Spatial distribution and assembly processes of bacterial communities in riverine and coastal ecosystems of a rapidly urbanizing megacity in China

Hebin Liang; Jin Huang; Yu Xia; Ying Yang; Yang Yu; Kai Zhou; Lin Lin; Xiaoyan Li; Bing Li

doi:10.1016/j.scitotenv.2024.173298

Spatial distribution and assembly processes of bacterial communities in riverine and coastal ecosystems of a rapidly urbanizing megacity in China

Sci Total Environ. 2024 May 16:934:173298. doi: 10.1016/j.scitotenv.2024.173298. Online ahead of print.

Authors

Hebin Liang¹, Jin Huang¹, Yu Xia², Ying Yang³, Yang Yu⁴, Kai Zhou⁵, Lin Lin¹, Xiaoyan Li¹, Bing Li⁶

Affiliations

¹ State Environmental Protection Key Laboratory of Microorganism Application and Risk Control, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China.
² School of Environmental Science and Engineering, College of Engineering, Southern University of Science and Technology, Shenzhen 518055, China.
³ School of Marine Sciences, Sun Yat-Sen University, Zhuhai 519082, China; Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai 519000, China.
⁴ National Risk Assessment Laboratory for Antimicrobial Resistance of Animal Original Bacteria, South China Agricultural University, Guangzhou 510642, China; Guangdong Provincial Key Laboratory of Veterinary Pharmaceutics Development and Safety Evaluation, South China Agricultural University, Guangzhou 510642, China.
⁵ Shenzhen Institute of Respiratory Disease, Shenzhen People's Hospital (the First Affiliated Hospital, Southern University of Science and Technology; the Second Clinical Medical College, Jinan University), Shenzhen 518020, China.
⁶ State Environmental Protection Key Laboratory of Microorganism Application and Risk Control, Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen 518055, China. Electronic address: bingli@sz.tsinghua.edu.cn.

PMID: 38761945
DOI: 10.1016/j.scitotenv.2024.173298

Abstract

Rapid urbanization has precipitated significant anthropogenic pollution (nutrients and pathogens) in urban rivers and their receiving systems, which consequentially disrupted the compositions and assembly of bacterial community within these ecosystems. However, there remains scarce information regarding the composition and assembly of both planktonic and benthic bacterial communities as well as pathogen distribution in such environments. In this study, full-length 16S rRNA gene sequencing was conducted to investigate the bacterial community composition, interactions, and assembly processes as well as the distribution of potential pathogens along a riverine-coastal continuum in Shenzhen megacity, China. The results indicated that both riverine and coastal bacterial communities were predominantly composed of Gammaproteobacteria (24.8 ± 12.6 %), Alphaproteobacteria (16.1 ± 9.8 %), and Bacteroidota (14.3 ± 8.6 %), while sedimentary bacterial communities exhibited significantly higher diversity compared to their planktonic counterparts. Bacterial community patterns exhibited significant divergences across different habitats, and a significant distance-decay relationship of bacterial community similarity was particularly observed within the urban river ecosystem. Moreover, the urban river ecosystem displayed a more complex bacterial co-occurrence network than the coastal ecosystem, and a low ratio of negative:positive cohesion suggested the inherent instability of these networks. Homogeneous selection and dispersal limitation emerged as the predominant influences on planktonic and sedimentary bacterial communities, respectively. Pathogenic genera such as Vibrio, Bacteroides, and Acinetobacter, known for their roles in foodborne diseases or wound infection, were also identified. Collectively, these findings provided critical insights into bacterial community dynamics and their implications for ecosystem management and pathogen risk control in riverine and coastal environments impacted by rapid urbanization.

Keywords: Assembly process; Bacterial community; Full-length 16S rRNA gene sequencing; Pathogen distribution; Urbanization.