scholarly journals Epoxy Coenzyme A Thioester Pathways for Degradation of Aromatic Compounds

2012 ◽  
Vol 78 (15) ◽  
pp. 5043-5051 ◽  
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.

Degradation of Aromatic Compounds in Plants Grown under Aseptic Conditions

2005 ◽  
Vol 60 (1-2) ◽  
pp. 97-102 ◽  
Author(s):  
Teimuraz Mithaishvili ◽  
René Scalla ◽  
Devi Ugrekhelidze ◽  
Benedict Tsereteli ◽  
Tinatin Sadunishvili ◽  
...  
Keyword(s):  
Aromatic Ring ◽  
Aromatic Compounds ◽  
Higher Plants ◽  
Environmental Pollutants ◽  
Krebs Cycle ◽  
Oxidative Degradation ◽  
Transformation Products ◽  
Ring Cleavage ◽  
Intermediate Transformation ◽  
Aromatic Ring Cleavage

The aim of the work is to investigate the ability of higher plants to absorb and detoxify environmental pollutants - aromatic compounds via aromatic ring cleavage. Transformation of 14C specifically labelled benzene derivatives, [1-6-14C]-nitrobenzene, [1-6-14C]-aniline, [1-14C]- and [7-14C]-benzoic acid, in axenic seedlings of maize (Zea mays L.), kidney bean (Phaseolus vulgaris L.), pea (Pisum sativum L.) and pumpkin (Cucurbita pepo L.) were studied. After penetration in plants, the above xenobiotics are transformed by oxidative or reductive reactions, conjugation with cell endogenous compounds, and binding to biopolymers. The initial stage of oxidative degradation consists in hydroxylation reactions. The aromatic ring can then be cleaved and degraded into organic acids of the Krebs cycle. Ring cleavage is accompanied by 14CO2 evolution. Aromatic ring cleavage in plants has thus been demonstrated for different xenobiotics carrying different substitutions on their benzene ring. Conjugation with low molecular peptides is the main pathway of aromatic xenobiotics detoxification. Peptide conjugates are formed both by the initial xenobiotics (except nitrobenzene) and by intermediate transformation products. The chemical nature of the radioactive fragment and the amino acid composition of peptides participating in conjugation were identified.

scholarly journals A genomic analysis of the catabolism of aromatic compounds in Azospirillum brasilense SR80

2020 ◽  
Author(s):  
Ye. V. Kryuchkova ◽  
G. L. Burygin ◽  
N. E. Gogoleva ◽  
Y. V. Gogolev ◽  
E. I. Shagimardanova ◽  
...  
Keyword(s):  
Aromatic Ring ◽  
Aromatic Compounds ◽  
Azospirillum Brasilense ◽  
Genomic Analysis ◽  
Ring Cleavage

We performed a genomic analysis of the presence and organization of oxygenases involved in the hydroxylation of various substrates, including the aromatic ring, and dioxygenases catalyzing a ring-cleavage of the formed hydroxylated intermediates in A. brasilense SR80.

scholarly journals Aerobic Benzoyl-Coenzyme A (CoA) Catabolic Pathway in Azoarcus evansii: Conversion of Ring Cleavage Product by 3,4-Dehydroadipyl-CoA Semialdehyde Dehydrogenase

2006 ◽  
Vol 188 (8) ◽  
pp. 2919-2927 ◽  
Author(s):  
Johannes Gescher ◽  
Wael Ismail ◽  
Ellen Ölgeschläger ◽  
Wolfgang Eisenreich ◽  
Jürgen Wörth ◽  
...  
Keyword(s):  
Aldehyde Dehydrogenase ◽  
Coenzyme A ◽  
Cleavage Product ◽  
Ring Cleavage ◽  
Resonance Spectroscopy ◽  
Catabolic Pathway ◽  
Semialdehyde Dehydrogenase ◽  
Cell Extracts ◽  
Genes Encoding ◽  
Coa Thioesters

