School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, 250101, China; Resources and Environment Innovation Institute, Shandong Jianzhu University, Jinan, 250101, China.
School of Municipal and Environmental Engineering, Shandong Jianzhu University, Jinan, 250101, China.
Environ Res. 2023 Jan 1;216(Pt 1):114419. doi: 10.1016/j.envres.2022.114419. Epub 2022 Sep 27.
Nitrifying system is an effective strategy to remove numerous antibiotics, however, the contribution of ammonia-oxidizing bacteria (AOB), ammonia-oxidizing archaea (AOA) and heterotrophs for antibiotic removal are still unclear. In this study, the mechanism of β-lactam antibiotic (cefalexin, CFX) removal was studied in a nitrifying sludge system. Results showed that CFX was synergistically removed by AOB (Nitrosomonas, played a major role) and AOA (Candidatus_Nitrososphaera) through ammonia monooxygenase-mediated co-metabolism, and by heterotrophs (Pseudofulvimonas, Hydrogenophaga, RB41, Thauera, UTCFX1, Plasticicumulans, Phaeodactylibacter) through antibiotic resistance genes (ARGs)-encoded β-lactamases-mediated hydrolysis. Regardless of increased archaeal and heterotrophic CFX removal with the upregulation of amoA in AOA and ARGs, the system exhibited poorer CFX removal performance at 10 mg/L, mainly due to the inhibition of AOB. This study provides new reference for the important roles of heterotrophs and ARGs, opening the possibilities for the application of ARGs in antibiotic biodegradation.
硝化系统是去除多种抗生素的有效策略，然而，氨氧化细菌（AOB）、氨氧化古菌（AOA）和异养菌对抗生素去除的贡献仍不清楚。本研究在硝化污泥系统中研究了β-内酰胺抗生素（头孢氨苄，CFX）的去除机制。结果表明，CFX 协同通过氨单加氧酶介导的共代谢被 AOB（主要起作用的硝化单胞菌）和 AOA（Candidatus_Nitrososphaera）去除，通过异养菌（假诺卡氏菌、氢噬菌属、RB41、陶厄氏菌、UTCFX1、塑料杆菌、黄杆菌）通过抗生素抗性基因（ARGs）编码的β-内酰胺酶介导的水解去除。尽管通过 AOA 中 amoA 的上调和 ARGs 的增加增加了古菌和异养菌的 CFX 去除，但在 10mg/L 时系统表现出较差的 CFX 去除性能，主要是由于 AOB 的抑制。本研究为异养菌和 ARGs 的重要作用提供了新的参考，为 ARGs 在抗生素生物降解中的应用开辟了可能性。
