Kinetic, Catalytic and Thermodynamic Properties of Immobilized Milk Clotting Enzyme on Activated Chitosan Polymer and its Application in Cheese Making

Abstract

Milk clotting enzyme (MCE) from Bacillus circulans 25 was immobilized by covalent binding, ionic binding and entrapment methods using various carriers. MCE covalently immobilized on activated chitosan polymer with the bifunctional agent glutaraldehyde (Ch-MCE) exhibited highest immobilization yield (74.6 %). Comparing to the native MCE, Ch-MCE exhibited higher optimum pH, higher optimum reaction temperature, lower activation energy, higher half-life time, lower deactivation rate constant and higher energy for denaturation. After immobilization, maximum reaction rate, Michaelis-Menten constant, specificity constant, turnover number, and catalytic efficiency of the enzyme were significantly changed. Calculated thermodynamic parameters for denaturation (enthalpy, entropy and Gibbs free energy) confirmed that the catalytic properties of MCE were significantly improved after immobilization. Reusability tests showed that after 7 catalytic cycles, the Ch-MCE retained about 71 % of its activity confirming its suitability for industrial applications.

Design, synthetic approach,in silicomolecular docking and antibacterial activity of quinazolin-2,4-dione hybrids bearing bioactive scaffolds

“…They were cultivated in Mueller Hinton broth at 35 ± 2 °C for 24 h. The antimicrobial activity and MIC were performed as reported by Qader et al (2021). 2,27–36…”