Using Ceriporiopsis subvermispora CZ-3 laccase for indigo carmine decolourization and denim bleaching

• Melon peel is appropriate support material for the laccase production by Ceriporiopsis subvermispora.
• C. subvermispora laccase is more effective on dye decolourization than denim bleaching with or without mediator.
• Almost all of the compounds selected have mediator effect on indigo carmine decolourization.
• Only HBT and MS have mediator effect on denim bleaching with C. subvermispora laccase.

In this study, the production of laccase by Ceriporiopsis subvermispora CZ-3 has been studied under semi solid-state conditions using natural waste as solid support materials. Different concentrations of xylidine derivatives were also investigated as inducer affecting laccase production. Melon peel having the lowest C/N ratio in comparison to other supports led to the highest activity levels, reaching maximum values of about 3000 UL−1 for C. subvermispora CZ-3 in the presence of 2,4-xylidine. Laccase produced by this fungus was partially purified by ammonium sulphate precipitation and Sephacryl S-100 HR size exclusion chromatography. Several kinetic parameters of enzyme were also determined with 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonate) as a substrate. On the other hand, several compounds were investigated with respect to mediator effect for decolourization of indigo carmine and denim bleaching by this enzyme. It was observed that most of the compounds have mediator effect for decolourization of indigo carmine whereas 1-hydroxybenzotriazol is an appropriate compound for indigo dyed denim bleaching.