Biodegradation of Jet Fuel by Three Gram Negative Bacilli Isolated from Kerosene Contaminated Soil

Petroleum hydrocarbon contamination is a major global prevalent issue in the petroleum sector. This research focuses on evaluating biodegradation of three Gram-negative bacilli, isolated from cowpea planted soil, contaminated with kerosene. The Gram negative bacilli strains have been characterized and identified, using MicrobactTM ID24E systems for the identification of Enterobacteriaceae and common Miscellaneous Gram-Negative Bacilli (MGNB). The identified organisms include Aeromonas hydrophila, Vibrio parahaemolyticus, and Actinobacillus sp. with the biodegradation indices, monitored for the evaluation of their degrading abilities, being Optical density at 600 nm (OD600nm), pH, and emulsification stability. The chemical profile of single cultures and mixed cultures (consortia) on the jet fuel hydrocarbon has been determined by means of Gas Chromatography Mass Spectrometry (GC-MS), the results of which indicate that all the isolates have undergone above 70% reduction of the hydrocarbon substrates in terms of residual compounds. There has been 48 hydrocarbon compounds in the undegraded jet fuel which, following degradation process, decrease to 5, 13, 7, 10, 6, 9, and 10 compounds for Aeromonas hydrophila, Vibrio parahaemolyticus, Actinobacillus sp., Aeromonas hydrophila and Vibrio parahaemolyticus, Aeromonas hydrophila and Actinobacillus sp., Vibrio parahaemolyticus and Actinobacillus sp., Aeromonas hydrophila, Vibrio parahaemolyticus, and Actinobacillus sp., respectively. The degradation efficiency of the isolates have been relatively high and comparable to the control. Results from this study indicate that all the strains, especially the consortia, are potential candidates for remediating the problem of hydrocarbon contamination in the environment.