Bioremediation of actual soil samples with high levels of crude oil using a bacterial consortium isolated from two polluted sites: investigation of the survival of the bacteria

Abstract

In this study, actual soil samples, taken from Kharg Island, Iran, with high levels of total petroleum hydrocarbons (TPHs) were bioremediated by a bacterial consortium. The strains were: Pseudomonas sp., Stenotrophomonas sp., Achromobacter sp., Brevibacillus sp. and Staphylococcus sp., which were isolated from two highly polluted sites: Kharg Island and Kermanshah Oil Refinery. The bacteria were identified and confirmed by biochemical tests and the PCR assay. In order to isolate the bacteria, the enrichment method, in which crude oil (2%) was utilized as the sole source of carbon and energy, was used. The results showed that the adapted bacterial consortium could degrade nearly 60% of the pollution. Also, it was found that after 100 days of bioremediation only Brevibacillus sp. could survive in the environment.