Optimization of medium for decolorization of Solar golden yellow R direct textile dye by Schizophyllum commune IBL-06

The ability of two new white rot fungi Schizophyllum commune IBL-06 and Ganoderma licidum IBL-05 to decolorize direct dye Solar golden yellow R was investigated using Kirk's basal salts medium. In initial time course study, the maximum decolorization (73%) of Solar golden yellow R was caused by S. commune IBL-06 after 6 days of incubation at pH 4.5 and 35 degrees C. Different parameters like incubation time, pH, temperature, and additional carbon and nitrogen sources were optimized to achieve maximum decolorization of Solar golden yellow R by S. commune IBL-06 in minimum possible time period. Supplementation of the medium with additional carbon sources enhanced dye decolorization to a variable extent. Addition of glucose gave the best results and caused a dramatic increase in decolorization; complete decolorization (100%) of the dye was achieved after only 2 days of incubation under optimum conditions. All the additional nitrogen sources showed an inhibitory effect on enzyme induction and dye decolorization. Manganese peroxidase (MnP) was found to be the major enzyme (764 U/ml) secreted by S. commune IBL-06 followed by laccase and only a minor activity of lignin peroxidase (LiP). The results suggest an excellent potential of S. commune IBL-06 for dye decolorization that can be enhanced by careful optimization of process parameters. (C) 2007 Elsevier Ltd. All rights reserved.