汾河下游水体nirS型反硝化细菌群落组成与无机氮关系

Community Composition of nir S-type Denitrifying Bacteria in the Waters of the Lower Reaches of the Fenhe River and Its Relationship with Inorganic Nitrogen

为了探明汾河下游水体中nir S型反硝化细菌群落结构组成及其与无机氮的相互影响关系,在分析河流9个水样水质指标的基础上,运用Illumina高通量测序技术对水样中的nir S型反硝化细菌群落结构和多样性进行诊断,并进行统计分析,解析水体nir S型反硝化细菌群落与无机氮之间的关系.结果表明,汾河下游无机氮污染严重,整体水质为Ⅴ类水标准.Shannon指数变化范围为3. 36~7. 54,说明该流域反硝化细菌群落多样性较高;水体中主导菌属相对丰度占总群落的89. 8%,分别为红细菌属Rhodobacter、假单胞菌属Pseudomonas和陶厄氏菌属Thauera;DO、p H值及无机氮含量是影响汾河下游水体反硝化细菌群落的主要因素;优势菌属红细菌属Rhodobacter、陶厄氏菌属Thauera与NO3^--N、NO2^--N呈负相关,与NH4^+-N呈正相关,稷山、河津和入黄口这3处的主要菌属假单胞菌属Pseudomomas与NO3^--N、NO2^--N呈负相关,与NH4^+-N呈正相关.汾河下游水体中nir S型反硝化细菌中的主要菌属促进了反硝化作用,对降低水体中硝态氮的含量有一定的影响.

In order to assess the waters of the lower reaches of the Fenhe River and the interaction with inorganic nitrogen,Illumina high-throughput sequencing technology was used to analyze samples based on the analysis of water quality indicators of nine rivers. The community structure and diversity of nirS-type denitrifying bacteria was diagnosed and statistical analysis was carried out to analyze the relationship between these communities and inorganic nitrogen content. The results show that the lower reaches of the Fenhe River are seriously polluted with inorganic nitrogen and the overall water quality standard was classified as V. The range of calculated Shannon index values was 3. 36-7. 54,indicating that the diversity of the denitrifying bacterial community is high in this basin. The relative abundance of the dominant genera represented 89. 8% of the total community,which included Rhodobacter,Pseudomonas,and Thauera. The DO,pH,and inorganic nitrogen content were the main factors affecting the denitrifying bacterial community in the lower reaches of the Fenhe River. The dominant genus,Rhodobacter,and the genus Thauera were negatively correlated with NO3^--N and NO2^--N,and were positively correlated with NH4^+-N. Pseudodomomas was the dominant genus in the Jishan and Hejin areas,and in the Fenhe River feeding into the Yellow River,and was negatively correlated with NO3^--N and NO2^--N but positively correlated with NH4^+-N. The dominant genera of nirS-type denitrifying bacteria in the lower reaches of the Fenhe River promote denitrification and play a role in reducing the content of nitrate nitrogen in the water.