Abstract
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► Electrospinning and functionalized of poly (AN-co-MMA) nanofibers. ► Activation of poly (AN-co-MMA) nanofibers surface for covalent immobilization. ► Study the factor effect on the surface modification with glutaraldehyde. ► Effect of pH, storage, and operational stability on the immobilized enzyme.
β-Galactosidase from Aspergillus oryzae was immobilized on amino functionalized poly (Acrylonitrile-co-Methyl methacrylate) poly (AN-co-MMA) nanofibers using glutaraldehyde. Among the four different factor used for activation, the activation of poly (AN-co-MMA) nanofibers by glutaraldehyde followed by covalent enzyme on activated support could stabilize the enzyme β-galactosidase and was found to be effective. Different factors affecting the activation process were investigated and their impact on the activity and the retention of immobilized enzyme's activity was monitored. Concentration of glutaraldehyde and activation temperature, time, and activation pH were found of a determined effect. The optimum concentration, reaction time, reaction temperatures, and activation pH value of glutaraldehyde are 5.0, 180min, 65°C and 11.0, respectively. The scanning electron micrographs showed the change on the poly (AN-co-MMA) nanofibers surface revealing the successful immobilization of β-galactosidase. Thermal and pH stabilities were found to be increased upon immobilization. The immobilized β-galactosidase had better resistance to temperature and pH inactivation than did the free form. Finally, the immobilized β-galactosidase retained 35% of its initial activity when stored at 4°C for 70days and retained 64% of its initial activity after ten consecutive reactor batch cycles.