Enzymatic desulfurization of dibenzothiophene by a cell-free system of Rhodococcus erythropolis D-1

Ohshiro, Takashi

doi:10.1016/0378-1097(94)90526-6

Cited by 9 publications

(10 citation statements)

References 11 publications

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“…del Olmo et al 2005a;Ohshiro and Izumi 1999;Kilbane and Jackowski 1992;Honda et al 1998;Guchhait et al 2005). Concerning to the operation modes, aerobic BDS conversion can be carried out by growing cells Honda et al 1998;Guchhait et al 2005), free cell extracts (Ohshiro et al 1994) and also resting cells (Ohshiro et al 1999;Gallagher et al 1993;Oldfield et al 1997;Maghsoudi et al 2001;Jia et al 2006;Luo et al 2002). The highest DBT conversion levels reported in literature has been achieved with resting cells (Ohshiro et al 1996;Konishi et al 1997).…”

Section: Introductionmentioning

confidence: 89%

Description of by-product inhibiton effects on biodesulfurization of dibenzothiophene in biphasic media

et al. 2007

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As several authors have reported previously, the Biodesulfurization of hydrodesulfurization recalcitrants, such as dibenzothiophene, is not yet commercially viable because mass transfer limitations and feedback inhibition effects are produced during the conversion. This work has been focused to investigate the inhibition process in aqueous and oil-water systems with two different aerobic biocatalysts types, Rhodococcus erythropolis IGTS8 and Pseudomonas putida CECT 5279. The results obtained have proven that global DBT desulfurization process using CECT 5279 was not clearly deactivated due to final product accumulation, under the experimental conditions assayed. Consistently, the desulfurization pattern has been described with the Michaelis-Menten equation, determining the kinetic parameters. On other hand, the assays have shown that important mass transfer limitations produced the decrease of the yields obtained with this Gram(-) strain in biphasic media. With strain IGTS8 it was observed lower mass transfer problems, but contrary the reaction was severely affected by the final product accumulation, in both aqueous and biphasic systems. Therefore it has been proposed an enzymatic kinetic model with competitive inhibition to describe the BDS evolution pattern when this Gram(+) strain was used.

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Section: Introductionmentioning

confidence: 89%

Description of by-product inhibiton effects on biodesulfurization of dibenzothiophene in biphasic media

et al. 2007

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“…It has been reported that some bacteria utilize DBT as a sole source of sulfur without breaking its carbon-carbon backbone. This sulfur-specific pathway has been extensively studied by using two Rhodococcus strains, Rhodococcus erythropolis IGTS8 (7,11,13) and R. erythropolis D-1 (10,19,20). The genes encoding enzymes involved in this pathway have been cloned and sequenced in R. erythropolis IGTS8 (2,3,25) and the thermophilic desulfurizing bacterium Paenibacillus sp.…”

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confidence: 99%

Purification, Characterization, and Overexpression of Flavin Reductase Involved in Dibenzothiophene Desulfurization by Rhodococcus erythropolis D-1

Matsubara

Ohshiro

Nishina

et al. 2001

Appl Environ Microbiol

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The dibenzothiophene (DBT)-desulfurizing bacterium, Rhodococcus erythropolis D-1, removes sulfur from DBT to form 2-hydroxybiphenyl using four enzymes, DszC, DszA, DszB, and flavin reductase. In this study, we purified and characterized the flavin reductase from R. erythropolis D-1 grown in a medium containing DBT as the sole source of sulfur. It is conceivable that the enzyme is essential for two monooxygenase (DszC and DszA) reactions in vivo. The purified flavin reductase contains no chromogenic cofactors and was found to have a molecular mass of 86 kDa and four identical 22-kDa subunits. The enzyme catalyzed NADH-dependent reduction of flavin mononucleotide (FMN), and the K m values for NADH and FMN were 208 and 10.8 M, respectively. Flavin adenine dinucleotide was a poor substrate, and NADPH was inert. The enzyme did not catalyze reduction of any nitroaromatic compound. The optimal temperature and optimal pH for enzyme activity were 35°C and 6.0, respectively, and the enzyme retained 30% of its activity after heat treatment at 80°C for 30 min. The N-terminal amino acid sequence of the purified flavin reductase was identical to that of DszD of R. erythropolis IGTS8 (K. A. Gray, O. S. Pogrebinsky, G. T. Mrachko, L. Xi, D. J. Monticello, and C. H. Squires, Nat. Biotechnol. 14:1705-1709, 1996). The flavin reductase gene was amplified with primers designed by using dszD of R. erythropolis IGTS8, and the enzyme was overexpressed in Escherichia coli. The specific activity in crude extracts of the overexpressed strain was about 275-fold that of the wild-type strain.Organic sulfur compounds are found in fossil fuels, the combustion of which causes serious environmental problems, such as acid rain. At the refinery, hydrodesulfurization is currently performed to remove sulfur compounds from fossil fuels. This process is done at high temperatures and pressures by metal catalysis and is effective for removing inorganic sulfur and simple organic sulfur compounds. However, it is difficult to remove polycyclic sulfur compounds. As legislative limits on sulfur emissions have become tighter, the need to remove polycyclic sulfur compounds from fuel has become more pressing. Dibenzothiophene (DBT) is considered a model polycyclic sulfur compound contained in fossil fuels. It has been reported that some bacteria utilize DBT as a sole source of sulfur without breaking its carbon-carbon backbone. This sulfur-specific pathway has been extensively studied by using two Rhodococcus strains, Rhodococcus erythropolis IGTS8 (7, 11, 13) and R. erythropolis D-1 (10, 19, 20). The genes encoding enzymes involved in this pathway have been cloned and sequenced in R. erythropolis IGTS8 (2, 3, 25) and the thermophilic desulfurizing bacterium Paenibacillus sp. strain A11-2 (9). In this pathway, DBT is oxidized to DBT sulfone via DBT sulfoxide by DszC, DBT sulfone is converted to 2Ј-hydroxybiphenyl 2-sulfinic acid (HBPSi) by DszA, and HBPSi is desulfurized to 2-hydroxybiphenyl by DszB (Fig. 1). Flavin reductase is necessary for monooxygenase reac...

