Purification of the laccase protein. The culture supernatant of P. pastoris harboring pPICHOLI-Lacc was collected by centrifugation at 2,500 ×g for 10 min. The supernatant was precipitated by ammonium sulfate fractionation. The precipitant was dissolved in phosphate buffered saliine buffer and then loaded onto a DEAESephadex column (Amersham Biosciences). The bound protein was eluted by NaCl gradient in 30 mM sodium phosphate buffer (pH 7.0). The flow rate was 1 mL/min.