Biodegradation of Petroleum Tar by Pseudomonas Spp. From Oil Field of Assam,India

ABSTRACT

Petroleum tar produced during the processing of crude oil is one of the earth's major pollutants. The potential of certain soil bacteria in the biodegradation of petroleum tar was assessed to develop an active indigenous bacterial consortium for bioremediation of petroleum tar–polluted sites of Assam, India. In vitro enrichment cultures of five Pseudomonas spp. were found to metabolize petroleum tar. The Fourier transform infrared (FTIR) analyses of the enrichment cultures revealed the presence of the functional groups, viz., –OH, –CHO, C?O, and –COOH, which provided evidence for the biodegradation of petroleum tar. Further, gas chromatography–flame ionization detection (GC-FID) analyses revealed complete degradation of low-molecular-weight hydrocarbons, and the subsequent appearance of some additional peaks reflected the formation of intermediate metabolites during the degradation of petroleum tar. A mixed culture with 0.1% Tween 80 as a surfactant exhibited almost complete degradation in contrast to the degradation by the mixed culture without Tween 80. This confirmed the effect of a surfactant for acceleration of the biodegradation process of petroleum tar.