THE INVESTIGATION OF OIL DEGRADING CAPACITY OF BACTERIAL STRAINS ISOLATED FROM DIFFERENT ENVIRONMENTS IN TURKEY

Abstract

The analyses were carried out with the aim of determining the oil-degradation capacity of bacterial strains isolated from different locations in Turkey. A total of 103 wild bacterial strains isolated from different marine environments and from the soil surrounding petroleum refineries in the city of Batman, Turkey, were screened with respect to their MIC (Minimum Inhibition Concentration) in Batman crude oil. Five bacterial isolates and their mixed consortiums were selected and investigated to detect their degradation capabilities with respect to different parameters including hemolytic activities, pH values, the emulsification index and the oil layers' thickness during the 30 days of incubation. The growth profiles of the isolates in the media with and without crude oil were also studied. In order to better understand the oil degradation capacity of the isolates, their performance was compared with the standard oil degrading bacterial strains, Alcanivorax borkumensis and Vibrio cyclitrophicus. The degradation activities of all of the five strains (Escherichia coli MDK04, Bacillus subtilis BR02, Vibrio fluvialis MD03, Staphylococcus haemolyticus GA01, and Pseudomonas aeruginosa BR03) and their consortiums were better than the reference strains. The experimental results indicated that the isolates from this study were efficient in using crude oil as the sole source of carbon and energy. We suggest that natural bacteria isolates from oil-polluted areas are likely to be as suitable candidates as standard oil-degrading bacterial strains for the purpose of cleaning up oil spills. This study significantly contributed to our knowledge about the possibility of the use of natural bacterial isolates in situ bioremediation of crude oil spills.