Biodesulfurization of dibenzothiophene by microorganisms isolated from oil-contaminated soils

Biological desulfurization by microorganis msisasuit able method to remove sulfur containing compounds from fossil fuels.The aim of the present research was to introduce indigenous microorganisms with the ability to biologically remove of sulfur.In order to isolating native microorganisms, oil contaminated soil samples taken from Abadan oil refinery were transferred to the microbiology laboratory.Enrichment of oil-contaminated soil samples was performed during 4 subcultivations in BSM medium with 0.5 mM DBT as the only source of sulfur during which 20 bacterial isolates were obtained.Superior isolates were selected based on growth rate and turbidity caused by the consumption of DBT.In order to investigate the possible metabolic pathway of desulfurization in isolates, the most common metabolic pathway of desulfurization, i.e. 4S pathway, was tracked through the Gibbs assay, and the production of blue color could confirm the existence of this pathway in microorganisms.GC-MS method was used to check the amount of dibenzothiophene reduction.Isolates BDS9, BDS18 and BDS37 were able to remove 95.7%, 95.5% and 86.5% of DBT over a period of 72 hours, respectively.