Simultaneous Biosurfactant Production and Hydrocarbon Biodegradation by the Resident Aerobic Bacterial Flora of Oil Production Skimmer Pit at Elevated Temperature and Saline Conditions

Six aerobic thermo- and halotolerant bacterial isolates from an oil production skimmer pit were evaluated for their ability to produce biosurfactants and degrade petroleum hydrocarbons simultaneously under elevated temperature and saline conditions. Phylogenetic analysis using 16S rRNA sequencing revealed that the six bacterial isolates used in the study (SKP-1, SKP-2, SKP-3, SKP-4, SKP-5 and SKP-6) were most homologous to the gamma-proteobacteria Pseudomonas sp. VS-1, Pseudomonas aeruginosa strain S2QPS8, Serratia marcescens strain A4, Pseudomonas stutzeri, Pseudomonas stutzeri strain RA10 and Pseudomonas stutzeri strain BOD-3 respectively. Using previously sterilized skimmer pit sample as the sole nutrient, carbon and energy sources and at an elevated temperature of 45 0 C and salinity (chloride) level of 6012 mg L -1 , all the bacterial isolates in a mixed culture were able to grow, produce biosurfactants and degrade petroleum hydrocarbons simultaneously by removing about 92% of residual TPH in the skimmer pit within 2 weeks of exposure. This study suggests that in-situ bioremediation procedure using the resident aerobic bacterial flora of the skimmer pit that are thermotolerant and halotolerant can be developed to degrade the petroleum hydrocarbon contaminants in-situ. This bioremediation procedure can be a more attractive and cost effective option than the costly thermal treatment option that is currently in operation in the industry.