Isolation and purification of petroleum-decomposing bacteria from contaminated soils and identification the resulted compounds of degradation of such compounds

There are various methods to remove oil pollution from natural sources, which biological methods seem to be more appropriate methods due to their cheapness, sustainability and biodegradability. So, the aim of the present study was to isolate and identify the bacteria which able to degrade oil from contaminated soils to determine the optimal conditions for decomposition of these compounds in complementary studies. Soil sampling was performed from contaminated areas around the Tehran refinery and after isolating oil-degrading bacteria in a culture medium containing 2% kerosene (as the only carbon source), the ability of separated isolates to oil degradation were evaluated using FTIR and GC-MS. Finally, these isolates were identified using morphological, biochemical and molecular methods.Results and The results showed that, three oil decomposing isolates were able to reduce or eliminate the aromatic compounds from the oil. They decomposed oil complex alkanes into simpler alkanes. So in their culture medium, substances with amine and carboxyl functional groups (organic compounds) were observed. The identification of these three isolates showed that they belong to the species Nocardia sp, Bacillus subtilis and Acinetobacter baumannii. As conclusion, the use of this biological method can be a good alternative for physical and chemical ones. Isolation of native soil bacteria that have adapted with petroleum products in the soil can be helpful for bioremediation.