The aliquot (3 ml) of the culture media was withdrawnat different time intervals, centrifuged at 6000 g for20 min and the decolourization was determined by measuringthe change in absorbance of culture supernatantsat kmax of the respective dyes. Change in pH and reductionin COD (APHA 1995) was studied during Brown3REL decolourization. Growth of micro-organism in dyecontaining medium was determined by the gravimetricmethod, after drying at 80_C until constant weight. Thepercentage of decolourization (Saratale et al. 2006) andaverage decolourization rate (ADR) (Khehra et al. 2005)were measured at different time intervals. All decolourizationexperiments were performed in triplicate. Abioticcontrols (without micro-organisms) were alwaysincluded. The ADR was calculated as follows:

where, C = initial concentration of dye (mg l)l),%D = dye decolourization (%) after time t.