Synthetic dyes are extensively used in textile dyeing, paper, printing, colour, photography, pharmaceutics, cosmetics and other industries. Among these, azodyes represents the largest and most versatile class of synthetic dyes. Approximately 10-15% of the dyes are released into the environment during manufacture and usage. Traditional methods of treatment are found to be expensive and have operational problems. Biological decolourization has been investigated as a method to transform, degrade or mineralize azo dyes. In the present studies bacteria from soil from dye waste area were subjected for acclimatization to C.I. Reactive yellow 145, an azo dye in the basal nutrient media.The most promising bacterial isolate was used for further dye degradation studies. The 16s r RNA gene sequencing revealed the isolated organism as Enterococcus faecalis strain YZ66. The strain showed complete decolourization of the selected dye (Reactive yellow 145- 50 mg/L) within 10 hours in static anoxic condition. The optimum pH and temperature for the decolourization was 5.0 and 370C respectively. The biodegradation was monitored by UV-Vis, TLC and HPLC. Toxicity study demonstrated no toxicity of the biodegraded product. The results suggest that the isolated organism Enterococcus faecalis strain YZ 66 as a useful tool to treat waste water containing reactive dyes.
