Biodegradation of methylene blue and carbaryl by <i>Trametes versicolor</i> laccase preparations in the presence of a mediator compound

Laccase from Trametes versicolar was immobilized on to acrylate based microbeads carrying epoxy or carbonate groups. The amounts of immobilized enzyme on the carbonate and epoxy groups were 24.6 and 9.7 mg/g, respectively. In the presence of a mediator (i.e., acetosyringone) almost 100% biodegradation was observed for both Methylene Blue dye (MB) and Carbaryl pesticide (CP) by the immobilized laccases, while in the absence of mediator, 63 and 71%, respectively. The immobilized enzyme was operated in a fluidized bed reactor for biodegradation of MB and CP for 24 h, and the initial activity lost was only 8.0 and 2.0%, respectively. The data show that the immobilized enzyme can effectively be utilized for complete degradation of organic pollutants in wastewaters.