Document Type : Research Paper
Authors
1
Department of microbiology, Faculty of Veterinary Medicine, Ilam University, Ilam, Iran
2
Department of Microbiology, Faculty of Veterinary Sciences, Ilam University, Ilam, Iran
3
Ilam Higher Education Institute of Safir Danesh
Abstract
Natural gas is a critical energy resource, but sour gas, characterized by high hydrogen sulfide (H₂S) content, poses significant environmental and operational challenges, including corrosion, toxicity, and air pollution. Conventional desulfurization methods, such as hydrodesulfurization (HDS), are energy-intensive and environmentally taxing. Biodesulfurization (BDS) using sulfur-oxidizing bacteria (SOB) offers a sustainable alternative. This study, the first to characterize SOB from the Ilam Gas Refinery in Iran, aimed to isolate and identify SOB from soil samples to explore their potential for biodesulfurization and bioremediation. Soil samples were collected from various locations within the Ilam Gas Refinery, and 16 bacterial isolates were obtained using media enriched with sulfur compounds and sulfur-enriched media. The isolates were purified and characterized through Gram staining and molecular identification using 16S rRNA gene sequencing. Phylogenetic analysis was conducted to understand the evolutionary relationships among the isolated bacteria. The isolates were purified, characterized through Gram staining, 16S rRNA gene sequencing, and phylogenetic analysis. Sixteen bacterial isolates were cultivated, with 11 successfully identified through 16S rRNA gene sequencing. The identified species included Achromobacter xylosoxidans, Sphingomonas paucimobilis, Streptomyces babili, and Priestia megaterium. These species, particularly S. babili and P. megaterium, are less commonly associated with gas refinery environments, highlighting the novelty of this study. Statistical analyses confirmed a significant predominance of Gram-negative bacteria (p < 0.05). The study also identified the potential of these bacteria in the bioremediation process. The inability to amplify the soxB gene suggests alternative sulfur oxidation pathways, warranting further investigation. The findings provide a foundation for developing microbial-based solutions that are not only efficient but also efficient, cost-effective and environmentally sustainable.
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