Chitosanase could cleaveβ-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.Enz...Chitosanase could cleaveβ-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 Fe_(3)O_(4)-SiO_(2) 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 de-termined with temperature and pH,and the thermal-and 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.展开更多
基金supported by the National Key Research and Development Program of China(No.2019 YFD0901902)the National Natural Science Foundation of China(No.31801574)+1 种基金the Central Public-interest Scientific Institution Basal Research Fund,YSFRI,CAFS(No.20603022021020)Qingdao Science and Technology Demonstration and Guidance Project for Benefiting the People(No.20-3-4-28-nsh).
文摘Chitosanase could cleaveβ-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 Fe_(3)O_(4)-SiO_(2) 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 de-termined with temperature and pH,and the thermal-and 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.