Characterization of a solvent, surfactant and temperature-tolerant laccase from Pleurotus sp. MAK-II and its dye decolorizing property.

Objective: Laccase is industrially important but a major challenge is the production of an ideal laccase with suitable physicochemical properties to tolerate temperature, surfactants, metal ions and solvents towards its potential application in bioremediation.

Results: A laccase with a molecular mass of 43 kDa was purified from Pleurotus sp. MAK-II. It was optimally active at pH 4.5 and 60 °C using ABTS (2,2'-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) as substrate. The laccase was susceptible to NaN3 and NaCN. Activity was strongly enhanced by Cu(2+), Mg(2+) and Ca(2+). The purified laccase showed stability towards various surfactants and solvents and decolorized, in the presence of violuric acid as redox mediator, the diazo dye Congo Red and the anthraquinone dye Remazol Brilliant Blue R to the extent of 96 and 72 %, respectively.

Conclusion: The ideal physicochemical properties of Pleurotus sp. MAK-II-derived laccase suggest that it could be effectively used in the textile dye industry.