Deep-desulfurization of dibenzothiophene and its derivatives present in diesel oil by a newly isolated bacterium Achromobacter sp. to reduce the environmental pollution from fossil fuel combustion

作者：Bordoloi Naba K; Rai Sudhir K; Chaudhuri Mihir K^*; Mukherjee Ashis K

来源：Fuel Processing Technology, 2014, 119: 236-244.

DOI：10.1016/j.fuproc.2013.10.014

• Deep-desulfurization
• Achromobacter sp.
• Fossil fuel processing
• Response surface method
• Diesel oil

Thiophenic compounds viz. dibenzothiophene (DBT) and its derivatives present in fossil fuels contribute significantly to air pollution. Here we report for the first time the efficacy of a strain of Achromobacter sp., isolated from a contaminated petroleum-oil soil sample, at efficiently cleaving carbon-sulfur (C-S) bonds in DBT under mesophilic growth conditions. This bacterium utilized DBT and its derivative viz. 4-methyl DBT as the sole source of sulfur and degraded them to 2-hydroxybiphenyl (2-HBP). The 2-HBP was finally converted to 2-methoxybiphenyl (2-MBP) by methylation at the hydroxyl group of 2-HBP suggesting that this bacterium followed sulfur-specific pathway (4S pathway) for deep-desulfurization. Further, 2-MBP is much less pollutant than DBT and therefore, it reduces the environmental pollution from fossil fuel combustion. Gas chromatography and X-ray fluorescence analyses revealed that the resting cells of Achromobacter sp. reduced 7.1% of the total sulfur content of diesel oil, obtained typically by treating 5 mL of diesel oil with 14 g of dry cell, without compromising the quality of diesel oil. For the industrial application, DBT desulfurization was optimized by using response surface methodology. Our study demonstrates that Achromobacter sp. is a potential candidate for biodesulfurization of diesel oil with anticipated application as an eco-friendly biodesulfurizing agent.

• 出版日期2014-3