浅水湖泊底泥细菌群落的时空分布特征及主要营养盐驱动因素

Spatial-temporal Distribution of Bacterial Communities and Main Nutrients Driver of Sediment in A Shallow Lake

为探究富营养化浅水湖泊底泥中细菌群落的结构特征及驱动因素,本研究以安徽八里河湖为例,通过16S rRNA高通量测序手段并结合底泥的营养盐理化性质,分析了底泥细菌群落物种组成和多样性的时空分布特征以及与营养盐的相关性关系。结果显示:(1)在物种组成方面,γ-变形菌纲(Gammaproteobacteria),δ-变形菌纲(Deltaproteobacteria)和拟杆菌纲(Bacteroidia)是八里河湖底泥中的优势菌纲,它们在空间上呈均质性和在季节上有稳定性;(2)在群落结构方面,底泥细菌群落整体上以季节进行聚类,呈现了季节内的相似性和季节间的差异性,且可能来自于鱼类粪便的Clostridia菌纲在八里河湖底泥细菌群落结构差异的塑造上有重要贡献;(3)从四个季节所有样品的整体角度来看,与磷相关的指标(总磷、铁铝结合态磷、钙磷、有机磷)对细菌群落变化的解释最强(r=0.23~0.45,p<0.001),且底泥细菌群落之间的差异性随各磷指标内部之间差异的增大而增大。本研究的发现为认识和理解富营养化浅水湖泊中底泥细菌群落特征及其驱动因素提供了新的信息,对湖泊生态系统健康状态的监测和评估有重要意义。

To explore the eutrophication of shallow water in the lake sediment bacteria community structure characteristics and driving factors,the sediment bacterial community from a eutrophic shallow lake-Lake Balihe-located in Anhui Province,China,was investigated by using 16S rRNA high-throughput sequencing method combined with the analysis of sediment nutrients,spatially and seasonally.The results indicated that:(1)In terms of species composition,-Gammaproteobacteria,-Deltaproteobacteria and Bacterodia were the dominant bacteria in sediment,and homogeneous in space and stable in season;(2)For community structure,the sediment bacterial communities were clustered by season as a whole,which showed the intra-seasonal similarity and inter-seasonal difference.The Clostridia derived from fish feces,could be an important contribution to the shaping of bacterial community structure in sediment;(3)From the overall perspective of all samples in four seasons,phosphorus-related factors(total phosphorus,NaOH extractable phosphorus,HCl extractable phosphorus,and organic phosphorus)had significant correlation for bacterial community variations(p<0.001).The dissimilarity between bacterial communities increased with the increasing dissimilarity within each of these factors.The results from this study provide new information for understanding the traits of sediment bacterial communities and their nutrient driving factors in eutrophic shallow lakes which is meaningful for monitoring and evaluating the health status of lake ecosystems.