Magnetic cross-linked enzyme aggregates (M-CLEAs) were prepared for Cerrena laccase and used in antibiotic treatment. Of the seven antibiotics examined in this study, Cerrena laccase M-CLEAs were most effective in degradation of tetracycline (TC) and oxytetracycline (OTC), followed by ampicillin, suliamethoxazole and erythromycin. The redox mediator ABTS was not able to improve efficiencies of degradation of TC and OTC. Cerrena laccase at 40 U/mL eliminated 100 mu g/mL TC at pH 6 and 25 degrees C in 48 h in the absence of a redox mediator, with over 80% degradation occurring within the first 12 h. Laccase treatment also significantly suppressed the antimicrobial activity of TC and OTC. Three TC transformation products, the levels of which initially increased and subsequently decreased during laccase treatment were identified by using LC-TOF MS. A mechanism of laccase-mediated TC oxidation was proposed based on the identified intermediates. (C) 2016 Elsevier B.V. All rights reserved.