太湖金墅港水源地蓝藻、细菌群落结构及垂直迁移规律研究

Study on Cyanobacteria,Bacteria Community and Vertical Migration in Water Source Area of Jinshugang,Taihu Lake

以太湖金墅港水源地蓝藻为研究对象,通过高通量测序技术分析水体和底泥中细菌的群落组成,同时检测常规水质理化因子,分析其对蓝藻变化的影响。结果显示,金墅港水体和底泥中细菌群落主要门组成相似,随着季节的变化水体中蓝藻群落结构的变化较大,底泥中蓝藻的群落结构变化较小;蓝藻门主要的优势科是微囊藻科(Microcystaceae)和聚球藻科(Synechococcales),蓝藻爆发期主要是微囊藻;影响蓝藻群落结构变化的主要环境因子是水温、溶解氧、总氮和总磷;金墅港全年共检测到12个属的溶藻细菌,主要为假单胞菌(Pseudomonas)和黄杆菌(Flavobaeteria),溶藻菌在细菌的占比与蓝藻相反,蓝藻水华爆发时比例较低,蓝藻水华爆发前期、末期则比例较高。此外还发现随着气温升高,底泥中蓝藻的繁殖优先于水体中蓝藻的繁殖;蓝藻爆发期,水体中蓝藻比例较高时会出现向底泥中迁移富集的现象。

This study took cyanobacteria form water source area of Jinshugang in Taihu Lake as the example,the cyanobacterial community composition in water and sediment was analyzed by high-throughput sequencing technology,and the effect of physicochemical parameters on the changes of cyanobacteria was also examined.The results showed that the composition of bacterial communities in water was similar with that in sediment,and the community structure of cyanobacteria in water changed greatly with the seasons,while the community structure of cyanobacteria in sediment changed little.The dominant families of cyanobacteria were Microcystaceae and Synechococcales,and the Microcystaceae was the largest families during the cyanobacteria bloom.Water temperature,dissolved oxygen,total nitrogen and total phosphorus were the main physicochemical factors affecting the change of cyanobacterial community structure.There were 12 genera of algae-dissolving bacteria detected in Jinshugang throughout the whole year,and the main bacteria were Pseudomonas and Flavobaeteria.The proportion of algae-dissolving bacteria was opposite to cyanobacteria bloom,the proportion of cyanobacteria in bacteria was low during cyanobacterial outbreaks and high at the beginning and ending of the outbreak.Besides,it was found that the cyanobacterial bloom in sediment took precedence over the cyanobacterial bloom in water as the air temperature increased.The phenomenon of migration and enrichment from water to sediment occurred when the proportion of cyanobacteria in water was high during the cyanobacterial bloom.