典型高原湖滨带底泥细菌群落结构及多样性特征

Bacterial community structure and diversity of sediments in a typical plateau lakeshore

摘要:

【背景】高原湖泊的富营养化日趋严重，而湖滨带作为湖泊的保护屏障对外源污染物具有拦截净化等作用，水环境变化则会对底泥细菌产生深刻影响。【目的】探究高原湖滨带底泥细菌群落结构特征及与水体富营养化之间的联系。【方法】基于16S rRNA基因高通量测序技术分析了阳宗海南岸湖滨带8个不同样点的底泥细菌群落结构及多样性，并结合样品水体环境因子，采用主成分分析(PCA)和冗余分析(redundancy analysis，RDA)，探讨了水体富营养化对底泥细菌群落结构及丰富度的影响。【结果】湖滨带底泥细菌与水体富营养化程度存在响应关系，在水体富营养化程度高的区域(S3)，细菌丰富度较高，操作分类单元(operational taxonomic units，OTU)高达1 473。反之，在富营养化程度低的区域(S1)，细菌丰富度较低，OTU为730。阳宗海南岸湖滨带底泥中主要优势菌门为变形菌门(Proteobacteria)和绿弯菌门(Chloroflexi)，含有少量的放线菌门(Actinobacteria)、酸杆菌门(Acidobacteria)和厚壁菌门(Firmicutes)；绿弯菌门(Chloroflexi)与水体富营养化程度具有相关性，在中度富营养化区域，绿弯菌门(Chloroflexi)的比重高达44.1%，而在轻度富营养化区域绿弯菌门(Chloroflexi)的比重仅为15.6%。通过环境因子分析发现，阳宗海湖滨底泥细菌受总磷(TP)、叶绿素a (chla)和总氮(TN)影响较强。【结论】研究结果明确了高原湖泊湖滨带底泥细菌种群的结构、变化特征及其对于水体富营养化的响应，加深了高原湖泊底泥细菌的了解，为高原湖泊水体富营养化的防治提供理论基础。

Abstract:

[Background] Eutrophication of plateau lakes is becoming increasingly serious. Lakeshore zone is the protective barrier for the lake and has effects on intercepting and purifying the external pollutants. Changes of water environment affect the sediment bacteria. [Objective] The aim of the present work was to explore the relationship between lakeshore sediment bacterial community structural characteristics and water bodies eutrophication. [Methods] Bacterial community structure and the diversity of eight sediments in the south bank of Yangzonghai Lake was analyzed by 16S rRNA gene high-throughput sequencing technology. Principal component analysis and redundant analysis were analyzed by comparing the differences in environmental factors of different waters, and the effects of eutrophic water on bacterial community structure and abundance in sediments. [Results] Lakeshore sediments had a certain response to water eutrophication. In high eutrophication areas (S3), the bacterial richness was high with a high OTU at 1 473. Conversely, in areas with low levels of eutrophication (S1), the bacterial richness was low and the OTU was 730. The dominant bacteria in Yangzonghai Lake lakeshore were Proteobacteria and Chloroflexi with a small group of Actinobacteria, Actidobacteria and Firmicutes. Chloroflexi was closely related to eutrophication degree in water. In moderately eutrophic areas, the proportion of Chloroflexi was as high as 44.1%, while in the light eutrophication area Chloroflexi was only 15.6%. Basing on environmental factor analysis, it was found that the bacterial community of Yangzonghai Lakeshore sediment was strongly affected by total phosphorus, chlorophyll a and total nitrogen. [Conclusion] The results clarified the structure and variation characteristics of bacterial populations in plateau lakes lakeshore and their responses to water eutrophication, helps to better the understanding of sediment bacteria in plateau lakes and provide a theoretical basis for prevention and control eutrophication in plateau lakes.