铜增强磁性生物炭-漆酶复合材料协同去除四环素类抗生素的研究

Abstract

Tetracycline antibiotics (TCs) are widely used in human and veterinary medicines, posing serious threats to ecological safety and public health due to their environmental persistence. Here, we heterologously expressed a laccase from Pycnoporus sanguineus (HMLac) and prepared a novel composite, copper-loaded magnetic biochar-based immobilized laccase (CuMBC@HMLac) for the removal of TCs. Compared with HMLac, CuMBC@HMLac showed enhanced stability, metal ion tolerance, and reusability. Tetracycline (TC), oxytetracycline (OTC), chlortetracycline (CTC), and doxycycline (DOX) were efficiently removed in the CuMBC@HMLac/ABTS system, and the removal efficiency was 90.57%–100% within 6 h through synergistic mechanisms involving both enzymatic catalysis and carrier adsorption. Identification of the transformation products via LC-QTOF-MS revealed that hydroxylation, deamination, oxylation, decarbonylation, hydration, demethylation, and dehydroxylation were the dominant transformation pathways of TCs. Antibacterial experiments and ECOSAR toxicity prediction confirmed good environmental safety of the CuMBC@HMLac/ABTS system. Molecular docking and free radical analysis further revealed that ABTS ·+ was a crucial factor involved in TCs removal. Overall, this study provides theoretical and technical supports for the environmental control and remediation of TCs pollution.