Extracellular polymeric substancesdantibiotics interaction in activated sludge: A review

Antibiotics, the most frequently prescribed drugs, have been widely applied to prevent or cure human and veterinary diseases and have undoubtedly led to massive releases into sewer networks and wastewater treatment systems, a hotspot where the occurrence and transformation of antibiotic resis-tance take place. Extracellular polymeric substances (EPS), biopolymers secreted via microbial activity, play an important role in cell adhesion, nutrient retention, and toxicity resistance. However, the potential roles of sludge EPS related to the resistance and removal of antibiotics are still unclear. This work summarizes the composition and physicochemical characteristics of state-of-the-art microbial EPS, highlights the critical role of EPS in antibiotics removal, evaluates their defense performances under different antibiotics exposures, and analyzes the typical factors that could affect the sorption and biotransformation behavior of antibiotics. Next, interactions between microbial EPS and antibiotic resistance genes are analyzed. Future perspectives, especially the engineering application of microbial EPS for antibiotics toxicity detection and defense, are also emphatically stressed.(c) 2022 The Authors. Published by Elsevier B.V. on behalf of Chinese Society for Environmental Sciences, Harbin Institute of Technology, Chinese Research Academy of Environmental Sciences. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Automated summary

Antibiotics, widely used drugs for disease prevention and treatment, contribute to the occurrence and transformation of antibiotic resistance in sewer networks and wastewater treatment systems. This study summarizes the composition and characteristics of microbial extracellular polymeric substances (EPS), highlights their important role in antibiotics removal, evaluates their defense performance against different antibiotics, and analyzes factors affecting the sorption and biotransformation behavior of antibiotics. Furthermore, the interactions between microbial EPS and antibiotic resistance genes are examined, and the potential engineering applications of microbial EPS for antibiotics toxicity detection and defense are emphasized.