Stability of immobilized porcine pancreas lipase on mesoporous chitosan beads: A comparative study

Publication date: Available online 11 August 2016 Source:Journal of Molecular Catalysis B: Enzymatic Author(s): Saeedeh L. Gilani, Ghasem D. Najafpour, Aliakbar Moghadamnia, AzlinaHarun Kamaruddin Porcine pancreas lipase was immobilized on mesoporous chitosan beads. Glutaraldehyde as coupling agent was used through several immobilization techniques. With the aid of FESEM, BET and BJH analysis, the effect of glutaraldehyde on porosity of chitosan was evaluated. It was observed that the total surface area and pore volume of the carrier were significantly improved by addition of glutaraldehyde as cross-linking agent. The surface area exposure and pore volume were substantially increased (both by 4.4 folds). In addition, distribution of enzyme on the carrier was illustrated by fluorescence image. The characteristics of the immobilized lipases such as immobilization efficiency, enzyme activity, pH stability, thermal stability, reusability, storage stability and enzyme leakage were evaluated. In kinetic studies of enzyme, Michaelis–Menten kinetic coefficients of the hydrolytic activity for the immobilized lipase were defined using Lineweaver–Burk plot. The low value of ionization constant, Km (∼0.008mM) and high value of specific rate, Vmax(∼200μM/ml.min) indicate strong affinity and high activity of enzyme. The obtained results demonstrate that use of glutaraldehyde has an excellent impact on expansion of the porosity of chitosan and enzyme distribution. The immobil...

Source: Journal of Molecular Catalysis B: Enzymatic - August 11, 2016 Category: Biochemistry Source Type: research