Enhancing Cellulose Hydrolysis via Cellulase Immobilization on Zeolitic Imidazolate Frameworks Using Physical Adsorption

Abstract This study investigates the immobilization of cellulase on zeolitic imidazolate frameworks (ZIFs) by physical adsoption, specifically ZIF-8-NH2 and Fe3O4@ZIF-8-NH2, to enhance enzymatic hydrolysis efficiency. The immobilization process was thoroughly analyzed, including optimization of conditions and characterization of ZIF carriers and immobilized enzymes. The impacts on the catalytic activity of cellulase under various temperatures, pH levels, and storage conditions were examined. Additionally, the reusability of the immobilized enzyme was assessed. Results showed the cellulase immobilized on Fe3O4@ZIF-8-NH2 exhibited a high loading capacity of 339.64 mg/g, surpassing previous studies. Its relative enzymatic activity was found to be 71.39 %. Additionally, this immobilized enzyme system demonstrates robust reusability, retaining 68.42 % of its initial activity even after 10 cycles. These findings underscore the potential of Fe3O4@ZIF-8-NH2 as a highly efficient platform for cellulase immobilization, with promising implications for lignocellulosic biorefinery.