黄土高原沙棘根际氢氧化细菌的分离与种属分布

目的研究陕西黄土高原沙棘(Hippophae rhamnoides)根际氢氧化细菌种属分布。方法利用持续通H2的气体循环培养体系分离纯化细菌。通过TTC(2,3,5-氯化三苯基四氮唑)试验和氧化H2能力测定筛选含有氢化酶的菌株。根据其培养特征、形态特征和生理生化特征进行菌株鉴定。用16S rRNA基因序列分析法对氧化氢能力最强的优势菌株构建系统发育树。结果筛选出6株菌初步确定为氢氧化细菌,并划分为4个属:芽孢杆菌属(Bacillus)、气单胞菌属(Aeromonas)、假单胞菌属(Pseudomonas)和微球菌属(Micrococcus)。其中菌株FS2的16S rRNA基因序列(Gen-Bank登录号为GU084156)与芽孢杆菌属相似性为99%,在系统发育树上位于同一分支,因此将菌株FS2归为芽孢杆菌属(Bacillus)。结论说明氢氧化细菌在自然界分布广泛,并为分析氢氧化细菌的种群结构特征提供基础材料。

The solation,identification and phylogeny of hydrogen-oxidizing bacteria from Hippophae rhamnoides rhizosphere in the Loess Plateau of China

Aim To study hydrogen oxidizing bacteria′s genera from Hippophae rhamnoides rhizosphere in the Loess Plateau in Shaanxi Province of China.Methods Gas-cycle incubation system was used to isolate bacteria strains.The strains containing hydrogenase activity were selected by TTC(triphenyltetrazo-lium chloride) test and hedrogen-oxidizing ability of the strains.These strains are identified based on their morphological,physiological and biochemical characteristics.16S rRNA gene sequence analysis is used to built the phylogenic tree of the strain which has strongest hedrogen-oxidizing ability.Results Six strains were identified as hydrogen oxidizing bacteria initially and identified as members of genera Bacillus,Aeromonas,Pseudomonas and Micrococcus,respectively.The 16S rRNA gene sequence analysis suggested that the strain FS2(GenBank accession number GU084156) was clustered together with Bacillus in phylogenetic tree,with the sequence similarity more than 99%.Conclusion The experiments show that hydrogen-oxidizing bacteria distribute widely in nature,providing base material to analyze the structure of population of hydrogen-oxidizing bacteria.