Biodesulfurization of Dibenzothiophene and Its Derivatives through the Selective Cleavage of Carbon-Sulfur Bonds by a Moderately Thermophilic Bacterium Bacillus subtilis WU-S2B.

Abstract

Heterocyclic organosulfur compounds such as dibenzothiophene (DBT) in petroleum cannot be completely removed by hydrodesulfurization using chemical catalysts. A moderately thermophilic bacterium Bacillus subtilis WU-S2B, which could desulfurize DBT at 50 degrees C through the selective cleavage of carbon-sulfur (CS) bonds, was newly isolated. At 50 degrees C, growing cells of WU-S2B could degrade 0.54 mM DBT within 120 h to produce 2-hydroxybiphenyl, and the resting cells could also degrade 0.81 mM DBT within 12 h. The DBT-desulfurizing ability of WU-S2B is high over a wide temperature range from 30 to 50 degrees C, and highest at 50 degrees C for both the growing and resting cells, and this is an extremely advantageous property for the practical biodesulfurization. In addition, WU-S2B could also desulfurize DBT derivatives such as 2,8-dimethylDBT, 4,6-dimethylDBT and 3,4-benzoDBT. Therefore, B. subtilis WU-S2B is considered to have more beneficial properties than other desulfurizing bacteria such as Rhodococcus strains previously reported, particularly from the viewpoint of its capacity for thermophilic desulfurization through the CS bond cleavage.

Genotypic Characterization of Sulfur-Oxidative Desulfurizing Bacterial Strains Isolated from Mexican Refineries

“…On the other hand, some bacterial species have been isolated which can metabolize DBT via a sulfur-specific elimination pathway, the 4S pathway ( Fig. 1) [5][6][7][8][9][10][11][12][13]. Among these strains, the patented Rhodococcus erythropolis IGTS8 strain has been the most extensively studied one and it was the basis of the commercial process proposed by the North American Energy Biosystems Corporation [5].…”

Desulfurization of Crude Oil and Oil Products by Local Isolated Bacterial Strains

“…2012). Numerous genera of bacteria are known as good hydrocarbon degraders Rhodococcus, Bacillus, Pseudomonas, Mycobacterium, Klebsiella, Pseudomonas, Actinomycetes, Enterobacter and Acinetobacter (Izumi et al, 1994;Kirimura et al, 2000;Ishii et al, 2005;Al-Zahrani and Idris, 2010;Jamshid et al, 2010;Bhatia, Sharma, 2012;Buzanello et al, 2014); however, reports on the utilization of complex sulfur mixtures like crude oil by isolated microbial species are few. To obtain an efficient desulfurizing bacterial consortium and monocultures, knowledge of the diversity of the microbial community present in sites contaminated with crude oil, their metabolic features and capacity to desulfurize crude oil are of paramount importance.…”

“…Other, biodesulfurizing bacteria were isolated and identified P. stutzeri (Dinamarca et al, 2010), P. putida (Alcon et al, 2005), R. erythropolis (Ansari et al, 2009), Mycobacterium sp. (Chen, 2008, Bacillus subtilis (Kirimura et al, 2001;Ohshiro et al, 2005;Al-Bahry et al, 2016) and Klebsiella sp. 13T (Bhatia and Sharma, 2012).…”

“…Microorganisms, particularly Rhodococcus (Izumi et al, 1994), Bacillus (Kirimura et al, 2000;Buzanello et al, 2014), Pseudomonas (Al-Zahrani andIdris, 2010, Jamshid et al, 2010), Mycobacterium , Klebsiella (Bhatia, Sharma, 2012)species have been found to metabolize crude oil and oil products as well as DBT as a source of sulfur by cleaving the C-S bond of sulfur compound in crude oil products or DBT via a sulfur-specific pathway (4 S pathway) without affecting the carbon skeleton. Tong et al, (2005) reported that Rodococcus spp desulfurizing organic sulfur of diesel oil by resting cells.…”

“…Strains from the bacterial genus Rhodococcus were most often reported, such as R. erythropolis. In literature, a number of other microorganisms, particularly Rhodococcus (Izumi et al, 1994), Bacillus (Kirimura et al, 2000), Buzanello et al, 2014, Pseudomonas (Al-Zahrani and Idris, 2010, Jamshid et al, 2010, Mycobacterium , Klebsiella (Bhatia, Sharma. 2012), Arthrobacter (Seo et al, 2006) and Gordonia species have been found to metabolize crude oil and oil products as well as DBT as a source of sulfur by cleaving the C-S bond of sulfur compound in crude oil products or DBT via a sulfur-specific pathway (4S pathway) without affecting the carbon skeleton.…”