Abstract

ENHANCED BIOCATALYTIC ESTERIFICATION WITH LIPASE-IMMOBILIZED GLUTARALDEHYDE CROSSLINKED CHITOSAN BEADS.

Naureen Khan, Mohsin Maseet and Seemi F. Basir*

ABSTRACT

Lipase from porcine pancreas was immobilized onto glutaraldehyde cross linked chitosan beads. This was to markedly improve the performance of the enzyme. Lipase catalyzed esterification is a vital reaction because of its useful ester products so it requires efficient methods to immobilize the enzyme, yielding a biocatalyst with high activity and stability compared to free lipase. Immobilized lipase was characterized for optimum functional range and stability with respect to pH and temperature. The chitosan immobilized lipase has a broad range of pH and thermal stability. The effects of substrate concentration and reusability of immobilized beads were also studied. In addition, this work involved a process for the preparation of the reaction medium consisting of lauric acid and oleyl alcohol as reactants and hexane as a solvent for estimation of esterification. The structural morphology of cross linkable structure of chitosan with glutaraldehyde were studied by Scanning electron microscopy (SEM), Energy Dispersive X-ray (EDX), Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). Further, the lipase incorporation on the beads was confirmed by a thermo-gravimetric analysis. The overall esterification was 78% at 40ºC.

Keywords: Chitosan, glutaraldehyde, Lipase, immobilization, FTIR, XRD, SEM, TGA and EDX.