Degradation of kerosene hydrocarbon by indigenous diazotropic bacteria isolated from crude oil contaminated soil

Hydrocarbon contamination significantly increases supply of carbon, but the availability of nitrogen and phosphorus generally become the growth limiting factors for indigenous oil degraders. This nitrogen imbalance selectively favors the development of the soil asymbiotic dinitrogen fixing microorganisms. The present study was undertaken to isolate such diazotrophic bacteria capable of degrading petroleum hydrocarbons. Two bacterial strains were isolated, and identified by using their 16SrDNA as Achromobacter sp. and Arthrobacter sp . Both the isolates could degrade almost all major components of kerosene hydrocarbon within 60 days. Hydrocarbon degradation by the isolates was studied under Gas chromatography-Mass spectroscopy (GC-MS) and the nitrogenase activity of the isolates was measured by Acetylene Reduction Assay. Results of the present investigation revealed the potentiality of free living indigenous nitrogen fixing bacteria to degrade petroleum hydrocarbon and thereby contribute to bioremediation and bio-fertilization of crude oil contaminated soil.