Regulating community redox metabolism for systematic mitigation of antibiotic chemical and biological risks

Abstract

The evolution of antimicrobial resistance (AMR) during antibiotic biological treatment is an unavoidable focus. However, little is known about how to regulate the systematic mitigation pathways for antibiotic chemical and biological risks. Here, we explore micro-aeration coupled with electrostimulation to regulate community redox metabolism, ultimately enhancing both the biodegradation of sulfamethoxazole (SMX) and the mitigation of antibiotic resistance genes (ARGs). Compared to anaerobic conditions, this combined regulation significantly increased the biodegradation rate of SMX and its degradation products. SMX initially underwent carbon-nitrogen bond cleavage to form 4-aminobenzenesulfonamide (SA) and was subsequently degraded primarily to p-aminophenol (p-AP) via oxidase activity on the carbon-sulfur bond, with all products displaying reduced risk quotients. The combined regulation enriched gene abundances related to energy generation (e.g., oxidative phosphorylation) and electron transfer (e.g., cytochrome c oxidase and redox mediator biosynthesis). Enhanced SMX biodegradation corresponded with significant reductions in both overall and SMX-specific ARGs (e.g., sul2), and a decrease in ARG mobility and host pathogenicity. This is likely linked to reduced selective stress as evidenced by diminished anti-ROS gene enrichment. These findings provide new insights into the mechanisms underlying enhanced SMX biodegradation and offer promising regulation strategies for systematic mitigation of antibiotic chemical and biological risks.