Desulfurization of Dibenzothiophene by Klebsiella oxytoca Isolated from Oil-Contaminated Soils in Southern Ahvaz

The crude oil of various oil reservoirs have up to 7% sulfur and between 50 - 95 % of the sulfur are in the form of different thiophenes. The Combustion of organosulfur compounds produces sulfur oxides that are the main cause of acidic rain and environmental pollution. The current method for desulfurization is hydrodesulfurization which is too expensive and sulfur does not get completely isolated, therefore, the researchers have focused on biodesulfurization method. Dibenzothiophene (DBT) has been used as a molecule model for validation of microorganisms’ ability in desulfurization. There is no report about chemolithoautotrophic bacteria that desulfurizes the crude oil. The isolated ISA4 bacterium which is used in this study doesn’t break carbon – carbon bond structure and only remove the sulfur from the skeleton of DBT. From the industrial view, this bacterium does not need organic materials as energy and carbon source for desulfurizing the crude oil. ISA4 Bacterium with 100% query and 99% homology is similar to Klebsiella oxytoca.