丹江口水库是南水北调工程的重要水源,拥有不同深度的浮游细菌群落,对其氮磷循环和相关驱动因素的理解仍然有限。在这项研究中,我们选取丹江口水库内的5个生态点进行宏基因组学分析,研究浮游细菌群落在地表的垂直分布,中间,和底层。此外,我们分析和预测了氮和磷循环的功能,以及他们的驱动因素。我们的发现揭示了变形杆菌的优势,放线菌,和丹江口水库的植物。在不同深度的浮游细菌群落结构中观察到显著差异,随着温度(T),氧化还原电位(ORP),溶解氧(DO),Chla被确定为影响浮游细菌组成的主要因素。氮循环功能基因的分析鉴定出39个基因,包括gltB,glnA,gltd,gdha,NRT,等。,涉及七个主要途径,包括固氮,硝化,反硝化,和异化硝酸盐还原。磷循环功能基因分析确定了54个基因,包括pstS,ppx-gppA,glpQ,ppk1等。,主要参与六个主要途径,包括有机磷矿化,无机P增溶,和监管。聚类分析表明,不同深度是影响氮磷循环功能基因组成和丰度的显著因素。表层和底层氮磷循环功能基因的组成和丰度不同,并且普遍高于中间层。异常球菌,Hydrogenophaga,Limnohabitans,Clavibacter,其他物种被确定为参与氮磷循环的关键物种。此外,我们发现氮磷循环功能基因与环境因子如DO,pH值,T,总溶解固体(TDS),电导率(EC),还有Chla.此外,这些环境因素的含量在丹江口水库中表现出与深度相关的变化,导致浮游细菌氮和磷循环功能基因的垂直分布模式。总的来说,这项研究揭示了成分,函数,丹江口水库不同层浮游细菌群落及其影响因素,为这个重要的水库生态系统中浮游细菌的生态功能和多样性保护提供了有价值的见解。
Danjiangkou Reservoir is a critical water source for the South-to-North Water Diversion Project, which harbors a diverse bacterioplankton community with varying depths, and the understanding of its nitrogen and phosphorus cycle and associated driving factors remains limited. In this study, we selected five ecological sites within Danjiangkou Reservoir and conducted metagenomics analysis to investigate the vertical distribution of bacterioplankton communities in the surface, middle, and bottom layers. Furthermore, we analyzed and predicted the function of nitrogen and phosphorus cycles, along with their driving factors. Our findings revealed the dominance of Proteobacteria, Actinobacteria, and Planctomycetes in the Danjiangkou Reservoir. Significant differences were observed in the structure of bacterioplankton communities across different depths, with temperature (T), oxidation-reduction potential (ORP), dissolved oxygen (DO), and Chla identified as primary factors influencing the bacterioplankton composition. Analysis of nitrogen cycle functional genes identified 39 genes, including gltB, glnA, gltD, gdhA, NRT, etc., which were involved in seven main pathways, encompassing nitrogen fixation, nitrification, denitrification, and dissimilatory nitrate reduction. Phosphorus cycle function gene analysis identified 54 genes, including pstS, ppx-gppA, glpQ, ppk1, etc., primarily participating in six main pathways, including organic P mineralization, inorganic P solubilization, and regulatory. Cluster analysis indicated that different depths were significant factors influencing the composition and abundance of nitrogen and phosphorus cycle functional genes. The composition and abundance of nitrogen and phosphorus cycle functional genes in the surface and bottom layers differed and were generally higher than those in the middle layer. Deinococcus, Hydrogenophaga, Limnohabitans, Clavibacter, and others were identified as key species involved in the nitrogen and phosphorus cycle. Additionally, we found significant correlations between nitrogen and phosphorus cycle functional genes and environmental factors such as DO, pH, T, total dissolved solids (TDS), electrical conductivity (EC), and Chla. Furthermore, the content of these environmental factors exhibited depth-related changes in the Danjiangkou Reservoir, resulting in a distinct vertical distribution pattern of bacterioplankton nitrogen and phosphorus cycle functional genes. Overall, this study sheds light on the composition, function, and influencing factors of bacterioplankton communities across different layers of Danjiangkou Reservoir, offering valuable insights for the ecological function and diversity protection of bacterioplankton in this crucial reservoir ecosystem.