Immobilization of fungal (Trametes versicolor) laccase onto Amberlite IR-120 H beads: Optimization and characterization

Laccase from Trametes versicolor was immobilized on Amberlite IR-120 H beads. Maximum immobilization obtained was 78.7% at pH = 4.5 and temperature T = 45 degrees C. Kinetic parameters, K-m and V-max values, were determined respectively as 0.051 mM and 2.77 x 10(-2) mM/s for free and 4.70 mM and 5.27 x 10(-3) mM/s for immobilized laccase. The Amberlite-laccase system showed a 30% residual activity after 7 cycles. On the other hand, the loss of activity for free laccase after 7 days of storage at 4 degrees C was 18.5% in comparison to Amberlite-laccase system with a loss of 1.4%, during the same period. Improved operational, thermal and storage stabilities of the immobilized laccase were obtained compared to the free counterpart. Therefore, the use of low-cost matrices, like Amberlite for enzyme immobilization represents a promising product for enzymatic industrial applications. (C) 2012 Elsevier Ltd. All rights reserved.