Bacterial degradation of aromatic compounds via angular dioxygenation.

ABSTRACT Hydroxylamino aromatic compounds are converted to either the corresponding aminophenols or protocatechuate during the bacterial degradation of nitroaromatic compounds. The origin of the hydroxyl group of the products could be the substrate itself (intramolecular transfer mechanism) or the solvent water (intermolecular transfer mechanism). The conversion of hydroxylaminobenzene to 2-aminophenol catalyzed by a mutase from Pseudomonas pseudoalcaligenes JS45 proceeds by an intramolecular hydroxyl transfer. The conversions of hydroxylaminobenzene to 2- and 4-aminophenol by a mutase from Ralstonia eutropha JMP134 and to 4-hydroxylaminobenzoate to protocatechuate by a lyase from Comamonas acidovorans NBA-10 and Pseudomonas sp. strain 4NT were proposed, but not experimentally proved, to proceed by the intermolecular transfer mechanism. GC-MS analysis of the reaction products formed in H2 18O did not indicate any 18O-label incorporation during the conversion of hydroxylaminobenzene to 2- and 4-aminophenols catalyzed by the mutase from R. eutropha JMP134. During the conversion of 4-hydroxylaminobenzoate catalyzed by the hydroxylaminolyase from Pseudomonas sp. strain 4NT, only one of the two hydroxyl groups in the product, protocatechuate, was 18O labeled. The other hydroxyl group in the product must have come from the substrate. The mutase in strain JS45 converted 4-hydroxylaminobenzoate to 4-amino-3-hydroxybenzoate, and the lyase in Pseudomonas strain 4NT converted hydroxylaminobenzene to aniline and 2-aminophenol but not to catechol. The results indicate that all three types of enzyme-catalyzed rearrangements of hydroxylamino aromatic compounds proceed via intramolecular transfer of hydroxyl groups.

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Epoxy Coenzyme A Thioester Pathways for Degradation of Aromatic Compounds

Applied and Environmental Microbiology ◽

10.1128/aem.00633-12 ◽

2012 ◽

Vol 78 (15) ◽

pp. 5043-5051 ◽

Cited By ~ 19

Author(s):

Wael Ismail ◽

Johannes Gescher

Keyword(s):

Aromatic Ring ◽

Aromatic Compounds ◽

Coenzyme A ◽

Environmental Pollutants ◽

Bacterial Degradation ◽

Ring Cleavage ◽

The Novel ◽

Energy Consuming ◽

Coa Thioesters ◽

Hydrolytic Mechanism

ABSTRACTAromatic compounds (biogenic and anthropogenic) are abundant in the biosphere. Some of them are well-known environmental pollutants. Although the aromatic nucleus is relatively recalcitrant, microorganisms have developed various catabolic routes that enable complete biodegradation of aromatic compounds. The adopted degradation pathways depend on the availability of oxygen. Under oxic conditions, microorganisms utilize oxygen as a cosubstrate to activate and cleave the aromatic ring. In contrast, under anoxic conditions, the aromatic compounds are transformed to coenzyme A (CoA) thioesters followed by energy-consuming reduction of the ring. Eventually, the dearomatized ring is opened via a hydrolytic mechanism. Recently, novel catabolic pathways for the aerobic degradation of aromatic compounds were elucidated that differ significantly from the established catabolic routes. The new pathways were investigated in detail for the aerobic bacterial degradation of benzoate and phenylacetate. In both cases, the pathway is initiated by transforming the substrate to a CoA thioester and all the intermediates are bound by CoA. The subsequent reactions involve epoxidation of the aromatic ring followed by hydrolytic ring cleavage. Here we discuss the novel pathways, with a particular focus on their unique features and occurrence as well as ecological significance.

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Bacterial Degradation of Aromatic Compounds

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph6010278 ◽

2009 ◽

Vol 6 (1) ◽

pp. 278-309 ◽

Cited By ~ 451

Author(s):

Jong-Su Seo ◽

Young-Soo Keum ◽

Qing Li

Keyword(s):

Aromatic Compounds ◽

Bacterial Degradation

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Iron acquisition system of Sphingobium sp. strain SYK-6, a degrader of lignin-derived aromatic compounds

10.1101/2020.03.26.005173 ◽

2020 ◽

Author(s):

Masaya Fujita ◽

Taichi Sakumoto ◽

Kenta Tanatani ◽

Hong Yang Yu ◽

Kosuke Mori ◽

...

Keyword(s):

Outer Membrane ◽

Aromatic Compounds ◽

Iron Uptake ◽

Iron Acquisition ◽

Essential Element ◽

Acquisition System ◽

Bacterial Degradation ◽

Iron Acquisition System ◽

Iron Transporter ◽

Outer Membrane Transporters

AbstractIron, an essential element for all organisms, acts as a cofactor of enzymes in bacterial degradation of recalcitrant aromatic compounds. The bacterial family, Sphingomonadaceae comprises various degraders of recalcitrant aromatic compounds; however, little is known about their iron acquisition system. Here, we investigated the iron acquisition system in a model bacterium capable of degrading lignin-derived aromatics, Sphingobium sp. strain SYK-6. Analyses of SYK-6 mutants revealed that FiuA (SLG_34550), a TonB-dependent receptor (TBDR), was the major outer membrane iron transporter. Three other TBDRs encoded by SLG_04340, SLG_04380, and SLG_10860 also participated in iron uptake, and tonB2 (SLG_34550), one of the six tonB comprising the Ton complex which enables TBDR-mediated transport was critical for iron uptake. The ferrous iron transporter FeoB (SLG_36840) played an important role in iron uptake across the inner membrane. The promoter activities of most of the iron uptake genes were induced under iron-limited conditions, and their regulation is controlled by SLG_29410 encoding the ferric uptake regulator, Fur. Although feoB, among all the iron uptake genes identified is highly conserved in Sphingomonad strains, the outer membrane transporters seem to be diversified. Elucidation of the iron acquisition system promises better understanding of the bacterial degradation mechanisms of aromatic compounds.

