太湖竺山湾春季浮游细菌群落结构及影响因素

为研究太湖竺山湾春季浮游细菌群落结构,利用高通量测序对竺山湾4个采样点(雅浦港、沙塘港、竺山湖南和椒山)浮游细菌的16S rRNA基因进行序列测定.结果表明:测序文库的覆盖率很高,测序结果完全可以代表样本的真实情况;椒山的物种丰富度最高,但物种分布均匀度较低;竺山湾主要优势菌门为蓝藻门(Cyanobacteria)、放线菌门(Actinobacteria)、变形菌门(Proteobacteria)和拟杆菌门(Bacteroidetes),蓝藻门平均丰度高达64.73%,正处于水体复苏阶段,已有蓝藻水华暴发态势.属水平优势细菌主要有鱼腥藻属(Anabaena)、hgc I_clade、CL500-29_marine_group、微囊藻属(Microcystis)、聚球藻属(Synechococcus)和分枝杆菌属(Mycobacterium);运用冗余分析(RDA)探讨浮游细菌与环境因子的关系,结果表明,水温、Chl-a、NH+4-N、DO和PO3-4-P是影响浮游细菌群落的主要环境因子,其中,DO能显著影响微囊藻属,营养盐和水温对其也有一定程度影响.

Community Structure and Influencing Factors of Bacterioplankton in Spring in Zhushan Bay, Lake Taihu

In order to investigate the characteristics of bacterioplankton in the spring in Zhushan Bay, Lake Taihu, the 16S rRNA gene of the bacterioplankton at four sampling sites in Zhushan Bay was sequenced by high-throughput sequencing using water samples collected from Yapugang, Shatanggang, Zhushanhunan, and Jiaoshan. The results showed that the coverage of the sequencing library was very high and could accurately represent the bacterioplankton community in the samples. The species richness of Jiaoshan was the highest, but the species evenness was lower. Cyanobacteria, Actinobacteria, Proteobacteria, and Bacteroidetes were the dominant phylum in Zhushan Bay. The average abundance of Cyanobacteria was as high as 64.73%, which indicated an outbreak of cyanobacteria bloom in the water. At the genus level, Anabaena, hgcI_clade, CL 500-29 _marine_group, Microcystis, Synechococcus, and Mycobacterium were predominant. The results of redundancy analysis (RDA) for the relationship between bacterioplankton and environmental factors showed that water temperature, chlorophyll a (Chl-a), ammonia nitrogen(NH₄⁺-N), dissolved oxygen (DO), and phosphate (PO₄^3--P)were the main environmental factors affecting the bacterioplankton community. Dissolved oxygen could significantly affect Microcystis; nutrient and water temperature also had an effect.