Metal-organic framework-hybridized immobilized laccase for the efficient degradation of industrial wastewater pollutants

Natural laccases from Lentinula edodes exhibit remarkable catalytic versatility in degrading various organic pollutants in industrial wastewater. However, their practical applications are limited by their inherent structural instability and poor reusability. To address these limitations, we designed a robust hybrid biocatalyst, Lac@UiO-66-NH₂, through optimized immobilization strategies. Optimal conditions for achieving an immobilization efficiency of 90.16 % were as follows: enzyme loading of 7 mg/mL, incubation temperature of 25 °C, and incubation time of 1 h. The immobilized laccase exhibited significantly enhanced stability and reusability, along with remarkable biocatalytic activity, achieving degradation efficiencies of 84.87 % for malachite green and 93.54 % for methylene blue in simulated wastewater. Comprehensive characterization techniques-including scanning electron microscopy, X-ray diffraction, and Brunauer-Emmett-Teller analysis-validated successful laccase immobilization and elucidated the microstructure-performance relationship, highlighting the structural advantages of the composite. This study demonstrates the potential of Lac@UiO-66-NH₂ as a novel, highly stable, and reusable hybrid biocatalyst for efficient removal of phenolic contaminants, offering a sustainable solution for wastewater treatment. The findings underscore its practical applicability in environmental remediation and its alignment with green chemistry principles.