Diversity, influential factor, and communication network construction of quorum sensing bacteria in global wastewater treatment plants

Quorum sensing (QS) is widespread in the microbial world and mediates microbial relationships in communities. However, the existing knowledge is far from a full description of the complex communication-based microbial interactions in engineered ecosystems, i.e., wastewater treatment plants (WWTPs). Herein, we conducted a systematic analysis of the diversity and influential factors of the QS-related microflora through the collection of global 1186 activated sludge microbiome samples. We found that the richness of bacteria associated with the universal bacterial secondary messenger presented the highest in QS system, whereas the bacteria related to the degradation of N-Acyl-homoserine lactones occupied the main position in the quorum quenching system. The community turnover of QS microflora was found more likely to be dominated by the deterministic process, such as the dissolved oxygen and resource availability (the ratio of organic matter to microorganisms). Meanwhile, these QS microflora in turn have a profound impact on the functions of WWTPs, especially multilingual intelligencers involving various language systems, such as Nitrospira. By connecting the signal molecule synthesis and acceptance bacteria, we constructed a QS communication network, which can be a robust tool for initial investigation of signaling molecule-mediated microbial interactions. The above results were further integrated into an online access website, named Quorum Sensing Communication Network in Activated Sludge (QSCNAS) (http://www.qscnas.cn/), which allowed users to browse and capture possible QS-based interactions of target bacterium. This work contributes to the understanding of bacterial communication in WWTPs and provides a platform to help in developing potential regulation strategies.