滇池沉积物中好氧氨氧化细菌群落多样性研究

Community Diversity of Aerobic Ammonium-oxidizing Bacteria in Sediments of Dianchi Lake

从滇池沉积物中提取好氧氨氧化细菌(aerobic ammonium-oxidizing bacteria,AOB)的DNA,通过构建硝化作用氨单加氧酶基因(amo A)文库并划分操作分类单元(OTU)的方法,揭示好氧氨氧化细菌群落结构多样性。获得了80个amo A基因克隆,利用Mothur软件将相似度不小于97%的序列归为1个OTU,共得到22个OTUs,其中OTU1、OTU2、OTU3单元最大,分别包含了27、12、9条序列。对22个OTUs的代表序列进行系统发育分析表明,其序列都属于变形杆菌的β-亚纲,分布于亚硝化螺菌属、亚硝化弧菌属、亚硝化单胞菌属、亚硝化叶菌属4个属;优势种群为Nitrosomonas europaea的近缘种,尚未被描述过。

The clone libraries of ammonium monooxygenase encoding gene （amoA） in the sediments of Dianchi lake were constructed and grouped into the operational taxonomic units （OTUs） to determine the community diversity of aerobic ammonium-oxidizing bacteria （AOB）. A total of 80 sequences were obtained from Dianchi lake. 22 OTUs from Dianchi lake were grouped respectively based on a 3 % amoA gene sequence distance cutoff with the Mothur program. The largest groups were OTU1, OTU2 and OTU3 which consisted of 27, 12, 9 sequences respectively. Representative sequences of 22 OTUs were determined and a phylogenie tree was constructed. Phylogenetie analysis with the aligned sequences showed that the amoA sequences from Dianchi lake were all in the β-subdivision of Proteobacteria. These sequences belonged to genus Nitrosovibrio, Nitrosospira, Nitrosomonas and Nitrosolobus. The dominated β-AOB populations was the closely related species of Nitrosomonas europaea which had not been described.