Characterization of laccase from a novel isolated white-rot fungi Trametes sp. MA-X01 and its potential application in dye decolorization

Abstract

A novel laccase from a newly isolated white-rot fungus Trametes sp. MA-X01 was characterized. The sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) showed that the molecular weight of the laccase produced by Trametes sp. MA-X01 in liquid medium was approximately 62 kDa. The optimal temperature was 60 °C. The enzyme was quite stable at high temperature and maintained about 85% of its highest activity after incubation at 60 °C for 2 h. The laccase could work efficiently over a wide pH range (3.0–5.0) with no significant difference in enzyme activity. Among the metals tested, Mg2+, Mn2+, Zn2+ and Cu2+ could promote the laccase activity, whereas the laccase activity was strongly inhibited by β-mercaptoethanol, l-cysteine and dithiothreitol. Furthermore, the laccase from Trametes sp. MA-X01 exhibited strong ability to decolorize different structural dyes, including azo, heterocyclic and triphenylmethane dyes, in the absence of a redox mediator.