Covalent Immobilization of Trametes polyzona H18 Laccase Enzyme on Activated Carbon for Synthetic Dye Decolorization

Abstract

Laccase has a promising potential to be used as a bioremediation agent.  In the present study, crude laccase produced by Trametes polyzona H18 isolated from Batam Botanical Garden, Batam Island was successfully immobilized on activated carbon and tested for Reactive Black 5 (RB5) dye decolorization. Activated carbon is recognized for its excellent adsorption capabilities, resulting from its extensive internal surface area and cavities, which enhance its adsorption capacity. Activated carbon was made from oil palm empty fruit bunches (OPEFB) through the pyrolysis process and modified by covalent binding using 3-aminopropyl-triethoxysilane (APTS) in variations of 5, 10, and 15% (v/v).  Results showed that the highest immobilized laccase-activated carbon yield was 50.44% obtained by activated carbon modified by 15% (v/v) of APTS. The immobilized laccase-activated carbon improved the RB5 decolorization rate by 87.5 % compared to free laccase, which was only 35.5 % at 4 h of reaction time. These preliminary results suggested that immobilized laccase on activated carbon can be potentially developed for large-scale bioremediation of other synthetic dyes.