Phylogeny and polycyclic aromatic hydrocarbons degradation potential of bacteria isolated from crude oil-contaminated soil in Diyarbakir, in the southeast of Turkey

Abstract

In the present study, four indigenous bacteria designed as OACR6-OACR9 capable of degrading Polycyclic Aromatic Hydrocarbons (PAHs) were isolated from oil-contaminated soils in Diyarbakir city, in Turkey. 16S rRNA gene analysis revealed that strain OACR6 indicated 99.78% homology to Bacillus megaterium NBRC 15308 = ATCC 14581. OACR7, OACR8 and OACR9 strains were found to be members of the Sphingobacterium genus according to genetic analysis. It was observed that the OACR7 and OACR8 strains were 96.63% and 96.94% similar to Sphingobacterium multivorum strain IAM 14316, respectively. On the other hand, strain OACR9 indicated 96.79% homology to Sphingobacterium siyangense strain SY1 16S. GC-MS analyzing revealed that strain OACR6 was able to degrade 68.7% of fluorene and 69.8% of phenanthrene compared to the controls, strain OACR7 was able to degrade 67.5% of fluorene and 65.9% of phenanthrene, strain OACR8 was able to degrade 74.4% of fluorene and 76.4% of phenanthrene and strain OACR9 was found to be able to degrade 67.9% of fluorene and 69.8% of phenanthrene. The findings of this study indicate that the strains investigated have bioremediation potential at oil-contaminated sites and to our knowledge, this is the first study on the biodegradation of PAHs in the oil-contaminated areas in Diyarbakir.