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Function of Coenzyme F420 in Aerobic Catabolism of 2,4,6-Trinitrophenol and 2,4-Dinitrophenol by Nocardioides simplex FJ2-1A

Journal of Bacteriology ◽

10.1128/jb.181.9.2669-2674.1999 ◽

1999 ◽

Vol 181 (9) ◽

pp. 2669-2674 ◽

Cited By ~ 66

Author(s):

Sybille Ebert ◽

Paul-Gerhard Rieger ◽

Hans-Joachim Knackmuss

Keyword(s):

Aromatic Compounds ◽

Enzyme System ◽

Picric Acid ◽

Methanobacterium Thermoautotrophicum ◽

Bacterial Degradation ◽

Coenzyme F420 ◽

Terminal Sequence ◽

Aromatic System ◽

Two Component ◽

Protein Components

ABSTRACT 2,4,6-Trinitrophenol (picric acid) and 2,4-dinitrophenol were readily biodegraded by the strain Nocardioides simplexFJ2-1A. Aerobic bacterial degradation of these π-electron-deficient aromatic compounds is initiated by hydrogenation at the aromatic ring. A two-component enzyme system was identified which catalyzes hydride transfer to picric acid and 2,4-dinitrophenol. Enzymatic activity was dependent on NADPH and coenzyme F420. The latter could be replaced by an authentic preparation of coenzyme F420 fromMethanobacterium thermoautotrophicum. One of the protein components functions as a NADPH-dependent F420 reductase. A second component is a hydride transferase which transfers hydride from reduced coenzyme F420 to the aromatic system of the nitrophenols. The N-terminal sequence of the F420 reductase showed high homology with an F420-dependent NADP reductase found in archaea. In contrast, no N-terminal similarity to any known protein was found for the hydride-transferring enzyme.

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Bacterial degradation of monocyclic aromatic compounds in kraft lignin

10.26226/morressier.5f3392ca9d1718ca4c8b2f2d ◽

2020 ◽

Author(s):

Marija Ljesevic

Keyword(s):

Aromatic Compounds ◽

Kraft Lignin ◽

Bacterial Degradation

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Metabolic Diversity in Bacterial Degradation of Aromatic Compounds

OMICS A Journal of Integrative Biology ◽

10.1089/omi.2007.0004 ◽

2007 ◽

Vol 11 (3) ◽

pp. 252-279 ◽

Cited By ~ 47

Author(s):

Prashant S. Phale ◽

Aditya Basu ◽

Prabin D. Majhi ◽

Jaigeeth Deveryshetty ◽

C. Vamsee-Krishna ◽

...

Keyword(s):

Aromatic Compounds ◽

Bacterial Degradation ◽

Metabolic Diversity

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Diverse Oxygenations Catalyzed by Carbazole 1,9a-Dioxygenase from Pseudomonas sp. Strain CA10

Journal of Bacteriology ◽

10.1128/jb.181.10.3105-3113.1999 ◽

1999 ◽

Vol 181 (10) ◽

pp. 3105-3113 ◽

Cited By ~ 103

Author(s):

Hideaki Nojiri ◽

Jeong-Won Nam ◽

Mikiko Kosaka ◽

Ken-Ichi Morii ◽

Tetsuo Takemura ◽

...

Keyword(s):

Mass Spectrometry ◽

Aromatic Hydrocarbons ◽

Aromatic Compounds ◽

Angular Position ◽

The Other ◽

Gas Chromatography Mass Spectrometry ◽

Pseudomonas Sp ◽

Polycyclic Aromatic ◽

Angular Dioxygenation ◽

Strain Ca10

ABSTRACT Carbazole 1,9a-dioxygenase (CARDO) from Pseudomonas sp. strain CA10 is a multicomponent enzyme that catalyzes the angular dioxygenation of carbazole, dibenzofuran, and dibenzo-p-dioxin. It was revealed by gas chromatography-mass spectrometry and 1H and 13C nuclear magnetic resonance analyses that xanthene and phenoxathiin were converted to 2,2′,3-trihydroxydiphenylmethane and 2,2′,3-trihydroxydiphenyl sulfide, respectively. Thus, for xanthene and phenoxathiin, angular dioxygenation by CARDO occurred at the angular position adjacent to the oxygen atom to yield hetero ring-cleaved compounds. In addition to the angular dioxygenation, CARDO catalyzed the cis dihydroxylation of polycyclic aromatic hydrocarbons and biphenyl. Naphthalene and biphenyl were converted by CARDO tocis-1,2-dihydroxy-1,2-dihydronaphthalene andcis-2,3-dihydroxy-2,3-dihydrobiphenyl, respectively. On the other hand, CARDO also catalyzed the monooxygenation of sulfur heteroatoms in dibenzothiophene and of the benzylic methylenic group in fluorene to yield dibenzothiophene-5-oxide and 9-hydroxyfluorene, respectively. These results indicate that CARDO has a broad substrate range and can catalyze diverse oxygenation: angular dioxygenation,cis dihydroxylation, and monooxygenation. The diverse oxygenation catalyzed by CARDO for several aromatic compounds might reflect the differences in the binding of the substrates to the reaction center of CARDO.

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