Isolation and phylogenetic analysis of indigenous oil-degrading bacteria from soil of Karoon area in Ahvaz

Bioremediation is the promising technology for the treatment of the contaminated sites since it is cost-effective and will lead to complete mineralization. This study was aimed to isolation and phylogenetic identification of indigenous oil-degrading bacteria from soil of Karoon area in Ahvaz.
The crude oil contaminated soil of Karoon area in Ahvaz was sampled accidentally and under sterile condition. The amount of absorbable phosphorus was determined using Olson method and also, carbon, hydrogen and nitrogen by CHN meter device. Mineral salt medium containing 2% crude oil was used for isolation of oil eating bacteria. Following sieving the soil samples, the total carbon content of the soils were analysed by gas chromatography. Biochemical tests and PCR method were used to identify the dominant bacteria.
In this study, 44 bacterial strains were isolated, among them 20 isolates in the first and one in the second screening methods were selected, which was nominated as S31.This strain belonged to Bacillus licheniformis. The growth of the selected isolate in the media with 2% crude oil was better than the standard strain and remediated 84% of the crude oil in 30 days incubation time at about 30o C.
The selected Bacillus could use 2% of crude oil as source of carbon and energy and we suggest further studies on this bacterium in bacterial consortia.