Sun Hai-mei, Bai Jiao-jiao, Sun Wei-ling, Shao Jun
Key Laboratory for Urban Habitat Environmental Science and Technology, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055, China.
Huan Jing Ke Xue. 2012 Aug;33(8):2691-700.
Microbial community structure and biomass in river water can reflect the situation of water quality in some extent. Nitrogen removal was mainly achieved by the nitrification and denitrification processes, and ammonia oxidation catalyzed by ammonia-oxidizing bacteria (AOB) is the first and rate-limiting step of nitrification. To explore the AOB community structure and biomass in nitrogen polluted river, water samples were collected from Buji River (Shenzhen) in wet season. Quantification of 16S rRNA copy numbers of total bacteria and AOB were performed by real-time PCR, and the microbial community structures were studied by denaturing gradient gel electrophoresis (DGGE). The results showed that the number of total bacterial 16S rRNA changed from 4.73 x 10(10) - 3.90 x 10(11) copies x L(-1) in the water samples. The copy numbers of AOB varied from 5.44 x 10(6) - 5.96 x 10(8)copies x L(-1). Redundancy discrimination analysis (RDA) showed that the main factors affecting the structure and the numbers of bacteria were different. For total bacteria, nitrate influenced the biomass significantly (P < 0.05) while nitrogen and heavy metals (Mn and Zn) were the main factors affecting the microbial community structures (P < 0.05). For AOB, ammonia and Zn were the main factors influencing the biomass while ammonia nitrogen and heavy metals (Mn and Zn) were the main factors affecting the microbial community structures. 16S rDNA sequences from the water samples indicated that the bacteria generally belonged to Epsilon-Proteobacteria, Gamma-Proteobacteria, Beta-Proteobacteria, and Delta-Proteobacteria. Nitrosomonas sp. and Nitrosospira sp. were the main AOB. Cluster analysis showed that water pollution in downstream resulted in evident difference in microbial community structure between upstream and downstream water samples.
河水中微生物群落结构和生物量在一定程度上能够反映水质状况。氮的去除主要通过硝化和反硝化过程实现，而由氨氧化细菌（AOB）催化的氨氧化是硝化作用的第一步且为限速步骤。为探究氮污染河流中AOB的群落结构和生物量，在雨季从深圳布吉河采集了水样。通过实时荧光定量PCR对总细菌和AOB的16S rRNA拷贝数进行定量，并用变性梯度凝胶电泳（DGGE）研究微生物群落结构。结果表明，水样中总细菌16S rRNA数量在4.73×10¹⁰ - 3.90×10¹¹拷贝·L⁻¹之间变化。AOB的拷贝数在5.44×10⁶ - 5.96×10⁸拷贝·L⁻¹之间。冗余判别分析（RDA）表明，影响细菌结构和数量的主要因素不同。对于总细菌，硝酸盐显著影响生物量（P < 0.05），而氮和重金属（锰和锌）是影响微生物群落结构的主要因素（P < 0.05）。对于AOB，氨和锌是影响生物量的主要因素，而氨氮和重金属（锰和锌）是影响微生物群落结构的主要因素。水样的16S rDNA序列表明，细菌一般属于ε-变形菌纲、γ-变形菌纲、β-变形菌纲和δ-变形菌纲。亚硝化单胞菌属和亚硝化螺菌属是主要的AOB。聚类分析表明，下游的水污染导致上下游水样的微生物群落结构存在明显差异。
