Characterization of a Laccase from White Rot Fungus <i>Cerrena unicolor</i>

Abstract

Dyes are usually difficult to be decolorized due to their complex chemical structures. In this work, laccase was purified from the white rot fungus Cerrena unicolor to evaluate its application in dye decolorization. SDS-PAGE analysis showed the purified laccase to be a monomeric protein of 63.7 kDa. The optimum pH for the oxidation of 2,2-azinobis-(3-ethylbenzthiaoline-6-sufonic acid) (ABTS) was 2.2 and the optimum temperature was 50°C. The activity of the purified enzyme was strongly inhibited by sodium azide and partially inhibited by cysteine, dithiothreitol. The Km values of the purified laccase for the substrate ABTS, syringaldazine and 2,6-dimethoxyphenol were 0.217, 0.306 and 0.199 mmol/L.