Isolation of Polycyclic Aromatic Hydrocarbon Degrading Bacterial Strains Isolated from Indigenous Microbial Communities of Petroleum Contaminated Soils

Soil and sludge samples polluted with petroleum waste from Cairo Oil Refining Company Mostorod, Qalyubia, Egypt for more than 41 years were used for isolation of indigenous microbial communities. These communities were grown on seven polycyclic aromatic hydrocarbon compounds (naphthalene- (Naph.), phenanthrene (Phen.), anthracene (Anth.), fluorancene (Flu.), acenaphthene (Acen.), pyrene (Pyr.) and benzo-a- anthracene (B-a-Anth.)) as a sole carbon and energy source. The growth of the seven different bacterial communities on the seven different PAHs had been investigated by recording their growth (O.D) and secretion of extracellular protein at zero time (initial) and after 7, 15, 21 and 28 days incubation. The growth of community these seven communities after 28 days incubation revealed an increase in bacterial count ranging from 0.8-1.0 ; 0.9-1.3 ; 0.9- 1.2 ;0.7 -1.0 ; 0.9-1.2 ; 0.9-1.3 and 0.6-1.2 log cycles on Naph. Phen. Anth. Flu. Acen. Pyr. And B-a- Anth. respectively. The highest total bacterial count at zero time (initial) was 1.6 x 10 CFU/ml for community (4), 7