Cheng Zhanbing, Yang Jiangke, Li He, Zhu Bing, Chen Xiangjun, Yan Yunjun
Key Laboratory of Molecular Bio-physics, Ministry of Education, China.
Wei Sheng Wu Xue Bao. 2011 May;51(5):667-75.
The study aims to investigate the phylogeny diversity of the denitrification bacteria communities in the sediments of the eutrophic East Lake, Wuhan based on nitrite reductase gene (nirS) restriction fragment length polymorphism (RFLP) method and sequencing analysis, and to analyse community variation according to the environment parameters.
We collected the sediment samples from the four typical sub-lake of East Lake in Wuhan, Guozheng Lake, Tangling Lake, Tuan Lake and Miao Lake, and measured the environmental parameters appropriately. After extracted the genomic DNA from the sediment, four nirS gene clone libraries were successfully constructed. The operation taxonomy units (OTUs) were determined by RFLP method and the representative fragment of every OTU was sequenced. The diversity, richness and evenness statistics of the NirS-like communities were calculated by using DOTUR software. Neighbor-joining phylogenetic tree was constructed basing on the amino acid sequences of NirS from the East Lake sediments and reference sequences retrieved from the GenBank database. The relationship between tested NirS communities and the references from different environments was also discussed.
Environmental parameters showed that Miao Lake sediment contains the highest amount of total nitrogen (TN) and NH4+ -N, while the Tuan Lake sediments contains the lowest amount. Among the four sub-lakes, Tuan Lake harbours the highest diversity and richness of NirS-like denitrifiers, while the denitrifiers in Miao Lake was the lowest. Phylogenic analyses suggested that sedimentary NirS-like denitrifiers in the East Lake could be distributed into three groups, Group I to III. Group I accounts for 67.7% of all tested communities. Eighty-one percent of sequences from Guozheng Lake were clustered into Group I, while 67.7% of sequences from Miao Lake were clustered into Group II. Comparative analysis of communities from East Lake and artificial wetland found there are phylogenetically related.
There are diverse and abundant NirS-like denitrifiers inhabited in the sediments of East Lake, Wuhan. The diversity indices and spatial distribution of these communities are affected by the content of TN, NH4- and NO3- nutrients in the sediments.
本研究旨在基于亚硝酸还原酶基因（nirS）限制性片段长度多态性（RFLP）方法和测序分析，调查武汉富营养化的东湖沉积物中反硝化细菌群落的系统发育多样性，并根据环境参数分析群落变化。
我们从武汉东湖的四个典型子湖，郭郑湖、汤林湖、团湖和苗湖采集了沉积物样本，并适当测量了环境参数。从沉积物中提取基因组DNA后，成功构建了四个nirS基因克隆文库。通过RFLP方法确定操作分类单元（OTU），并对每个OTU的代表性片段进行测序。使用DOTUR软件计算类NirS群落的多样性、丰富度和均匀度统计数据。基于东湖沉积物中NirS的氨基酸序列和从GenBank数据库检索的参考序列构建邻接系统发育树。还讨论了测试的NirS群落与不同环境参考之间的关系。
环境参数表明，苗湖沉积物中的总氮（TN）和NH4 + -N含量最高，而团湖沉积物中的含量最低。在四个子湖中，团湖的类NirS反硝化菌多样性和丰富度最高，而苗湖中的反硝化菌最低。系统发育分析表明，东湖沉积物中的类NirS反硝化菌可分为三组，第一组至第三组。第一组占所有测试群落的67.7%。来自郭郑湖的81%的序列聚类到第一组，而来自苗湖的67.7%的序列聚类到第二组。对东湖和人工湿地群落的比较分析发现它们在系统发育上相关。
武汉东湖沉积物中栖息着多样且丰富的类NirS反硝化菌。这些群落的多样性指数和空间分布受沉积物中TN、NH4-和NO3-养分含量的影响。
