Phanerochaete chrysosporium IBL-03 secretes high titers of manganese peroxidase during decolorization of Drimarine Blue K2RL textile dye.

A novel indigenous strain, Phanerochaete chrysosporium IBL-03, with high manganese peroxidase (MnP) activities was used for decolorization of a reactive textile dye, Drimarine Blue K2R, which is used extensively in textile units of Pakistan. The initial experiment was run for seven days with 0.01% (w/v) dye solution prepared in Kirk's basal nutrient medium. Samples were removed after every 24 h and the extent of dye decolorization was determined at lambda(max) of the dye. The study revealed that P. chrysosporium caused 65% decolorization of Drimarine Blue K2RL in seven days. By process optimization, 97% colour removal could be achieved in three days using 0.005% (w/v) Drimarine Blue K2RL solution at pH 4.0 and 30 degrees C in defined Kirk's medium with 0.9% (w/v) molasses and 0.2% (w/v) ammonium dihydrogen phosphate added as carbon and nitrogen sources, respectively. Manganese peroxidase was found to be the major enzyme (560 IU/mL) involved in dye decolorization of Drimarine Blue K2RL by P. chrysosporium. The dye adsorption studies showed that the dye initially adsorbed on fungal mats disappeared later on, possibly by the action of MnP secreted by the fungus in secondary metabolism.