Immobilization of Chitosanase on Magnetic Nanoparticles: Preparation, Characterization and Properties

Chitosanase could cleave β-1, 4-linkage of chitosan to produce chitooligosaccharides (COS) with diverse biological activities. However, there are many limitations on the use of free chitosanase in industrial production. Enzyme immobilization is generally considered a valuable strategy in industrial-scale applications. In this study, the chitosanase Csn-BAC from Bacillus sp. MD-5 was immobilized on Fe₃O₄-SiO₂ magnetic nanoparticles (MNPs) to enhance its properties, which could be recovered easily from reaction media using magnetic separation. The activities of Csn-BAC immobilized with MNPs (MNPs@Csn-BAC) were determined with temperature and pH, and the thermaland pH-stabilities, respectively. The reusability of the MNPs@Csn-BAC was determined in repeated reaction cycles. Immobilization enhanced the thermal and pH stability of Csn-BAC compared with the free enzyme. After eight reaction cycles using MNPs@Csn-BAC, the residual enzyme activity was 72.15%. Finally, the amount of COS released by MNPs@Csn-BAC was 1.86 times higher than that of the free Csn-BAC in the catalytic performance experiment. The immobilized Csn-BAC exhibits broad application prospects in the production of COS.