Decolorization of diazo-dye Reactive Blue 172 by Pseudomonas aeruginosa NBAR12

A novel bacterial strain capable of decolorizing textile dyes was isolated from dye contaminated soil obtained from industrial estate of Ahmedabad, Gujarat, India. The bacterial isolate Pseudomonas aeruginosa NBAR12 was capable of decolorizing 12 different dyes tested with decolorization efficiency varying in the range of 80 to 95%. Maximum extent as well as rate of Reactive Blue 172 (RB 172) decolorization was observed when glucose (2 g x l(-1)) and yeast extract (2.5 g x l(-1)) were supplemented in the medium. The optimum dye pH and temperature for dye decolorization was found to be 7 and 40 degrees C, respectively. The decolorizing activity was found to increase with increasing the dye concentration from 50 to 400 mg x l(-1). The dye decolorization was strongly inhibited at 500 mg dye l(-1) in the medium. High performance thin layer chromatography analysis indicated that dye decolorization occurred due to the breakdown of dye molecules into colorless end products.