Immobilization of laccase on Sepharose-linked antibody support for decolourization of phenol red.

Laccases which are considered as "green tools" in biotechnology have potential to degrade toxic contaminants/synthetic dyes present in industrial effluents. The loss in activity and stability of laccases are key challenges faced in their potential industrial applications. Here, laccase from Trametes versicolor (polypore mushroom) was immobilized on Sepharose-linked antibody support to carry out the decolourization of phenol red. This support was prepared by covalent linking of anti-laccase antibodies to CNBr activated Sepharose at pH 8.5, and then laccase was immobilized on this affinity support at pH 5.0. The amount of laccase immobilized was approximately 33 mg per gram of the affinity support, giving an immobilization yield of 83.4%. The immobilized enzyme displayed an activity of 3.88 U with an effectiveness factor (η) of 0.90. Immobilization of laccase led to significant enhancement in thermal and storage stability. The immobilized enzyme retained 44% of its activity after 10 cycles of continuous use. The decolourization of phenol red dye obtained by immobilized and soluble laccase after 6 h of incubation at 50 °C was 80 and 56%, respectively. Thus, immobilization of laccase on Sepharose-linked antibody support leads to remarkable improvement in its various properties, making it more versatile for industrial applications.