Identification of Microbial Products from Dibenzothiophene and Its Proposed Oxidation Pathway

Kodama, Koki; Umehara, Kazuyoshi; Shimizu, Katsumi; Nakatani, Shigeru; Minoda, Yasuji; Yamada, Kōichi

doi:10.1271/bbb1961.37.45

Cited by 81 publications

(19 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Culture samples (1 ml) were collected every 30 min and clarified by centrifugation at 10,000×g for 2 min. The absorbance of the supernatant was measured using an Ultrospec 3100 pro UV-visible spectrophotometer (GE Healthcare) at 472 and 390 nm, corresponding respectively to the absorption maxima of the DBT intermediate metabolite trans-4[2-(3-hydroxy)-thianaphthenyl]-2-oxo-3-butenoic acid (HTOB) and the dead-end product of DBT metabolism (3-hydroxy-2-formylbenzothiophene) (Bressler and Fedorak 2001;Foght and Westlake 1996;Kodama et al 1973) (Fig. 1).…”

Section: Phenanthrene Metabolite Effluxmentioning

confidence: 99%

“…Unfortunately, DBT is not commercially available in radiolabeled form, precluding conventional efflux assays (Bugg et al 2000), but its partially oxidized intermediates are highly colored (Kodama et al 1973), making it ideal for spectrophotometric analysis. Therefore, to further characterize the substrate range of EmhABC for aromatic metabolites, suspensions of WEP and WEN cells incubated with 5 mmol l −1 DBT were monitored for the accumulation of metabolites in the supernatant, specifically the intermediate HTOB (an analog of the phenanthrene open-ring metabolite) and the dead-end product 3-hydroxy-2-formyl-benzothiophene (Fig.…”

Section: Emhabc Activity Decreases the Mineralization And Transformatmentioning

confidence: 99%

See 1 more Smart Citation

The EmhABC efflux pump decreases the efficiency of phenanthrene biodegradation by Pseudomonas fluorescens strain LP6a

Adebusuyi

Smith

Gray

et al. 2012

Appl Microbiol Biotechnol

View full text Add to dashboard Cite

Pseudomonas fluorescens strain LP6a, designated here as strain WEN (wild-type PAH catabolism, efflux positive), utilizes the polycyclic aromatic hydrocarbon phenanthrene as a carbon source but also extrudes it into the extracellular medium using the efflux pump EmhABC. Because phenanthrene is considered a nontoxic carbon source for P. fluorescens WEP, its energy-dependent efflux seems counter-productive. We hypothesized that the efflux of phenanthrene would decrease the efficiency of its biodegradation. Indeed, an emhB disruptant strain, wild-type PAH catabolism, efflux negative (WEN), biodegraded 44% more phenanthrene than its parent strain WEP during a 6-day incubation. To determine whether efflux affected the degree of oxidation of phenanthrene, we quantified the conversion of ¹⁴C-phenanthrene to radiolabeled polar metabolites and ¹⁴CO₂. The emhB⁻ WEN strain produced approximately twice as much ¹⁴CO₂ and radiolabeled water-soluble metabolites as the WEP strain. In contrast, the mineralization of ¹⁴C-glucose, which is not a known EmhB efflux substrate, was equivalent in both strains. An early open-ring metabolite of phenanthrene, trans-4-(1-hydroxynaphth-2-yl)-2-oxo-3-butenoic acid, also was found to be a substrate of the EmhABC pump and accumulated in the supernatant of WEP but not WEN cultures. The analogous open-ring metabolite of dibenzothiophene, a heterocyclic analog of phenanthrene, was extruded by EmhABC plus a putative alternative efflux pump, whereas the end product 3-hydroxy-2-formylbenzothiophene was not actively extruded from either WEP or WEN cells. These results indicate that the active efflux of phenanthrene and its early metabolite(s) decreases the efficiency of phenanthrene degradation by the WEP strain. This activity has implications for the bioremediation and biocatalytic transformation of polycyclic aromatic hydrocarbons and heterocycles.

show abstract

Section: Phenanthrene Metabolite Effluxmentioning

confidence: 99%

Section: Emhabc Activity Decreases the Mineralization And Transformatmentioning

confidence: 99%

The EmhABC efflux pump decreases the efficiency of phenanthrene biodegradation by Pseudomonas fluorescens strain LP6a

Adebusuyi

Smith

Gray

et al. 2012

Appl Microbiol Biotechnol

View full text Add to dashboard Cite

show abstract

“…Research on biodesulfurization using DBT has resulted in two different biochemical pathways, named Kodama [8] after their author and 4S [9]. The Kodama pathway is considered unsuitable for treating fuel because water-soluble sulfur compounds are produced, which are thus unavailable for burning and so reduce the caloric value of the fuel.…”

