Muhammad Asgher
University of Agriculture, Pakistan
Title: Activity and thermostabilty improvement of Trametes versicolor IBL-04 laccase by chitosan beads immobilization
Biography
Biography: Muhammad Asgher
Abstract
The laccase enzyme has got tremendous applications in diverse industrial processes including biomass delignification, bio pulping in paper and pulp, as denim stone wash agent, detergents, bioremediation and biosensor development. Monomeric 66 kDa laccase produced by Trametes versicolor IBL-04 in SSF of corncobs (911 U/mL) was purified through ammonium sulphate precipitation, dialysis, ion-exchange chromatography and gel filtration. The purified laccase was immobilization using chitosan as support material and glutaraldehyde as activator/cross linking agent. Chitosan concentration of 2.5% was optimum for preparation of most stable 2.0 mm size chitosan beads activated by 1.5% glutaraldehyde for best laccse immobilization. Scanning electron microscopy showed that beads with immobilized laccase on the surface were spherical in shape having large surface area. The immobilized laccase was found to be catalytically more vigorous and stable and it worked over a wide range of pH 3-6 and temperature 45-65o C. Laccase immobilized with chitosan beads had 936 U/mL at pH 6 and 60° C and improved thermal behavior. The chitosan beads immobilized laccase had higher Km (93 µM) and V-max 944 µM/min values as compared to its soluble counterpart thus demonstrating its higher catalytic efficiency. The kinetic and thermostability characteristics of chitosan beads immobilized laccase reflect that the enzyme has potential for use in industrial and environmental biotechnology.
