Enhanced removal of tetracycline and doxycycline in aquaculture pond sediments via synthetic bacterial consortium: Efficacy and ecological risk assessment.

Tetracycline antibiotics (TCs), extensively used in aquaculture and livestock production, pose significant ecological risks due to their accumulation in aquatic sediments. This study investigated the efficacy and ecological implications of bioaugmentation with a synthetic microbial consortium for the remediation of TCs-contaminated aquaculture pond sediment. Sediment microcosms were amended with tetracycline (TC) and doxycycline (DOX) at different dosages, with or without consortium inoculation. Bioaugmentation markedly enhanced antibiotic removal, achieving complete degradation within 5-12 days, depending on the dosage. However, both high antibiotic exposure and exogenous microbial introduction lowered microbial alpha diversity. The inoculated strains, Sphingobacterium and Chryseobacterium, were selectively enriched in bioaugmented treatments, indicating a strong adaptability to elevated antibiotic pressure. Notably, bioaugmentation markedly decreased the relative abundance of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs), as well as the number of ARG-hosting taxa. These findings underscored the potential of bioaugmentation as an effective and environmentally compatible strategy for mitigating antibiotic pollution and limiting ARG dissemination in sediment environments.