DefinePK

Abstract

Background:   The extreme toxicity of petroleum products to human and environmental health, particularly when linked to large-scale unintentional spills, has made them one of the most serious and current environmental pollution issue. Petroleum products are a complex mixture of hydrocarbons. Methods:  Oil-contaminated soil samples were gathered and utilized to isolate hydrocarbon-degrading bacterial isolates. The bacterial isolates possessing bioremediation capabilities were identified using phenotypic determination and biochemical properties. The Optimal conditions including incubation period, temperature, different pH values and different carbon sources were studied for bioremediation of crude oil by bacterial isolates. Result:  In Wasit province of Iraq , Pseudomonas putida, P. fluorescens,  and  P. aeruginosa  isolated from soil samples tainted with petroleum hydrocarbons.  Pseudomonas putida  have more ability for bioremediation of crude oil (68%) compared to  P. aeruginosa  and  P. fluorescens  (47%, 58%) respectively. The results of optical density (600nm), biomass and (E24%) index for  Pseudomonas putida  were (1.080, 1.98 and 60%) respectively. The Optimal conditions (incubation period, temperature, different pH values and different carbon sources) were studied for bioremediation of crude oil by  Pseudomonas putida  by using liquid BHM supplemented with 1% crude oil. The result of this study showed that the incubation period of 9 days was the optimum for  bioremediation of hydrocarbons which was 88.33%. The optimum temperature and pH were 35 °C and 7 respectively. The carbon source (glucose and fructose) was optimal for hydrocarbon bioremediation. Conclusion:  This bacterial isolate  Pseudomonas putida  can be use in petroleum hydrocarbon bioremediation process. Keywords:  Pseudomonas putida ; Bioremediation; Optical density