Decolorization of synthetic melanins by crude laccases of Lentinus polychrous Lév

Melanins are complex natural pigments that darken the skin and are difficult to degrade. This study evaluated synthetic melanin decolorization by the crude laccase from fungus Lentinus polychrous in the absence and presence of selected redox mediators. The greatest melanin decolorization activity was 87 % at pH 6.5 within 3 h in the presence of 2,2-azinobis (3-ethylbenzothiazoline-6-sulfonate) diammonium salt (ABTS), whereas only about 22 % melanin decolorized at pH 5.0 in case of no mediator. The optimum temperatures for melanin decolorization in the absence and presence of ABTS were 55 and 35°C, respectively. Using a natural redox mediator, 1.0 mmol/L vanillin leads to 45 % melanin decolorization. Our results suggest the possibility of applying vanillin for L. polychrous laccase-catalyzed decolorization of melanin.