Wang Bingzheng, Wang Yaqin, Fang Jiali, Feng Ziheng, Hu Haoxing, Zhong Huiyun, Chen Sisi, Li Ji
Jiangsu Key Laboratory of Anaerobic Biotechnology, School of Environment and Ecology, Jiangnan University, Wuxi, 214122, China.
School of Urban Construction, Changzhou University, Changzhou, 213164, China.
Environ Pollut. 2025 Jan 1;364(Pt 2):125396. doi: 10.1016/j.envpol.2024.125396. Epub 2024 Nov 23.
The removal of antibiotics in wastewater treatment plants (WWTPs) is generally insufficient. Studies have proved that ammonia-oxidizing bacteria (AOB) are capable of degrading antibiotics through cometabolism. However, the actual operating conditions in WWTPs are generally unfavorable for AOB to fully reach its cometabolic potential. Studies have demonstrated that exogenous N-acyl homoserine lactones (AHLs) can enhance the treatment efficiency of wastewater treatment microorganisms by regulating their quorum sensing system. However, few studies have reported the effect of exogenous AHLs on the cometabolic removal of antibiotics by AOB. In this study, a typical AHL, N-hexanoyl-L-homoserine lactone (C6-HSL), was selected to explore its effects on the cometabolic removal of a typical antibiotic, sulfadiazine (SDZ), by an enriched AOB culture and the microbial responses of the culture during the process. The results showed that the exposure to SDZ (0.1-10 mg/L) led to the decrease in ammonia oxidation rate, the concentrations of intracellular adenosine triphosphate and ammonia oxygenase (AMO) and the abundances of amoA gene and AOB, while more extracellular polymeric substances (EPS) were secreted to resist the adverse effects brought by SDZ. With the simultaneous addition of SDZ (1 and 10 mg/L) and exogenous C6-HSL (1 μM), it was found that C6-HSL significantly enhanced the removal efficiency and rate of SDZ by the enriched AOB culture. By promoting EPS secretion, strengthening energy metabolism, promoting AMO synthesis, increasing AOB and amoA gene abundances and altering microbial community structure, C6-HSL restored the microbial activity and alleviated the pressure on microorganisms induced by SDZ. It is expected that this study could provide a new strategy for enhancing antibiotics removal in wastewater.
污水处理厂（WWTPs）中抗生素的去除通常并不充分。研究表明，氨氧化细菌（AOB）能够通过共代谢作用降解抗生素。然而，污水处理厂的实际运行条件通常不利于AOB充分发挥其共代谢潜力。研究表明，外源性N-酰基高丝氨酸内酯（AHLs）可以通过调节其群体感应系统来提高废水处理微生物的处理效率。然而，很少有研究报道外源性AHLs对AOB共代谢去除抗生素的影响。在本研究中，选择了一种典型的AHL，N-己酰基-L-高丝氨酸内酯（C6-HSL），以探讨其对富集的AOB培养物共代谢去除典型抗生素磺胺嘧啶（SDZ）的影响以及该过程中培养物的微生物响应。结果表明，暴露于SDZ（0.1-10mg/L）会导致氨氧化速率、细胞内三磷酸腺苷和氨单加氧酶（AMO）浓度以及amoA基因和AOB丰度降低，同时会分泌更多的胞外聚合物（EPS）来抵抗SDZ带来的不利影响。在同时添加SDZ（1和10mg/L）和外源性C6-HSL（1μM）的情况下，发现C6-HSL显著提高了富集的AOB培养物对SDZ的去除效率和速率。通过促进EPS分泌、加强能量代谢、促进AMO合成、增加AOB和amoA基因丰度以及改变微生物群落结构，C6-HSL恢复了微生物活性并减轻了SDZ对微生物的压力。预计本研究可为提高废水中抗生素的去除提供一种新策略。