Section: Introductionmentioning

confidence: 99%

Desulfurization of Dibenzothiophene by Pseudomonas fluorescens (UCP 1514) Leading to the Production of Biphenyl

Silva¹,

Schwartz²,

Souza³

et al. 2018

Recent Insights in Petroleum Science and Engineering

View full text Add to dashboard Cite

Dibenzothiophene (DBT) is a typical recalcitrant thiophenic sulfur component of fuels, and its desulphurization has been a model reaction in the treatment of these compounds. Based on this information, the potential of Pseudomonas fluorescens (UCP 1514) on the desulfurization of dibenzothiphene was studied, in order to use it for reducing the sulfur content of diesel oil in compliance with environmental regulations. The result of biodegradation by the bacteria was determined by undertaking high-performance liquid chromatography of the metabolites produced. These can also be identified by gas chromatography with a mass spectrometry detector, and doing so revealed a sulfur-free product, biphenyl, as the final product of the degradation process. The results showed a decrease of 73% in dibenzothiophene content, which means that P. fluorescens removes sulfur from dibenzothiophene with a good selectivity to form biphenyl. These promising results indicate that P. fluorescens has an interesting potential to degrade sulfur-containing compounds in diesel oil and thereby could help in removing sulfur content from diesel oil. The process of microbial desulfurization described herein can be used particularly after carrying out hydrodesulfurization. Consequently, the sulfur content could be reduced even further. Applying P. fluorescens UCP 1514 in dibenzothiophene could help to understand the nature of the biodegradation process and to achieve the regulatory standards for sulfur level in fossil fuels.

show abstract

“…In addition, although biodesulfurization has been suggested for the specific removal of sulfur compounds from fossil fuels, only a few model compounds have been used in studies attempting to demonstrate the applicability of this process (Foght et al 1990a). Most studies on the biotransformations of individual petroleum-related organosulfur compounds have focussed on the condensed thiophenes including dibenzothiophene (Kargi & Robinson 1984;Kodama et al 1973;Laborde & Gibson 1977;van Afferden et al 1990), benzothiophene (Bohonos et al 1977;Fedorak & Grbi6-Gali61991;Sagardia et al 1975), and recently some alkylbenzothiophenes (Safti6 et al 1991).…”

Section: Introductionmentioning

confidence: 99%

Aerobic microbial metabolism of some alkylthiophenes found in petroleum

Fedorak

Peakman

1992

Biodegradation

View full text Add to dashboard Cite

Six alkylthiophenes, 2-hexadecyl-5-methylthiophene (I), 2-methyl-5-tridecylthiophene (II) and 2-butyl-5-tridecylthiophene (III), 2-(3,7-dimethyloctyl)-5-methylthiophene (IV), 2-methyl-5-(3,7,11,15-tetramethylhexadecyl)thiophene (V) and 2-ethyl-5-(3,7,11,15-tetramethylhexadecyl)thiophene (VI) were synthesized and used as substrates in biodegradation studies. The products of their aerobic metabolism by pure bacterial cultures were identified. In most cases, the long alkyl chains of these thiophenes were preferentially attacked and in pure cultures of alkane-degrading bacteria, the major metabolites that accumulated in the medium were 5-methyl-2-thiopheneacetic acid from (I), 5-methyl-2-thiophenecarboxylic acid from (II) and occasionally from (V), 5-butyl-2-thiophenecarboxylic acid from (III) and 5-ethyl-2-thiopheneacetic acid from (VI). These transformations are consistent with the metabolism of the alkyl side chains via the beta-oxidation pathway. In contrast, 5-(3,7-dimethyloctyl)-2-thiophenecarboxylic acid was produced from (IV). Because it was available in greatest supply, (I) was studied most thoroughly. It supported growth of the six n-alkanedegrading bacteria tested and (I) was degraded more quickly than pristane but not as quickly as nhexadecane in mixtures of these three compounds. In the presence of Prudhoe Bay crude oil and a mixed culture of petroleum-degrading bacteria, the acid metabolites from (I), (II) and (III) underwent further biotransformations to products that were not detected by the analytical methods used. The addition of n-hexadecane to the mixed culture of petroleum-degrading bacteria also enhanced the further biotransformations of the metabolites from (I).

show abstract

Identification of Microbial Products from Dibenzothiophene and Its Proposed Oxidation Pathway

Cited by 81 publications

References 0 publications

The EmhABC efflux pump decreases the efficiency of phenanthrene biodegradation by Pseudomonas fluorescens strain LP6a

The EmhABC efflux pump decreases the efficiency of phenanthrene biodegradation by Pseudomonas fluorescens strain LP6a

Desulfurization of Dibenzothiophene by Pseudomonas fluorescens (UCP 1514) Leading to the Production of Biphenyl

Aerobic microbial metabolism of some alkylthiophenes found in petroleum

Contact Info

Product

Resources

About