Marine bacterial community plays a vital role in the formation of the hypoxia zone in coastal oceans.Yet,their dynamics in the seasonal hypoxia zone of the Bohai Sea (BHS) are barely studied.Here,the 16S rRNA gene-based high-throughput sequencing was used to explore the dynamics of their diversity,structure,and function as well as driving factors during the gradual deoxygenation process in the BHS.Our results evinced that the bacterial community was dominated by Proteobacteria,followed by Bacteroidetes,Firmicutes,Actinobacteria,and Cyanobacteria,etc.The abundant subcommunity dominated in the number of sequences(49％) while the rare subcommunity dominated in the number of species (99.61％).Although abundant subcommunity accounted for most sequences,rare subcommunity possessed higher diversity,richness and their population dramatically changed (higher turnover) dur-ing the hypoxia transition.Further,co-occurrence network analysis proved the vital role of rare subcommunity in the process of community assembly.Additionally,beta diversity partition revealed that both subcommunities possessed a higher turnover component than nestedness and/or richness component,implying species replacement could explain a con-siderable percentage of community variation..This variation might be governed by both en-vironmental selection and stochastic processes,and further,it influenced the nitrogen cycle(PICRUSt-based prediction) of the hypoxia zone.Overall,this study provides insight into the spatial-temporal heterogeneity of bacterial and their vital role in biogeochemical cycles in the hypoxia zone of the BHS.These findings will extend our horizons about the stabiliza-tion mechanism,feedback regulation,and interactive model inside the bacterial community under oxygen-depleted ecosystems.

Chao Wu;Jinjun Kan;Dhiraj Dhondiram Narale;Kun Liu;Jun Sun

Tianjin Key Laboratory of Marine Resources and Chemistry,Tianjin University of Science and Technology,Tianjin 300457,China;Research Centre for Indian Ocean Ecosystem,Tianjin University of Science and Technology,Tianjin 300457,China;Department of Microbiology,Stroud Water Research Center,Avondale,PA 19311,USA;Laboratory of Marine Biology and Ecology,Third Institute of Oceanography,Ministry of Natural Resources,Xiamen 361005,China;College of Marine Science and Technology,China University of Geosciences (Wuhan),Wuhan 430074,China

环境科学学报（英文版）

[1]Chao Wu;Jinjun Kan;Dhiraj Dhondiram Narale;Kun Liu;Jun Sun-.Dynamics of bacterial communities during a seasonal hypoxia at the Bohai Sea:Coupling and response between abundant and rare populations)[J].环境科学学报（英文版）,2022(01):324-339

evinced,subcommunity,subcommunities,stabiliza

Dynamics,bacterial,during,seasonal,hypoxia,Bohai,Sea,Coupling,response,between,abundant,rare,populations,Marine,plays,vital,role,formation,zone,coastal,oceans,Yet,their,dynamics,BHS,barely,studied,Here,16S,rRNA,throughput,sequencing,was,used,explore,diversity,structure,function,well,driving,factors,gradual,deoxygenation,Our,results,that,dominated,by,Proteobacteria,followed,Bacteroidetes,Firmicutes,Actinobacteria,Cyanobacteria,etc,number,sequences,while,species,Although,accounted,most,possessed,higher,richness,dramatically,changed,turnover,transition,Further,occurrence,network,analysis,proved,assembly,Additionally,beta,partition,revealed,both,component,than,nestedness,implying,replacement,could,explain,con,siderable,percentage,variation,This,might,governed,vironmental,selection,stochastic,processes,further,influenced,nitrogen,PICRUSt,prediction,Overall,this,study,provides,insight,into,spatial,temporal,heterogeneity,biogeochemical,cycles,These,findings,will,extend,our,horizons,about,mechanism,feedback,regulation,interactive,model,inside,under,depleted,ecosystems

0.536077