芜湖城市内河水体微生物群落结构特征及其影响因素

Microbial community structure and its influencing factors in urban river water in Wuhu

为研究夏末秋初芜湖城市内河水质波动原因,在综合考虑河段周边土地利用类型、污染源排放等因素的基础上,论文选择芜湖三条代表性城市内河河段(中央城河段、汇成河段、中山南路河段)作为研究对象,布设了18个监测断面,分析了pH、溶解氧(DO)、电导率(EC)、氨氮(NH3-N)和总磷(TP)以及叶绿素a(Chla)等水质指标,采用16S rRNA高通量测序技术测试了微生物群落,分析了微生物群落结构特征.研究结果表明,芜湖市三条城市内河河段细菌多样性丰富,主要菌门种类相似,包括变形菌门(Proteobacteria)、放线菌门(Actinobacteria)蓝细菌门(Cyanobacteria)和拟杆菌门(Bacteroidetes),其中汇成河段水中的蓝细菌门(Cyanobacteria)、Chao1指数和Shannon指数最高,蓝细菌门(Cyanobacteria)从上游到下游显著增加,污水管网老化泄漏及点源排放是导致该河段Chao1指数和Shannon指数偏高的主要原因.冗余分析(RDA)表明总氮(TN)在三条城市内河河段的水生细菌群落分布中起关键作用,氨氮(NH_(3)-N)和总磷(TP)以及叶绿素a(Chla)也在不同程度上影响着水体中细菌群落的组成.研究结果为精准高效保障城市内河水质提供了参考.

To explore planktonic bacteria community structure characteristics and driving factors of Wuhu city inland waters,three representative cities inland river(the central city in the river,the city river,south road section)were selected as the research objects.A total of 18 monitoring cross sections were setup according to the channel length and distribution of outlet.In this study,we analyzed the community structure characteristics of planktonic bacteria in three Wuhu inland rivers by16 S rRNA high-throughput sequencing technologies,in September 2020.The results showed that Wuhu inland river had a highly abundant bacterial diversity.The main dominant bacteria species are similar,including Proteobacteria,Actinobacteria,Cyanobacteria and Bacteroidetes.Compared with the Zhongyangcheng reach and Zhongshan South Road reach,the number of Cyanobacteria in the confluence reach is significantly higher,and the number of Cyanobacteria in the confluence reach is significantly increased from upstream to downstream.The Chao1 index and Shannon index of water samples from the city river system are obviously higher than those from the Central City River system and the South Zhongshan Road River.This consequence may be resulted from peripheral sewage pipe network aging leakage and point source discharge.The result of redundancy analysis(RDA)showed that total nitrogen(TN)play key roles in the distribution of aquatic bacterial community in three urban inland rivers.And mmonia nitrogen(NH_(3)-N),total phosphorus(TP)and chlorophyll a(Chla)also affect the composition of bacterial community.These findings may provide a reference for efficiently governing the water quality of city inland river.