Biodegradation Potentials of Hydrocarbon Degraders from Waste-lubricating Oil-spilled Soils in Ebonyi State, Nigeria

The potential of bacterial isolates as hydrocarbon degraders was investigated. A total of 27 bacterial isolates were able to grow on mineral salt medium by enrichment procedure. The result of the screening tests of the isolates for hydrocarbon degradation showed different degree of degradation in mineral salt medium using spent oil as sole source of carbon were characterized and identified using standard methods. The bacterial isolates identified as Bacillus, Pseudomonas and Corynebacterium species showed different growth as measured by the optical density, total viable count, and different range of pH values throughout the period of incubation. Hydrocarbon degradation was demonstrated by gas chromatography and the result showed that Corynebacterium sp. has the highest ability to degrade spent motor oil (71.85%) followed by Pseudomonas sp. (63.46%), while Bacillus sp. (2.76%) found it difficult to degrade the hydrocarbon. In addition, emulsification test was carried out for the three organisms, and the results showed that Corynebacterium sp. has the highest emulsification ability at 1% spent oil. In conclusion, this study suggests the potential use of the isolate for bioremediation of contaminated environments. ？ 2011 Friends Science Publishers