Stability Improvement of Immobilized a-amylase using Nano Pore Zeolite

Background: Enzyme engineering by immobilization techniques has proven to be well compatible with the other chemical or biological approaches aiming to improve enzyme’s functions and stability. Zeolites are porous alumino-silicates with a wide range of porosity and particle size along with the other remarkable properties such as high surface area, high stability against a wide range temperatures, pHs, as well as organic solvents. Objectives: Nano-zeolites are a class of advanced materials that have special properties that has made them ideal candidate for a wide range of applications. Materials and Methods: In this study, a nano-zeolite which has been synthesized and characterized in our previous work, was used to immobilize a-amylase and activated with glutaraldehyde as a bi-functional agent to improve enzyme properties. Results: Studies have shown an increased stability of the immobilized enzyme compared to the free enzyme against a range of temperature change and pHs as well. Also the stability of the immobilized enzyme was increased with respect to storage. The calculated binding efficiency shows that the immobilized a-amylase conserved 58.44 % of its native activity. Conclusions: Using nano pore zeolite for covalent attachment of the a-amylase resulted in an increased resistance of this enzyme against denaturation. The immobilized enzyme demonstrated higher stability compared to the free enzyme at higher temperatures and pH variations. Immobilization also caused an increase in the enzyme stability during storage.