珠江下游浮游细菌群落结构的时空分布特征

浮游细菌群落对河流变化具有高度响应性,并可能影响河流生境的生物地球化学过程.因此,了解浮游细菌群落的时空特征,阐明其在河流生态系统中的生态功能具有重要科学意义.于2016年6月和12月对珠江下游浮游细菌群落结构的时空特征进行调查研究,并采用16S rRNA高通量测序技术对样品组分进行分析.结果表明细菌群落主要由变形菌门(Proteobacteria)、放线菌门(Actinobacteria)、拟杆菌门(Bacteroidetes)、厚壁菌门(Firmicutes)、抗微菌门(Verrucomicrobia)和蓝细菌门(Cyanobacteria)组成.其中变形菌门相对丰度最高,主要包括β-变形菌纲(Betaproteobacteria)、α-变形菌纲(Alphaproteobacteria)和γ-变形菌纲(Gammaproteobacteria).季节上,丰水期Shannon-Wiener和Chao 1多样性指数高于枯水期其中芽孢杆菌纲(Bacilli)和黄杆菌纲(Flavobacteriia)差异显著;空间上,珠江下游可分为西江沿线、珠三角河网中部和广州市周边3个区域.采用RDA分析...

Spatial and temporal distribution characteristics of bacterioplankton community structure in the downstream of Pearl River

The bacterioplankton community is highly responsive to river changes and may affect the biogeochemical processes of river habitats. Consequently, understanding the temporal and spatial characteristics of bacterioplankton communities and revealing their ecological functions in river ecosystems have important scientific significance. In June and December 2016, the research team investigated the temporal and spatial characteristics of the bacterioplankton community structure in the downstream of Pearl River, and analyzed the sample components using 16S rRNA high-throughput sequencing technology. The dominant bacterial community included Proteobacteria, Actinobacteria, Bacteroidetes, Firmicutes, Verrucomicrobia and Cyanobacteria. The relative abundance of Proteobacteria was the highest, and its main components included Betaproteobacteria, Alphaproteobacteria and Gammaproteobacteria. The diversity index of Shannon-Wiener and Chao 1 in the wet season was higher than in the dry season, and the difference between Bacilli and Flavobacteriia was significant. The downstream of Pearl River can be divided into the Xijiang River, the middle of Pearl River Delta and the surrounding areas of Guangzhou. RDA analysis showed that water temperature(WT), dissolved oxygen(DO), phosphate(PO₄^3--P), silicate(SiO₄^2--Si), total phosphorus(TP) and transparency(SD)were the most significant environmental factors driving the change in bacterial community, and may have affected the increment metabolism of bacteria. Water temperature and transparency are important factors affecting seasonal differences. The differences between wet and dry seasons; DO; chemical oxygen demand(COD); and nutrients(PO₄^3--P, SiO₄^2--Si, TP)were important factors affecting spatial differences; these distinguished the mainstream of the Xijiang River, the middle of Pearl River Delta and the surrounding areas of Guangzhou. PICRUSt functional predictive analysis showed that Transporters, ABC transporters, DNA repair and recombination proteins were the main functions expressed by the bacterioplankton community in the downstream of Pearl River. The ABC transporters and Transporters were significantly higher in the wet season than in the dry season. The research results can provide a scientific reference for the ecological environment protection in the downstream of Pearl River.