丰水期长荡湖入湖河流微生物群落结构特征及影响因素

Characteristics of microbial community structure and influencing factors in rivers entering Changdang Lake during the wet season

为探究长荡湖入湖河流微生物群落结构特征及与环境因子的响应关系,在综合考虑主要入湖河流和污染源类型等因素的基础上进行分组,分析入湖河流中溶解氧(DO)、pH、氮磷比(TN/TP)、水温(WT)、总有机碳(TOC)、总氮(TN)和总磷(TP)共7个理化因子的分布特征。基于16S rRNA高通量测序技术并结合Circos、ANOSIM和冗余分析(RDA)等方法分析微生物群落结构特征的差异以及微生物群落与理化因子的关系。结果表明:不同污染类型的长荡湖入湖河流中优势菌门、菌属种类相似,但相对丰度却有所差别。优势菌门包括变形菌门(Proteobacteria)、放线菌门(Actinobacteria)和拟杆菌门(Bacteroidetes);优势菌属包含hgcIclade、CL500-29marinegroup、Acinetobacter、Comamonadaceae-Unclassified和Hydrogenophaga。ANOSIM分析表明长荡湖入湖河流微生物群落结构特征与污染源类型相关。冗余分析(RDA)结果显示pH、TP与长荡湖入湖河流的优势菌门呈显著相关(P<0.05);DO、pH与长荡湖入湖河流的优势菌属呈显著相关(P<0.05)。入湖河流的微生物群落在门、属分类水平上具有较高多样性且与污染源类型和理化因子相关,这为长荡湖入湖河流污染防治和生态修复提供了数据支撑。

To understand the structural characteristics of microbial communities in rivers entering Changdang Lake and the response relationship with environmental factors,this study classified these communities based on the comprehensive assessment of the primary rivers flowing into Changdang Lake and the types of pollutant sources.The distribution characteristics of seven physicochemical indices were analyzed in rivers entering Changdang Lake,including dissolved oxygen(DO),pH,ratio of total nitrogen to total phosphorus(TN/TP),water temperature(WT),total organic carbon(TOC),total nitrogen(TN)and total phosphorus(TP).The differences in the structural characteristics of microbial communities and the relationship between microbial communities and physicochemical factors were analyzed based on 16S rRNA high-throughput sequencing technology with Circos,ANOSIM and redundancy analysis(RDA).The results showed that the dominant phyla and genera of microorganisms in rivers entering Changdang Lake with various pollution types were similar,though the relative abundance differed.The dominant phyla included Proteobacteria,Actinobacteria and Bacteroidetes;the dominant genera included hgcI clade,CL500-29 marine group,Acinetobacter,Comamonadaceae-Unclassified and Hydrogenophaga.ANOSIM analyses showed that the microbial community structure characteristics of rivers entering Changdang Lake were related to the type of pollution source.The results of redundancy analysis(RDA)showed that pH and TP were significantly associated with the dominant phylum of bacteria in rivers entering Changdang Lake(P<0.05);DO and pH were extremely associated with the dominant genus of bacteria in rivers entering Changdang Lake(P<0.05).The microbial communities in rivers entering the Changdang Lake were highly diverse at the phylum and genus levels and were correlated with type of pollution sources and physicochemical factors,which provided basis for the pollution prevention and ecological restoration of rivers entering the Changdang Lake.