Removing the precipitated asphaltenes from the facilities of oil industry is of vital importance. In this study, the possibility of the precipitated asphaltene biodegradation from a crude oil sample using indigenous bacterial species isolated from different oil-contaminated samples of a Middle East oilfield has been investigated. On the basis of the achieved designed experiments results using response surface methodology, identified bacteria were cultured in the flasks on pure and consortium. Three levels of temperatures, salinity, pH, and initial asphaltene concentration were considered as growth medium parameters, and the flasks were incubated for 60 days. The CHNS and FT-IR analysis have been performed to evaluate the asphaltene elemental and structural alteration after the biodegradation process. The validity of some kinetic models to predict the behavior of the microbial systems was studied. The maximum asphaltene biodegradation was 41.95% and carbon, hydrogen, and nitrogen content of treated samples decreased significantly during the bacterial activity.
