Petroleum is one of the most important substances consumed by man at present times, a major energy source in this century, petroleum oils can cause environmental pollution during various stages of production, transportation, refining and use, petroleum hydrocarbons pollutions ranging from soil, ground water to marine environment, become an inevitable problem in the modern life, current study focused on bioremediation process of hydrocarbons contaminants that remaining in the bottom of gas cylinders and discharged to the soil. Twenty-four bacterial isolates were isolated from contaminated soils all of them gram negative bacteria, bacterial isolates screening to investigate the ability of biodegradation of hydrocarbons, these isolates inoculated with modified mineral salt media containing 1% hydrocarbons for five days in shaking incubator 150 rpm at 30oC. Then measured optical density by a spectrophotometer (UV–9200) at waves length 540nm, biomass, where three isolates appeared highest ability to growth than others isolates. These three bacterial isolates were diagnosed by morphological features, gram stain, microscopically examination, biochemical tests, as well as by using VITEK 2 Compact device. One of three isolates was selected and result of identification of this bacterium showed that belonged to Serretia ficaria.
