Immobilization of cellulase enzyme complex to magnetic particles

In recent years there has been an increasing interest in the use of magnetic nanoparticles as support material in enzyme immobilization. In this study, covalent immobilization of cellulase enzyme complex was carried out by using magnetite (Fe3O4) synthesized by co-precipitation method as support material. The synthesized magnetic nanoparticles were coated with silane to stabilize the magnetic nanoparticles (A-MNP). Surface modification The magnetic particles coated with APTES were activated with glutaraldehyde (G-MNP) followed by cellulase enzyme immobilization (E-MNP). SEM, EDX. FTIR analyzes were used for the characterization of MNP, A-MNP, G-MNP and E-MNP. The approximate size of MNPs was found to be 200 nm. Maximum activity of free and immobilized cellulase enzymes was determined at 70 °C. The optimum pH values were 5 and 4,8 for immobilized enzyme, free enzyme, respectively. Residual enzyme activity was determined as 29,9 % and 38 % for free and immobilized cellulase enzymes, respectively, after 5 hours at 60 °C. The cellulase activities measured at different substrate concentrations. Km, Vmax values were calculated as 155,25 mg/ml, 2500 μmol/ml.dk and 23,64 mg/ml, 108,69 μmol/ml.dk for free and immobilized cellulase enzyme, respectively. To investigate the reusability of the immobilized cellulase enzyme, the CMC method was used and it was determined that enzyme activity was maintained at 20% at the end of the 4th loop. The stability of free and immobilized cellulase enzymes was determined to be 73.3 % and 91.2 %, respectively, at the end of 20 days at 4 °C. The sugar yields obtained by the enzymatic hydrolysis of the physically and chemically pretreated waste papers with the free and immobilized cellulase enzyme for 48 hours. Glucose yields were found as 10,2 % for 0,25 g waste newspaper and 8,19 % for 0,5 g waste newspaper for free enzyme. Glucose yields were found as 3,87 % for 0,25 g waste newspaper and 3,27 % for 0,5 g waste newspaper in the immobilized cellulase enzyme.