摘要
      硝化系统是去除多种抗生素的有效策略，但氨氧化菌（AOB）、氨氧化古菌（AOA）和异养菌对抗生素去除的贡献尚不清楚。本研究在硝化污泥系统中研究了β-内酰胺类抗生素（头孢氨苄，CFX）的去除机理。结果表明，通过氨单加氧酶介导的共代谢，AOB（硝化单胞菌，起主要作用）和AOA（Candidatus_Nitrosphaera）协同去除CFX，并通过抗生素抗性基因（ARGs）编码的β-内酰胺酶介导水解，异养菌（假富维单胞菌、Hydrogenophaga、RB41、Thauera、UTCFX1、Plasticicumans、Phaeodactylibacter）协同去除。无论AOA和ARGs中amoA的上调增加了古菌和异养CFX的去除，该系统在10mg/L时表现出较差的CFX去除性能，这主要是由于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。
Abstract
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.

https://www.sciencedirect.com/science/article/abs/pii/S0013935122017467