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.

Commercial, industrial, and military activity, largely in the 19th and 20th centuries, have led to  environmental pollution that can threaten human health and ecosystem function, liquid gas petroleum (LPG) products are the major sources of energy for industry and daily life that cause environmental contamination during various stages of production, transportation, refining and use. Screening of bacterial isolate by using clear zone techniques and biomass and optical density. Results revealed that isolate Burkholdaria cepatia showed a high ability for hydrocarbons biodegradation and this isolate identified depending on morphological cultural, gram stain, microscopic features, biochemical tests, and VITEK2 compact.   In this study, Burkholdaria cepatia had been examined to degrade hydrocarbons in soil. Such strain which is isolated from petroleum hydrocarbon contaminated soil has the ability to utilize a variety of hydrocarbons substrates. Optimal conditions that include (time, temperature & pH) were studied for hydrocarbons biodegradation by Burkholdaria cepatia, results showed with high growth and hydrocarbons biodegredation. Biodegradation Experiments were carried out in lab scale and the growth of microorganisms was investigated directly and indirectly. Results showed an extent of biodegradation more than 80% can be achieved within 10 days using.