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] .

Automated summary

The aim of this study was to investigate and identify the optimal conditions for immobilizing peroxidase on chitosan-decorated alumina-zirconia-titania composites (AZT) activated with glutaraldehyde. Response surface methodology was used to optimize the immobilization conditions, and the results showed that the best immobilization efficiency and enzyme activity were achieved with 40 mg of AZT composites, 1.5% glutaraldehyde, 200 units of enzyme, and a pH of 6.5. The mineralogical structure of the prepared AZT and CS/AZT was studied using X-ray diffraction patterns, while scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy were used to analyze the morphological and chemical properties of the immobilized peroxidase on CS/AZT. The study also found that the immobilized peroxidase exhibited a residual activity of 85% after 15 repetitions, and the residual activity of both immobilized and free enzymes after 12 weeks of storage was 81% and 32% of their initial activity, respectively. Based on these findings, it can be concluded that peroxidase immobilization technology is promising for industrial applications.