Biodegradation of Some Aromatic Hydrocarbons (Toluene and Xylene) by a Bacterial Strain Isolated from Petroleum Contaminated Site in Chennai

Pseudomonas putida strain was isolated from petroleum polluted soil in Chennai by enrichment culture method to evaluate the biodegradation potential of toluene and xylene. The isolated bacterial strain in this study could grow in Bushnell Haas medium and mineral salt medium containing 1% each of toluene and xylene as the sole source of carbon and energy. The plasmid DNA was isolated by alkali lysis method and separated by agarose gel electrophoresis. The molecular weight of the plasmid was determined as 106Kb. Liquid culture studies were performed to determine the effect of pH and temperature on TX biodegradation. The isolated strain showed maximum degradation at 30° C and at pH 7.0. The kinetics of TX biodegradation was investigated at different time intervals (2.5 Hrs. - 12.5 Hrs.) and the biodegradation rate was maximum between 5 Hrs. and 12.5 Hrs. The conclusions that can be drawn from this study indicate that the microorganism present in this study could contribute significantly to bioremediation of TX pollution.