Decolorization of dyes by a purified laccase from Coprinus comatus

An inky cap, Coprinus comatus synthesizes and secretes a laccase in the liquid yeast extract peptone dextrose medium. We have successfully purified the enzyme through the ionexchange chromatography and the preparative gel electrophoresis. The estimated molecular weight was 67 kDa by the SDS-PAGE analysis. Optimum pH was pH 4.3 and optimum temperature was 25°C. The Km value was 0.45 mM and the Vmax was 0.0132 OD/min/unit for o-tolidine. Purified laccase showed 49.3% decolorizing activity against remazol brilliant blue R (RBBR) and 41.6% decolorizing activity against Poly R-478 after 12 h incubation.