The Efficiency of Acinetobacter Radioresistens Strain KA2 Isolated From Oily Sludge for Degrading of Crude Oil ‎

 The widespread application of crude oil and its products has caused numerous environmental pollutions. This study aimed to isolate, identify, and determine a bacterial strain’s potential of oil degradation isolated form oily sludge. 

After preparing the oily sludge in the sterile containers and cultivating in Bushnell-Haas medium, 24 distinct bacterial colonies were obtained. After performing biochemical and molecular tests, the “Acinetobacter radioresistens strain KA2” with the highest growth rate and crude oil degradation was selected. Then, degradation of various concentrations of crude oil at different PHs (5, 6, 7, 8 and 9), bacterial adherence to hydrocarbons and emulsification index of the selected strain were measured. Total petroleum hydrocarbons were determined by gas chromatography. 

 This study has been approved by the Research Ethics Committee of Islamic Azad University of Kermanshah Branch (code: 19250587962001 ).

 The results indicated that the removal efficiency of crude oil at concentrations of 1, 2, 3, 4, and 5% were 65.24, 76.14, 53.81, 31.84, and 25.21%, respectively. Crude oil removal at pH values of 5, 6, 7, 8, and 9 was 42.4, 69.16, 65.24, 59.41 and 48.24%, respectively. Bacterial adherence to hydrocarbons and emulsification index of the isolated strain were calculated to be 13.69 and 59.14%. 

 The isolated bacterium is an efficient strain in treating the crude oil and petroleum compounds.