Immobilized enzymes are useful as reusable catalysts in industrial processes. In this study, -amylase
was used as a model enzyme to evaluate the propensity of synthesized porous chitosan microspheres
as immobilization matrix. Chitosan microspheres were synthesized by grafting and covalent gelation
technique using acrylamide (AAm) and glutaraldehyde (GA) as chemical agents, respectively. The
synthesized chitosan-cl-poly(AAm) demonstrated amylase immobilization capacity of 350 mg/g. Furthermore,
SEM results supported the porous microsphere structure for chitosan-cl-poly(AAm) with
non-aggregated amylase immobilization, which accounts for comparable activity of immobilized amylase
(3.28 mol/ml/min) in contrast to free amylase (3.46 mol/ml/min). The immobilized -amylase
was characterized for optimal pH and temperature activity and showed better resistance to temperature
and pH inactivation in contrast to free amylase. The immobilized amylase retained more than 60% of its
initial activity when stored at 4 ◦C for 30 days and retained 50% of its initial activity after seven successive
repeated-use cycles. In conclusion, the study can be used as base for the immobilization of competent
industrial biocatalysts in non-aggregated active structure.