Rapid biodegradation and decolorization of Direct Orange 39 (Orange TGLL) by an isolated bacterium Pseudomonas aeruginosa strain BCH

Abstract

A newly isolated novel bacterium from sediments contaminated with dyestuff was identified as Pseudomonas aeruginosa strain BCH by 16S rRNA gene sequence analysis. The bacterium was extraordinarily active and operative over a wide rage of temperature (10-60 degrees C) and salinity (5-6%), for decolorization of Direct Orange 39 (Orange TGLL) at optimum pH 7. This strain was capable of decolorizing Direct Orange 39; 50 mg l(-1) within 45 +/- 5 min, with 93.06% decolorization, while maximally it could decolorize 1.5 g l(-1) of dye within 48 h with 60% decolorization. Analytical studies as, UV-Vis spectroscopy, FTIR, HPLC were employed to confirm the biodegradation of dye and formation of new metabolites. Induction in the activities of lignin peroxidases, DCIP reductase as well as tyrosinase was observed, indicating the significant role of these enzymes in biodegradation of Direct Orange 39. Toxicity studies with Phaseolus mungo and Triticum aestivum revealed the non-toxic nature of degraded metabolites.