دراسة التحلل الحيوي للنفط الخام بواسطة عزلات بكتيرية معزولة من ميناء الحريقة، طبرق، ليبيا

الملخص EN

Research in the field of remediation of oil pollution has pointed to the important role that microorganisms can play in redressing that pollution, and consequently environmental remediation, as they can utilize petroleum hydrocarbons as a sole source of carbon.

this work aimed at isolating oil-degrading bacteria from EL-Harika port in Tobruk city.

twenty-two bacterial isolates from EL-Harika Port were grown on a liquid medium contained crude oil as a sole carbon source.

the isolates were then grown in five different oil concentrations which were (1 %, 5 %, 10 %, 25 %, and 50 %).

Some of the isolates (WiCb, W2Aa, W2Ab, W2Ca, W3Ba, W3C, and W4Aa) exhibited differential abilities of growth up to 50 % oil.

these selected bacterial isolates (W2Aa, W2Ca, W3Ba, W3C, and W4Aa) were identified using the 16S rRNA methodology in the European Nucleotide as ; Marinobacter hydrocarbonoc lasticus, Vibrio hepatarius, Vibrio alginolyticus, Vibrio parahaemolyticus, and Eubacteriumcombesii, respectively.

the bacterial growth in 1 % crude oil calculated as optical density (OD) measurement indicate the ability of all isolates for growth in crude oil for a period of 7 days, and continuation of growth for more than 21 days.

in another investigation on bacterial growth in crude oil, a gas chromatographic analysis was conducted on the growth of five isolates which indicated that the highest rate of degradation (95.23 %) was recorded in Vibrio alginolyticus isolate (W3Ba), and the lowest rate (47.61%) was recorded by Marinobacter hydrocarbonoclasticus and Vibrio parahaemolyticus.

from the results obtained in this study, it can be concluded that the local bacterial isolates Marinobacter hydrocarbonoclasticus, Vibrio hepatarius, Vibrio alginolyticus, Vibrio parahaemolyticus, and Eubacteriumcombesii have a good capacity to degrade crude oil, and thus they can be used in the bioremediation of crude oil pollution.