南昌城市湖泊浮游微生物群落构建机制及影响因素

Mechanisms of planktonic microbial community assembly and influencing factors in Nanchang urban lakes

为探明城市湖泊浮游微生物群落构建机制,分别于枯水期(2月、12月)、平水期(4月、10月)和丰水期(6月、8月)采集了江西省南昌市7个主要城市湖泊表层水样,测定了温度(WT)、溶解氧(DO)和氨态氮(NH_(4)^(+)-N)等水体理化指标,并基于高通量测序研究了浮游细菌与浮游真菌群落特征,揭示了浮游细菌与浮游真菌的群落构建机制与影响因素.结果表明:(1)浮游细菌群落与浮游真菌群落的群落结构均表现出显著的水期差异,WT、DO、NH_(4)^(+)-N、NO_(3)^(-)-N、pH及种间交互作用显著影响浮游细菌群落结构,DO、WT与pH是影响浮游真菌群落结构的显著水体理化指标.(2)浮游细菌群落主要受随机过程影响,浮游真菌群落主要受确定性过程影响.种间交互作用对浮游细菌群落构建影响显著,对浮游真菌构建的影响不显著.这些发现揭示了南昌城市湖泊中微生物群落的生态过程,并为理解城市湖泊微生物多样性提供科学依据.

To investigate the mechanisms of planktonic microbial community construction in urban lakes,surface water samples were collected from seven major city lakes in Nanchang,Jiangxi Province during the dry season(February and December),normal season(April and October)and wet season(June and August),respectively.Physicochemical indicators of water bodies such as WT,DO and NH_(4)^(+)-N were measured,and community characteristics of planktonic bacteria and planktonic fungi were studied based on high-throughput sequencing to reveal the community assembly mechanisms and influencing factors.The results showed that①Both the planktonic bacterial community and the planktonic fungal community showed significant hydroperiodic differences in community structure,with WT,DO,NH4_(+)^(+)-N,NO_(3)^(−)-N,pH and interspecific interactions significantly affecting the community structure of planktonic bacteria,and DO,WT and pH significantly affecting the community structure of planktonic fungi.②The planktonic bacterial community was mainly influenced by stochastic processes,while the planktonic fungal community was mainly influenced by deterministic processes.Interspecies interactions had significant effects on planktonic bacterial community assembly,and insignificant effects on planktonic fungal assembly.These findings reveal the ecological processes of microbial communities in Nanchang urban lakes and provide a scientific basis for understanding the microbial diversity of urban lakes.