Removal of 2,4-dichlorophenol by chitosan-immobilized laccase from Coriolus versicolor

Laccase from Coriolus versicolor was immobilized on chitosan using glutaraldehyde as a cross-linking agent. After immobilization, laccase retained 52.2% of its original activity and was used to study 2,4-dichlorophenol (2,4-DCP) removal from aqueous solutions. The optimum pH for 2,4-DCP removal by the immobilized laccase was ∼5.5, which was lower than the optimal pH of 6.0 for free laccase catalysis. Immobilized laccase also had an atypically wide optimum temperature range for catalysis of 35–45 °C. Immobilized laccase could be used repeatedly, and its removal efficiency for 2,4-DCP remained above ∼50% for up to six usages.