Broad Influence of Quorum Sensing in Environmental Biotechnology: From Mechanisms to Applications

Quorum sensing (QS), a pivotal cell-to-cell communication mechanism in microbial communities, plays a significant role in regulating microbial behaviors such as biofilm formation and sludge granulation, which are critical for the efficiency of wastewater treatment systems. This review provides thorough insight into the QS pathway modulation, focusing on the utilization of signaling molecules, particularly N-acyl homoserine lactones (AHLs), to augment microbial aggregation and extracellular polymeric substance synthesis within wastewater biotreatment system. The strategic addition of exogenous AHLs has been demonstrated to significantly accelerate the granulation process in aerobic and anaerobic sludge, leading to the development of more stable and compact granules with enhanced settling velocity and nutrient removal efficiency. Furthermore, the QS pathway significantly impacts microbial community structure and function, with diverse signaling molecules forming a complex regulatory network that can be leveraged to improve the performance of biotechnological processes. In addition to enhancing the advantageous attributes of biofilms, researchers have also immersed themselves in the exploration of quorum quenching (QQ) strategies. These strategies are adeptly applied to disrupt QS pathways, thereby effectively managing membrane fouling within membrane bioreactors (MBRs). By employing QQ enzymes, synthetic analogs, and QQ bacterial strains, researchers present effective approaches to mitigate biofilm-related issues without adversely affecting the microbial treatment processes. The innovative use of immobilized QQ enzymes and the integration of QQ strains into the MBRs have shown promising results in reducing fouling and maintaining operational stability. This review highlights the dual potential of QS manipulation for both enhancing desirable microbial process and controlling detrimental ones. By providing a deeper understanding of the underlying mechanisms and practical applications for QS/QQ pathway, scholars would be expected to develop more efficient and sustainable environmental biotechnology solutions for wastewater treatment and beyond.