Reduction in the Sulfur Content of Fossil Fuels by Cunninghamella elegans (UCP 0596) to Dibenzothiophene Compound

Abstract

Biodesulfurization (BDS) is one of the most promising technologies used together with traditional hydrodesulfurization (HDS) to reduce the sulfur content of fossil fuels. In this research study, a strain of Cunninghamella elegans (UCP 596) was isolated from mangrove sediments to metabolize an organosulfur dibenzothiophene (DBT) compound in the concentrations of 0.5 and 1 mM and transform to DBT sulfone (DBT-5-dioxide), followed by dibenzothiophene 5,5-dioxide and 2-hydroxybiphenyl metabolites, thus suggesting the use of the "4S" metabolic pathway. The fungus also degraded the DBT completely in the first 24 h of growth on a 2.0 mM DBT concentration by angular deoxygenation, which suggests that a new second metabolic pathway was used. The DBT was consumed as the carbon source, and the sulfur was removed in the form of sulfite ion. A new product, benzoic acid, was formed at the end of the catabolism of DBT by C. elegans using an angular route.

Optimizing the Metabolic Performance of Mixed Bacterial Culture Towards Dibenzothiophene Desulfurization under the Effect of Varying Nutrient and Environmental Factors

“…The bacterium Pseudomonas putida CECT 5279 also showed a decreased rate of desulfurization when the concentration of DBT was increased or decreased than the optimal level. Patricia et al [30] have provided 0.5, 1.0, and 2.0 mM initial concentrations of DBT to the fungus Cunninghamella elegans UCP 0596. Although an effective degradation of DBT (about 100 % with…”