Abstract: Myrothecium verrucaria has the advantages of short growth cycle and high enzyme activity of secreting laccase. In this study, the crude enzyme was produced by the M. verrucaria GH-01 obtained by separation. Further we purified the crude enzyme by fractional precipitation, dialysis and chromatography. The results of SDS-PAGE and Native-PAGE indicated that the monosome protein with laccase activity was obtained by purification. The study of enzymatic properties of laccase showed that the optimal temperature of catalyzed reaction for laccase was 40℃, and the laccase activity against ABTS showed a maximum at pH4.0. It had the favorable stability under the low temperature and alkaline conditions. Besides, studying the laccase decolorizing of 4 representative dyes demonstrated that the laccase decolorizing rate for orange I of azo dyes and alizarin red of anthraquinone class was the highest with decolorizing rate over 80% by 1 h, lower for fuchsin of triphenylmethane class with decolorizing rate only 20% and lowest for methylene blue of heterocyclic class. In 10 U laccase system, the decolorizing degree of the 50mg/L dye concentration was optimal.

Key words: Myrothecium verrucaria GH-01, purification, enzymatic properties