A mixed anaerobic bacterial culture decolorized Drimaren Orange K-GL, Everzol Red RBN and Everdirect Supra Yellow PG dyestuffs at 200 mg dyestuff l(-1) over 24 h. Improved performance with complete decolorization within 24 h was achieved by incubation with 5 g yeast extract l(-1) compared to glucose, lactose and sucrose though 50 mg yeast extract l(-1) supplemented with 5 g lactose l(-1) or 5 g sucrose l(-1) also resulted in complete decolorization within 24 h.