鄱阳湖入湖河口沉积物细菌群落特征

基于高通量测序技术分析了鄱阳湖入湖河口15处沉积物的细菌群落特征.结果发现鄱阳湖入湖河口细菌优势门类为Proteobacteria（32.1%），Acidobacteria（16.6%）、Chloroflexi（14.4%）、Nitrospirae（8.8%）和Actinobacteria（6.0%）.在属分类水平上相对丰度最高的是norank_Acidobacteria（8.9%）和Nitrospira（8.4%）.根据采样点沉积物细菌群落结构差异，5条主要支流入湖河口可分成赣江-饶河-信江组和抚河-修水组.赣江-饶河-信江组Acidobacteria、Nitrospirae、Gemmatimonadetes和Latescibacteria丰度显著较高；抚河-修水组Actinobacteria、Bacteroidetes、Firmicutes、Ignavibacteriae和Deltaproteobacteria丰度显著较高.鄱阳湖主航道下游沉积物细菌群落结构与其它入湖河口差异明显，具有显著较高的Chloroflexi、Aminicenantes和Firmicutes丰度.pH值和有机碳是影响鄱阳湖入湖河口沉积物门分类种群的主要环境因子，pH值是影响赣江-饶河-信江组和抚河-修水组细菌群落结构差异的主要环境因子.以上研究结果有助于从微生物的角度分析鄱阳湖入湖河口生态系统的物质和能量循环机理.

Bacterial communities in the estuarine sediment of Poyang Lake

In this study, we studied the bacterial community in 15 estuarine sediments of Poyang Lake using high throughput sequencing. The results showed that the dominant phyla were Proteobacteria (32.1%), Acidobacteria (16.6%), Chloroflexi (14.4%), Nitrospirae (8.8%) and Actinobacteria (6.0%). The dominant genera were norank_Acidobacteria (8.9%) and Nitrospira (8.4%). Based on the difference of the bacterial community structure in sampled estuarine sediments, the five main tributaries of Poyang Lake were divided into the Gan River-Rao River-Xin River group and the Fu River-Xiu River group:the former group had significantly higher abundance of Acidobacteria, Nitrospirae, Gemmatimonadetes and Latescibacteria, while the latter group had significantly higher abundance of Actinobacteria, Bacteroidetes, Firmicutes, Ignavibacteriae and Deltaproteobacteria. The bacterial community structure in sediment of the downstream channel of Poyang Lake had large difference with that in other estuarine sediments, and significantly higher abundance of Chloroflexi, Aminicenantes and Firmicutes was observed. The main environmental factors explaining the variations in phylum abundance were pH and organic carbon, and pH was the main environmental factor leading to the difference of bacterial community structures between Gan River-Rao River-Xin River group and the Fu River-Xiu River group. The above results can help to analyze the element and energy cycling in the estuarine ecosystem of Poyang Lake from the microbial perspective.