Phylogenetic diversity of nitrogen-fixing bacteria and the nifH gene from mangrove rhizosphere soil
Phylogenetic diversity of nitrogen-fixing bacteria and the nifH gene from mangrove rhizosphere soil
复制标题
红树林根际土壤固氮细菌和nifH基因的系统发育多样性
DOI：
10.1139/w2012-016
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发表时间：
2012-04-01
影响因子：
2.8
通讯作者：
Li, Youguo
中科院分区：
文献类型：
--
作者：
Liu, Jianyin;Peng, Mengjun;Li, Youguo
从东寨港国家级红树林自然保护区的3个红树林植物根际土壤样品中分离到9株固氮细菌。大多数菌株属于γ-变形杆菌假单胞菌，表明这些环境构成了有利的生态位，这样丰富的固氮细菌。利用土壤DNA提取和PCR-克隆-测序的方法，对135个克隆进行限制性片段长度多态性（RFLP）分析，鉴定出27个独特的nifH序列多态性类型，其中大部分与未培养细菌的序列密切相关。利用nifH系统发育树，结合GenBank中其它红树林生态系统的nifH序列，对红树林固氮细菌的多样性进行了分析。不同土壤样品nifH多样性存在差异，红树林生态系统中nifH具有不同的生态地球化学特征。当比较不同的红树林生态系统时，来自特定位点的nifH基因序列倾向于聚为单独的组。研究结果为我们了解红树林生态系统固氮生物群落多样性提供了有趣的数据和新的信息。
Nine types of nitrogen-fixing bacterial strains were isolated from 3 rhizosphere soil samples taken from mangrove plants in the Dongzhaigang National Mangrove Nature Reserve of China. Most isolates belonged to Gammaproteobacteria Pseudomonas, showing that these environments constituted favorable niches for such abundant nitrogen-fixing bacteria. New members of the diazotrophs were also found. Using a soil DNA extraction and PCR-cloning-sequencing approach, 135 clones were analyzed by restriction fragment length polymorphism (RFLP) analysis, and 27 unique nifH sequence phylotypes were identified, most of which were closely related to sequences from uncultured bacteria. The diversity of nitrogenfixing bacteria was assessed by constructing nifH phylogenetic trees from sequences of all isolates and clones in this work, together with related nifH sequences from other mangrove ecosystems in GenBank. The nifH diversity varied among soil samples, with distinct biogeochemical properties within a mangrove ecosystem. When comparing different mangrove ecosystems, the nifH gene sequences from a specific site tended to cluster as individual groups. The results provided interesting data and novel information on our understanding of diazotroph community diversity in the mangrove ecosystems.