Decolorization of simulated textile dye baths by crude laccases from Trametes hirsuta and Cerrena unicolor

In this study crude laccases from the white-rot fungi Cerrena unicolor andTrametes hirsuta were tested for their ability to decolorize simulated textile dyebaths. The dyes used were Remazol Brilliant Blue R (RBBR) (100mg/L), CongoRed (12.5mg/L), Lanaset Grey (75mg/L) and Poly R-478 (50mg/L). The effect ofredox mediators on dye decolorization by laccases was also assessed. C. unicolorlaccase was able to decolorize all the dyes tested. It was especially effective towardsCongo Red and RBBR with 91 and 80% of color removal in 19.5h despite the factthat simulated textile dye baths were used. Also Poly R-478 and Lanaset Grey werepartially decolorized (69 and 48%, respectively). C. unicolor laccase did not needany mediators for removing the dyes. However, T. hirsuta laccase was only able todecolorize simulated Congo Red and RBBR dye baths (91 and 45%, respectively)in 19.5h without mediators. When using mediators the decolorization capabilitywas enhanced substantially, e.g. Poly R-478 was decolorized by 78% in 25.5h. Onthe whole, both laccases showed potential to be used in industrial applications.