Optimization of Factors Affecting Decolourization of Sulphonated Azo Dye Red HE7b in vitro by bacillus Sp. Azo1

A zo dyes are widely used organic molecules that are generally recalcitrant to biodegradation, thus causing environmental pollution. In this study, the effect of various growth conditions like temperature, pH, dye concentration, aeration and presence/absence of co-substrate on decolourization of azo dye Red HE7B by Bacillus sp. Azo1 has been determined. Decolourization of the dye was achieved under static condition. Optimum decolourization of Red HE7B was observed at 30°C and 50 mg/l dye concentration, where more than 90% decolourization was achieved within three days of inoculation. Bacillus sp. Azo1 could decolourize the dye through a range of pH values from 6 to 9. Presence of co-substrate limited the decolourization with glucose being the most potential inhibitor. Identification of factors influencing decolourization will help in rapid removal of these pollutants from contaminated habitat.