Isolation and Identification of Sulfur Degrading Bacteria in the Sludge from Tehran Refinery Wastewater Treatment

Identification of sulfur-degrading microorganisms is a major step in microbial desulfurization of organic compounds, especially oil. Microbial desulphurization is ecologically safe and economically justifiable; hence, the importance of knowledge on the identification, isolation, and adaptation of microorganisms from operational, economic, and environmental viewpoints. The objective of this descriptive‒applied research was to identify and isolate sulfur-degrading bacteria in the sludge from Tehran refinery wastewater treatment plant. For this purpose, 120 samples (10 samples per month over a 12‒month period) were collected from different locations and elevations of the sedimentation basin. The samples were then stirred and homogenized before they were transferred to the laboratory where they were cultured on specific and differential media to allow the microorganisms to grow. Finally, tests were performed and the following bacteria were identified in the samples: Brevundiomonas vesicularis, Acinetobacter spp, Clostridium spp, Alcaligenes spp, E.coli, Bacillus spp, Klebsiella spp, Acromobacter spp, and Desulfovibrio spp. Results indicate that all the bacteria identified in the samples used sulfur as their only source of energy. Another important contribution of this study is that Brevundiomonas vesicularis is for the first time identified in this study as a sulfur-degrading one.