Optimization of Biocatalytic Steps via Response Surface Methodology to Produce Immobilized Peroxidase on Chitosan-Decorated AZT Composites for Enhanced Reusability and Storage Stability

The aim of this work is to study and identify the best conditions for peroxidase immobilization on chitosan (CS)-decorated Alumina-Zirconia-Titania composites (AZT) activated with glutaraldehyde. A statistical method such as response surface methodology was used to carry out the optimization investigation based on AZT composites, the concentration ranges (20-80 mg), glutaraldehyde concentrations (0.5-3.5%), enzyme (50-200 units), and pH (5.5-8.5). The system achieved a maximum immobilization efficiency of 91.3% against 91.92%, and maximum enzyme activity was 181.26 vs. 182.6 unit/g of the predicted and actual results, respectively. These values were obtained using 40 mg of AZT composites, 1.5% of glutaraldehyde, 200 units of enzyme, and pH 6.5. X-ray diffraction patterns were used to study the mineralogical structure of the prepared AZT and CS/AZT. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy were used to investigate and characterize the morphological/chemical properties of the immobilized peroxidase on CS/AZT. After 15 repetitions, the residual immobilized peroxidase activity was found to be 85%. The residual activity of immobilized and free enzymes after 12 weeks of storage at 4 degrees C was determined to be 81% and 32% of their initial activity, respectively. As a result of all the above-mentioned properties and values, it is possible to conclude that adopting technology for peroxidase immobilization is promising and plays a role in the field of industrial applications. [GRAPHICS] .