BIODEGRADATION OF 2-CHLOROPHENOL BY BACILLUS SUBTILIS ISOLATED FROM INDUSTRIAL SLUDGE

A bacterial culture isolated from effluents of paper and wood industry was found to assimilate 2-chlorophenol (2-CP). The isolated bacterium was identified as Bacillus subtilis based on its morphological, biochemical and rDNA analysis. The bacterium degraded about 95% of 2-CP in 60 days along with production of an exopolysaccharide which probably provides protection from substrate toxicity and enhances its bioavailability. The thin layer chromatography (TLC) and Gas Chromatography-Mass spectroscopy (GC-MS) analysis of the extracts obtained from B. subtilis spent medium indicated the presence of phenol. The enzyme analysis of the cell free extracts showed the presence of chlorophenol dehalogenase (CD) and chlorophenol-NADPH-oxido-reductase (CNOR) with specific activities of 0.51 and 1.97 respectively suggesting dechlorination as an initial step during 2-CP catabolism. The GC-MS data further showed that the product is metabolized via ortho cleavage pathway. The study thus highlights the important roles bacteria in the decontamination of environmental pollutants from the polluted sites. KEY WORDS 2-Chlorophenol Dechlorination rDNA gene analysis GC-MS Received on : 11.12.2010