Simulation of Enzyme Catalysis in Calcium Alginate Beads

Abstract

In the present study, a general mathematical model for a fixed bed–immobilized enzymereactor was developedto simulate the process of diffusion and reaction inside the biocatalyst particle. The modeling and simulation of starch hydrolysis using immobilized α–amylase was used as a model for this study. Corn starch hydrolysis was carried out at constant pH of 5.5 and temperature of 50°C. The substrate flowrate was ranging from 0.2 – 5.0 ml/min, substrate initial concentrations 1 to 100 g/L. α–amylase was immobilized on to calcium alginate hydro-gel beads of 2mm average diameter.In this work Michaelis–Menten kinetics has been considered. The effect of substrate flow rate (i.e. residence time) and initial concentration on intra-particle diffusion has been taking into consideration. The performance of the system is found to be affected by the substrate flow rate and initial concentrations. The reaction is controlled by the reaction rate. The model equation was a non-linear second order differential equation simulated based on the experimental data for steady state condition. The simulation was achieved numerically using FINITE ELEMENTS in MATLABSoftware package. The simulated results give satisfactory results for substrate and product concentration profile within the biocatalyst bead.