ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Immobilization of endoglucanase isolated from symbiotic bacterium Bacillus safensis CF99 on magnetic nanoparticles

Mohammad Ehsan Salehi and Ahmad Asoodeh

Department of Chemistry, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, Iran

E-mail: Asoodeh@um.ac.ir

Received: 1 February 2022  Accepted: 22 June 2022

Abstract:

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 V_max and K_m 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.

Keywords: Immobilization; Endoglucanase; Magnetic nanoparticles

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-022-02342-6

Chemical Papers 76 (10) 6523–6536 (2022)