Isolation, screening and characterization of crude oil degrading bacteria isolated from Al- Dora refinery wastewater treatment plant

Fifty two wastewater samples from wastewater treatment plant of Al-Dora refinery were collected at period from February 2012 to January 2013. 154 bacterial isolates were isolated from wastewater samples using liquid and solid BH medium with 1% crude oil as a carbon source. Primary screen were done using solid BHmedium with 1% crude oil, the bacterial isolates were inoculated and incubated at 30 ̊C for five days. Results shown that 45 isolates were appeared the highest growth ability. Secondary screen were done for bacterial isolates selected from primary screen using clear zone and redox indicator ( DCPIP) techniques . Results shown that B.T.23, B.T.27 and A.T.90 isolates have the best ability for crude oil degradation .The three isolates were characterized based on morphological , cultural and biochemical tests , subsequently was identified and designated as Pseudomonas aeruginosa , Bacillus cereusand Bacillus subtilis respectively.