Optimization of Growth Parameters of Dibenzothiophene Desulfurizing Streptomyces Species Isolated from Oil Contaminated Sites

Fossil fuels on combustion release hazardous gases into the environment and sulfur dioxideis one among them. Sufur dioxide is released as result of oxidation of organosulfur compounds occurring in fossil fuels. Presently hydrodesulfurization process is employed to remove sulfur content from fuels which is not an effective method. An alternative process that employs microbes is biodesulfurization, an efficient method for the desulfurization of sulfur even from recalcitrant organosulfur compounds like dibenzothiophene which considered as model compound for biodesulfurization studies. In the present study, optimum growth parameters required for two dibenzothiophene desulfurizing Streptomyces species namely Streptomyces sp. VUR PPR 101 and Streptomyces sp. VUR PPR 102 isolated from oil contaminated sites were determined. Glucose was found to be the optimum carbon source for both the species. . The optimum nitrogen sources for Streptomyces sp. VUR PPR 101 and Streptomyces sp. VUR PPR 102 were yeast extract and potassium nitrate, respectively. Both the species had shown highest growth with methionine. The optimum temperature and pH for both the species were 30oC and 7.0, respectively. Finally, with optimum nutrient sources and optimum physical parameters, both the Streptomyces species showed enhanced growth at 1 % salt concentration.