Quorum sensing bacteria improve microbial networks stability and complexity in wastewater treatment plants

Qiuju Liu; Deyuan Dong; Ying Jin; Qian Wang; Fuzheng Zhao; Linwei Wu; Jinfeng Wang; Hongqiang Ren

doi:10.1016/j.envint.2024.108659

Quorum sensing bacteria improve microbial networks stability and complexity in wastewater treatment plants

Environ Int. 2024 Apr 24:187:108659. doi: 10.1016/j.envint.2024.108659. Online ahead of print.

Authors

Qiuju Liu¹, Deyuan Dong¹, Ying Jin¹, Qian Wang¹, Fuzheng Zhao², Linwei Wu³, Jinfeng Wang⁴, Hongqiang Ren¹

Affiliations

¹ State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, China.
² School of Environmental and Municipal Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China.
³ College of Urban and Environmental Sciences, Peking University, Peking 100871, China.
⁴ State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210023, Jiangsu, China. Electronic address: jfwang@nju.edu.cn.

PMID: 38678933
DOI: 10.1016/j.envint.2024.108659

Abstract

Quorum-sensing bacteria (QSB) are crucial factors for microbial communication, yet their ecological role in wastewater treatment plants (WWTPs) remains unclear. Here, we developed a method to identify QSB by comparing 16S rRNA gene sequences. QSB in 388 activated sludge samples collected from 130 WWTPs across China primarily were identified as rare taxa and conditionally rare taxa. A co-occurrence network shared by all sludge communities revealed that QSB exhibited higher average clustering coefficient (0.46) than non-QSB (0.15). Individual sludge networks demonstrated that quorum sensing microbiomes were positively correlated with network robustness and network complexity, including average clustering coefficient and link density. We confirmed that QSB keystones and QSB nodes have a positive impact on network complexity by influencing network modularity through a structural equation model. Meanwhile, QSB communities directly contributed to maintaining network robustness (r = 0.29, P < 0.05). Hence, QSB play an important role in promoting network complexity and stability. Furthermore, QSB communities were positively associated with the functional composition of activated sludge communities (r = 0.33, P < 0.01), especially the denitrification capacity (r = 0.45, P < 0.001). Overall, we elucidated the ecological significance of QSB and provided support for QS-based regulation of activated sludge microbial communities.

Keywords: Activated sludge; Bacterial interaction; Community stability; Microbial communication; Microbial community; Network structure.