In the current study, Fe3O4 nanoparticles were synthesized and coated with chitosan. Chitosan was linked to the endoglucanase by glutaraldehyde. The endoglucanase was extracted from the symbiotic bacterium Bacillus safensis CF99 in the gastrointestinal tract of Osphranteria coerulescens larvae. The results of XRD analysis showed that the crystal structure of Fe3O4 is stable even after coating with chitosan and binding to the enzyme. The immobilization process was confirmed by VSM, TG, FT-IR, FE-SEM, and EDX analyses. The sizes of Fe3O4, Fe3O4– chitosan, and the immobilized enzyme were calculated to be 26.98 nm, 32.08 nm, and 33.11 nm, respectively. Loading efficiency and residual activity were obtained to be 78.2% and 67.7%, respectively. The amount of immobilized enzyme on the support was 101.3 mg/g. The optimum pH and temperature of the immobilized enzyme were estimated 8.5 and 50 °C, respectively. The half-life of the immobilized enzyme under the best conditions was 240 min. The Vmax and Km of immobilized enzyme were obtained to be 51.29 ± 1.787 μmol/min and 0.5521 ± 0.1249 mg/ml, respectively. After reusing the enzyme ten times, 77% of its activity remained. In conclusion, the immobilized enzyme has remarkable activity in a wider range of temperatures and pH and is potentially suitable to use in bioethanol production and detergent or other industries.

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