Impact of sulfamethoxazole on oxygen-reducing biocathodes

This study investigates the effects of sulfamethoxazole (SMX), a widely used antibiotic, on electrogenic oxygen-reducing biofilms in microbial fuel cells (MFCs). The goal is to elucidate how different concentrations of SMX influence the electrochemical performance, extracellular polymeric substances (EPS), microbial community structure, and gene expression related to electron transfer and energy metabolism. At low concentration (0.5 mg/L), SMX enhanced biofilm electroactivity and microbial diversity, while higher concentrations (10 and 30 mg/L) showed inhibitory effects. This work provides new insights into the microbial and molecular mechanisms of antibiotic stress on biocathodes, and offers valuable guidance for optimizing bioelectrochemical systems for wastewater treatment in the presence of emerging contaminants like antibiotics.