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“…The authors further reported that from 1992 until 2017, many strains of Rhodococcus sp followed the 4S pathway. These include, for example, R. erythropolis D-1 (Ohshiro, Hine, & Izumi,1994), R. erythropolis H-2 (Ohshiro et al,1994), and Rhodococcus sp. ECRD-1 (Grossman et al, 2001), R. globerulus DAQ3 (Yang et al, 2007), R. erythropolis DRA (Q.…”

Section: Aerobic Desulfurizing Bacteriamentioning

confidence: 99%

“…For example, Rhodococcus sp IGTS8 was utilized on dibenzothiophene as a sole sulfur source in coal and crude oil (Kilbane & Bielaga, 1990;Nekodzuka et al, 1997). Here, the isolated Rhodococcuc erythropolis D-1 has been shown to selectively remove sulfur by oxidizing dibenzothiophene (Ohshiro et al, 1994). A similar study reported that the R. erythropolis H-2 was capable of attacking the sulfur atoms in 3,4-benzo DBT, 2,8-dimethy DBT, and 4,6-dimethyl DBT (Ohshiro et al, 1996), while the Rhodococcus erythropolis SHT87 completely desulfurized DBT (Davoodi-Dehaghani et al, 2010).…”

Section: Model Compounds For Biodesulfurization Systemsmentioning

confidence: 99%

Biodesulfurization of Sour Crude Oil

Alkhalili¹,

Yahya²,

Abrahim³

et al. 2017

MAS

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Crude oil is one of the most important types of fossil fuel in the world. It is an economically important commodity that is massively used in many industrial activities. The poor quality of crude oil is related to high sulfur content, which translates to lower profit margins and negatively impacts air quality standards. Polyaromatic sulfur heterocycles (PASHs) that exist in crude oil requires an efficient reduction method to achieve significant desulfurization levels. Recently, biodesulfurization (BDS) is gaining greater attention attributed to its environmentally benign bioprocess; possible benefits of BDS include lower capital and processing costs. Studies have reported that BDS is urgently needed for desulfurization of recalcitrant organic sulfur relative to traditional approach, hydrodesulfurization (HDS). The establishment of commercial scale biorefining technology relies on major advancement with respect to less expensive and sufficient production of highly active and stable biocatalysts that can be adapted to intense conditions encountered in petroleum refineries. In this paper, a review on BDS processes for removing recalcitrant thoiphenic components from sour crude oil is conducted, covering the aim of most studies concerning desulfurizing bacteria, which enables a deep desulfurization of organosulfur compounds by 4S pathway, maintaining the caloric value of fuel.

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Enzymatic desulfurization of dibenzothiophene by a cell-free system of Rhodococcus erythropolis D-1

Cited by 9 publications

References 11 publications

Description of by-product inhibiton effects on biodesulfurization of dibenzothiophene in biphasic media

Description of by-product inhibiton effects on biodesulfurization of dibenzothiophene in biphasic media

Purification, Characterization, and Overexpression of Flavin Reductase Involved in Dibenzothiophene Desulfurization by Rhodococcus erythropolis D-1

Biodesulfurization of Sour Crude Oil

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