BIODEGRADATION OF THE AZO DYE (REMAZOL BLACK B) BY Pseudomonas putida ISOLATED FROM TEXTILE WASTEWATER SAMPLE

Abstract

The synthetic aromatic compounds, Azo dyes, which have one or more -N=Ngroups, are the most important and largest class of the used dyes with commercial applications especially in food and textile industries. The cleaning of textile wastewater containing dyes has attracted much attention in the recent years. The present study is an attempt to determine the ability of some bacterial isolates obtained from textile wastewater sample from Al Khumra station for decolorization of the Azo dye, Remazol black B. Three bacterial isolates were isolated from wastewater of textile effluents containing azo dye on basal nutrient medium. These isolated bacterial isolates were identified as Bacillus cereus, B. pumilus and Pseudomonas putida by phylogenetic analysis of their 16S rDNA. The most promising bacterial isolate was Pseudomonas putida and was used for further study. Results of study revealed that P. putida have ability of complete biodegradation (100%), if concentration is at 400 ppm while this degradation was 60 and 30 percent at 600 and 700 ppm concentration of azo dye respectively. Further, rate of biodegradation also depend on the pH and temperature of the surrounding medium, at 400 ppm concentration of azo dye, maximum degradation was obtained at pH 6.5 and temperature 40°C. This decolorization potential increased the applicability of this bacterium for the dye removal and the results suggest that the obtained isolate of P. putida can be used as a useful tool to treat waste water containing Azo dyes. Degradation potential of the bacterium depend on the presence of azoreductases, laccases and peroxidases enzymes.