The lowest protein content was recorded when manitole was used as the carbon source in decolorization process. Starch was also the best co-substrate by using a carbon source in the decolorization of direct blue 75 by Com. acidovorns-TN1 & Bur. cepace-TN5, followed by glu- cose and then fructose in the case of decolorization by Com. acidovorns-TN1, and glucose followed by fructose in case of decolorization by Bur. cepace-TN5.