Biodegradation of Allura Red AC (ARAC) by Ochrobactrum anthropi HAR08, isolated from textile dye contaminated soil.

A dye degrading bacterial strain HAR08 was isolated from soil contaminated with textile dyes. This isolate was identified as Ochrobactrum anthropi on the basis of biochemical characteristics and phylogenetic analysis based on 16s rRNA gene sequencing. The strain HAR08 was able to decolorize the azo dye Allura Red AC (ARAC) up to 95% in the nutrient medium within 24 h with the dye concentrations of 10 g l-1and was confirmed by spectrophotometry. A remarkable reduction in COD (95.7% after 24 h) of the dye ARAC was observed after the action of the isolated strain OchrobactrumanthropiHAR08. Slight decrease in decolorizing ability (91%) of the strain was observed when the nutrient medium was half diluted, but in the presence of external co-substrate, the strain showed enhancement in the ability to decolorize the dye (99%). The cell-free extract showed the remarkable decolorization of the dye (92.1%) proving the involvement of intracellular enzymes for decolorizing the dye. The degradation of the ARAC was confirmed by FTIR and GCMS techniques and was found to be completely mineralized. Phytotoxicity analysis was carried out on seeds of Sorghum bicolor plant and the dye degradation product was found to be non-phytotoxic. The isolate HAR08 was able to tolerate, decolorize and degrade the azo dye ARAC at high concentrations (10 g L-1) within 24 h. This biodegradation and detoxification potential of the bacterial strain HAR08 makes it better candidate in treatment of dye effluents.