氧化氢和自养生长能力较强,初步确定为氢氧化细菌类群;根据其形态特征、培养特征和生理生化特性,鉴定为7个不同属：假单胞菌属（Pseudomonas）、邻单胞菌属（Plesiomonas）、脂肪杆菌属（Pimelobacter）、黄色杆菌属（Xanthobacter）、勒米诺氏菌属（Leminorella）、地杆菌属（Terrabacter）和稀有杆菌属（Rarobacter）;其中氧化氢能力最强的优势菌株WMQ-7 16S rDNA序列（GenBank登录号为EU807744）长度为1451bp,GC含量为53.8%,其核苷酸序列与假单胞菌属同源性高于99%,在系统发育树上位于同一分支,将WMQ-7菌株鉴定为假单胞菌属（Pseudomonas）.图2表5参16

英文摘要：

Gas-cycle incubation system was used to enrich the Medicago sativa rhizosphere soil collected in Shaanxi Province,China and 37 strains of bacteria were isolated.Among them,8 stains had stronger ability to oxidize hydrogen and could grow chemolithoautotrophically,so they were preliminarily identified as hydrogen-oxidizing bacteria.According to their cells,colony forms and biochemical characteristics,the 8 strains were identified as Pseudomonas,Plesiomonas,Pimelobacter,Xanthobacter,Leminorella,Terrabacter and Rarobacte. Strain WMQ-7 had the strongest ability to oxidize hydrogen, and its 16S rDNA sequence （GenBank accession number EU807744） was 1 451 bp and GC content was 53.8%. Strain WMQ-7 was clustered together with Pseudomonas in phylogenic tree, with the sequence identity of 99%. Therefore, strain WMQ-7 was identified as Pseudomonas. Fig 2, Tab 5, Ref 16