(Fig. 3a). The specific OUR increased significantly, from the 2nd day to the 5th day, due to the metabolism activities including mycelia growth and degradation of dyes. Therefore, it increased as the activity of biomass increased (Fig. 3b). The higher specific OUR value of 0.82 mgO2/gTSS/minwas observed at the higher fungal activity (5th day of culture) corresponding to the high rate of decolonization (Fig. 3c) and COD removal (Fig.3d). After increasing the dye concentration in the ITE, OUR in the batch culture was higher. Therefore, increasing the indigo dye concentration up to 350 mg/L corresponding to about 700 mg equivalent COD/L has not a toxic effect on C. globosum. In contrast, it has a positive effect which results in high oxygen consumption. Previously, the evaluation of some fungal species for the
decolonization and degradation of textile dye has been also investigated with different dye concentrations. Synthetic dyes such as Reactive blue, Reactive orange, Ramazol black and Congo red were found to be decolorized with concentration ranging from 100 mg/L to 1000 mg/L by a mycelium of Polyporus rubidus (Dayaram and Dasgupta, 2008). They demonstrated that the fungal mycelia have advantage over the unicellular organisms by metabolizing the complex substrates by the production of enzymes. Due to an increased cell-to-surface ratio, fungi have a greater physical and enzymatic contact with the environment. The extracellular nature of the fungal enzymes is also advantageous in
tolerating high concentrations of the toxic-ants (Prachi and Anushree, 2009).