A nature-based duckweed-bacteria-fungi consortium enables comprehensive sulfamethoxazole degradation and detoxification in synthetic wastewater

Antibiotic residues in wastewater pose ecological and health risks, demanding efficient and sustainable removal strategies. A nature-based tripartite system was developed combining Spirodela polyrhiza, a sulfamethoxazole (SMX)-degrading bacterium (Pseudomonas sp. N6), and the white-rot fungus Trametes versicolor N105 for SMX removal. In sterile batch reactors (1 mg/L SMX), the consortium reduced SMX below the quantification limit (0.05 mg/L) within 12 days, outperforming duckweed alone and duckweed with a single microbial partner. Mass balance analysis showed that biodegradation (0.90 mg/L) dominated SMX dissipation, with fungal oxidative cleavage complementing bacterial hydroxylation and duckweed-mediated deamination. Physiological assays indicated that microbial partners, particularly the fungal component, alleviated SMX-induced oxidative stress and enhanced pigment synthesis, thereby improving duckweed growth. These results demonstrate that integrating duckweed, bacteria, and fungi yields enhanced SMX removal and mitigates phytotoxicity, highlighting a promising nature-based strategy for antibiotic-contaminated wastewater.