A reusable and leakage-proof immobilized laccase@UiO-66-NH2(30) for the efficient biodegradation of rifampicin and lincomycin

Abstract

The enzyme leakage in physical adsorption dramatically limits the application of immobilized laccase (Lac) in environmental treatment. Therefore, a leakage-proof Zr-based metal-organic framework (MOF) carrier, UiO-66-NH2(30), was constructed for the stable loading of Lac and efficient antibiotic biodegradation, which could fix the Lac inside the carrier rather than only adsorbed on the surface. Based on the aperture modulation strategy, the pore size distribution of MOFs at about 10 nm was significantly increased to match the diameter of Lac (7.6 nm), by which Lac@UiO-66-NH2(30) was successfully prepared with a high enzyme loading amount (275.96 mg/g) and high enzyme recovery (618 %). The immobilized Lac@UiO-66-NH2(30) could nearly 100 % biodegrade rifampicin and lincomycin in 6 min and 6 h, respectively, and after 8 times reuse, the degradation rates of antibiotics remained at 81.46 % and 76.12 %, which showed excellent reusability and stability. Overall, Lac@UiO-66-NH2(30) is expected to be an ideal candidate for pollution control.