典型热带近海河流微生物群落结构特征及其碳氮磷循环特征与机制  

Structural characteristics of microbial communities in typical tropical offshore rivers and their carbon,nitrogen,and phosphorus cycling characteristics and mechanisms

作　　者：吴喆 余春瑰 刘美璇 李翀 段高旗 彭剑峰 李艳红[1] WU Zhe;YU Chungui;LIU Meixuan;LI Chong;DUAN Gaoqi;PENG Jianfeng;LI Yanhong(School of Environmental Science and Engineering,Guilin University of Technology,Guilin 541004;Center for Water and Ecology,School of Environment,Tsinghua University,Beijing 100084;Yangtze River Eco-environmental Engineering Research Center,China Three Gorges Corporation,Beijing 100038)

机构地区：[1]桂林理工大学环境科学与工程学院,桂林541004 [2]清华大学环境学院,清华大学水质与水生态研究中心,北京100084 [3]中国长江三峡集团有限公司长江生态环境工程研究中心,北京100038

出　　处：《环境科学学报》2025年第1期201-215,共15页Acta Scientiae Circumstantiae

基　　金：国家重点研发计划(No.2021YFC3200700);中国长江三峡集团有限公司项目(No.202003140)。

摘　　要：近海河流是研究陆地和海洋的物理、化学、生物、地质过程及其相互作用,以及全球环境变化与人类活动影响的重要载体.本研究以典型热带近海河流三亚西河为研究对象,采用eDNA宏条形码和qPCR功能基因芯片技术,对典型热带近海河流三亚西河上、中、下游共13个样点表层水体中浮游细菌群落多样性、结构组成、相互作用关系和组装过程以及碳(C)、氮(N)、磷(P)、硫(S)循环中71个相关功能基因丰度进行了特征分析和调控机制研究.结果表明:三亚西河的浮游细菌群落多样性、结构组成、相互作用关系和组装过程在不同河段均存在显著差异.下游入海口地区浮游细菌群落多样性降低,不同河段间的环境异质性增强,群落结构差异显著.在淡咸水交汇的中游,环境异质性增强,浮游细菌群落共现网络更为复杂,确定性过程在其群落扩散中占据主导地位.此外,对浮游细菌的功能分析表明,多数微生物介导的C、N、P循环相关功能基因的表达在下游受到抑制.随机森林分析表明,Verrucomicrobia和Tenericutes可能是参与C、N、P循环中最重要的功能菌门.冗余分析(RDA)、层次分割(HP)及Mantel检验表明,咸潮上溯导致的盐度差异是调控浮游细菌群落和C、N、P循环功能的重要机制之一.研究结果有利于加强对近海河流浮游细菌群落组成特征的认识,明晰其参与的河流和海洋生物地球化学循环过程,为监督、评估和改善水质、水环境和水生态健康与安全提供理论基础.Estuarine rivers played a crucial role in studying the physical,chemical,biological,and geological processes between land and sea,as well as their interactions,global environmental changes,and the impacts of human activities.This study focused on the West River in Sanya City,a typical tropical estuarine river.The eDNA metabarcoding and qPCR functional gene array technologies were applied to analyze the diversity,structural composition,interaction relationships,and assembly processes of planktonic bacterial communities,as well as the abundance of 71 genes related to(C)carbon,(N)nitrogen,(P)phosphorus,and(S)sulfur cycling across 13 surface water sampling sites in the upper,middle,and lower reaches of the river.Our results revealed significant differences in bacterial community diversity,structure,interaction relationships,and assembly processes among different river sections.Bacterial diversity decreased in the lower estuarine region,with increased environmental heterogeneity and distinct community structures between river segments.Environmental heterogeneity was heightened in the middle reach,where freshwater and saltwater mix,leading to a more complex microbial co-occurrence network,with deterministic processes dominating community dispersal.Furthermore,functional analysis of the planktonic bacteria indicated that the expression of most microbially mediated genes involved in C,N,and P cycling was suppressed in the downstream areas.Random Forest analysis suggested that Verrucomicrobia and Tenericutes might be the most important functional groups involved in C,N,and P cycling.Redundancy Analysis(RDA),Hierarchical Partitioning(HP),and Mantel tests indicated that salinity gradients caused by saltwater intrusion are one of the key mechanisms regulating the planktonic bacterial community and the biogeochemical cycling of C,N,and P.These findings enhanced our understanding of the compositional characteristics of estuarine river bacterial communities and clarified their role in riverine and marine biogeochemical cycles.T

关 键 词：浮游细菌 三亚西河 生物地球化学循环 功能基因 淡水盐碱化 

分 类 号：X171[环境科学与工程—环境科学] X172