冬季太湖底泥细菌群落结构特征及其与环境因子的相关性

Bacterial Community Structure and Correlation with Environmental Factors in Taihu Lake Sediment in Winter

为系统了解冬季太湖底泥细菌群落结构特点及环境影响因子,在全湖范围内采集16个点位样品,测定pH值、溶解氧(DO),电导率(EC)、温度(T)等水质指标和底泥总氮(TN)、总磷(TP)、硝态氮(NO^(-)_(3)-N),氨态氮(NH^(+)_(4)-N)、亚硝酸盐氮(NO^(-)_(2)-N)等元素指标,同时采用高通量测序技术分析不同点位底泥细菌群落结构。结果表明:太湖大部分点位底泥中TP处于中度污染,竺山湖和西太湖污染较严重。研究共鉴定出隶属32个门362个属的微生物。在门水平上,变形菌门(Proteobacteria)、绿弯菌门(Chloroflexi),酸杆菌门(Acidobacteria)为优势菌群;在属水平上,最具代表性的微生物是Steroidobacter,Gp6和Gp16,且它们在TP污染严重的竺山湖和西太湖相对丰度要高于其他湖区。典型相关分析发现,TP对太湖底泥微生物群落结构及分布影响最为显著,其次是NO--N;水体指标对其影响程度为EC>T>pH值>DO。

To understand the bacterial community structure and environmental impact factors in Taihu Lake sediment on a large scale,water and sediment samples were collected from 16 sites in winter,which cover most of the lake district.The water quality including pH value,dissolved oxygen,electrical conductivity,and temperature were determined.And the total nitrogen,total phosphorus,nitrate-nitrogen,ammonium nitrogen,nitrite nitrogen in the sediment were measured.The bacterial community structure in sediment at different sites was analyzed by high-throughput sequencing.The results showed that the TP in the sediment of most sites in Taihu Lake was at a moderate pollution level,but Zhushan bay and West Taihu Lake were at a heavy pollution level.The bacterial community structures in 16 sites were different.This study identified 32 phylum and 362 genus-level microbes,with Proteobacteria,Chloramcinophylla,and Acidobacteria as the dominant flora.At the genus level,microbes with high abundance include Steroidobacter,GP6 and GP16.Their abundances were higher in Zhushan bay and West Taihu Lake which were heavily polluted by TP.The canonical correspondence analysis found that TP had the most significant influence on the microbial community structure and distribution in Taihu lake sediment,followed by NO^(-)_(3)-N.The order of influence of the water index was EC>T>pH>DO.