Screening and optimization of media constituents for decolourization of Mordant Blue-9 dye by Phanerochaete chrysosporium

Abstract

Decolourization of Mordant Blue-9 (MB-9) by the white-rot fungi Phanerochaete chrysosporium MTCC 787 was investigated by screening and optimization of the media constituents used for growing the fungus. Both % decolourization and specific removal of MB-9 by the fungus were taken as the responses to screen and optimize the media constituents using statistically valid Plackett–Burman and response surface methodology (RSM) design of experiments, respectively. Amongst the media constituents screened, glucose, veratryl alcohol, KH2PO4 and CaCl2 were selected as the most important (P value < 0.05) media constituents for MB-9 dye decolourization; the other media constituents, viz. MgSO4, tween 20, NH4Cl2 and inoculum size were, however, found to be insignificant in the study. Central composite design followed by RSM used in optimizing the important media constituents for enhancing the decolourization of MB-9 dye revealed optimum combinations of glucose, 13.46 g l−1; veratryl alcohol, 9.30 mM; KH2PO4, 24.52 g l−1; CaCl2, 2.18 g l−1; MgSO4, 9.89 g l−1; NH4Cl2, 4.68 g l−1; tween 20, 0.050% and inoculum size, 0.8 OD650, which gave a maximum % dye decolourization of 100% and specific dye removal of 0.1571 mg U−1.