ABSTRACT Benzoate, a strategic intermediate in aerobic aromatic metabolism, is metabolized in various bacteria via an unorthodox pathway. The intermediates of this pathway are coenzyme A (CoA) thioesters throughout, and ring cleavage is nonoxygenolytic. The fate of the ring cleavage product 3,4-dehydroadipyl-CoA semialdehyde was studied in the β-proteobacterium Azoarcus evansii. Cell extracts contained a benzoate-induced, NADP+-specific aldehyde dehydrogenase, which oxidized this intermediate. A postulated putative long-chain aldehyde dehydrogenase gene, which might encode this new enzyme, is located on a cluster of genes encoding enzymes and a transport system required for aerobic benzoate oxidation. The gene was expressed in Escherichia coli, and the maltose-binding protein-tagged enzyme was purified and studied. It is a homodimer composed of 54 kDa (without tag) subunits and was confirmed to be the desired 3,4-dehydroadipyl-CoA semialdehyde dehydrogenase. The reaction product was identified by nuclear magnetic resonance spectroscopy as the corresponding acid 3,4-dehydroadipyl-CoA. Hence, the intermediates of aerobic benzoyl-CoA catabolic pathway recognized so far are benzoyl-CoA; 2,3-dihydro-2,3-dihydroxybenzoyl-CoA; 3,4-dehydroadipyl-CoA semialdehyde plus formate; and 3,4-dehydroadipyl-CoA. The further metabolism is thought to lead to 3-oxoadipyl-CoA, the intermediate at which the conventional and the unorthodox pathways merge.

scholarly journals Oxidation Reactions of Marchantin A Trimethyl Ether and Some Aromatic Compounds using m-Chloroperbenzoic Acid. Formation of Muconic Acid Ester and m-Chlorobenzoate

1999 ◽  
Vol 23 (8) ◽  
pp. 470-471
Author(s):  
Motoo Tori ◽  
Masakazu Sono ◽  
Keiko Takikawa ◽  
Reiko Matsuda ◽  
Masao Toyota ◽  
...  
Keyword(s):  
Aromatic Ring ◽  
Methyl Ether ◽  
Aromatic Compounds ◽  
Acid Ester ◽  
Acid Formation ◽  
Oxidation Reactions ◽  
Muconic Acid ◽  
Trimethyl Ether

On treatment with m-chloroperbenzoic acid, dihydroeugenol methyl ether and marchantin A trimethyl ether afford muconic acid ester derivatives by oxidation of the aromatic ring as well as hydroxylated derivatives; the m-chlorobenzoate of the dihydroeugenol derivative is also observed for the former.

Mechanism of aromatic ring cleavage of a .beta.-biphenylyl ether dimer catalyzed by lignin peroxidase of Phanerochaete chrysosporium

Biochemistry ◽  
1988 ◽  
Vol 27 (13) ◽  
pp. 4787-4794 ◽  
Author(s):  
Keiji Miki ◽  
Ryuichiro Kondo ◽  
V. Renganathan ◽  
Mary B. Mayfield ◽  
Michael H. Gold
Keyword(s):  
Aromatic Ring ◽  
Phanerochaete Chrysosporium ◽  
Lignin Peroxidase ◽  
Ring Cleavage ◽  
Aromatic Ring Cleavage

Biochemical pathway and degradation of phthalate ester isomers by bacteria

2005 ◽  
Vol 52 (8) ◽  
pp. 241-248 ◽  
Author(s):  
J.-D. Gu ◽  
J. Li ◽  
Y. Wang
Keyword(s):  
Aromatic Ring ◽  
Enrichment Culture ◽  
Klebsiella Oxytoca ◽  
Sole Source ◽  
Phthalate Ester ◽  
Ring Cleavage ◽  
Mangrove Sediment ◽  
Individual Species ◽  
Dimethyl Phthalate ◽  
Dimethyl Phthalate Ester

Degradation of dimethyl isophthalate (DMI) and dimethyl phthalate ester (DMPE) was investigated using microorganisms isolated from mangrove sediment of Hong Kong Mai Po Nature Reserve. One enrichment culture was capable of utilizing DMI as the sole source of carbon and energy, but none of the bacteria in the enrichment culture was capable of degrading DMI alone. In co-culture of two bacteria, degradation was observed proceeding through monomethyl isophthalate (MMI) ester and isophthalic acid (IPA) before the aromatic ring opening. Using DMI as the sole carbon and energy source, Klebsiella oxytoca Sc and Methylobacterium mesophilicum Sr degraded DMI through the biochemical cooperation. The initial hydrolytic reaction of the ester bond was by K. oxytoca Sc and the next step of transformation was by M. mesophilicum Sr, and IPA was degraded by both of them. In another investigation, a novel bacterium, strain MPsc, was isolated for degradation of dimethyl phthalate ester (DMPE) also from the mangrove sediment. On the basis of phenotypic, biochemical and 16S rDNA gene sequence analyses, the strain MPsc should be considered as a new bacterium at the genus level (8% differences). This strain, together with a Rhodococcus zopfii isolated from the same mangrove sediment, was able to degrade DMPE aerobically. The consortium consisting of the two species degraded 450mg/l DMPE within 3 days as the sole source of carbon and energy, but none of the individual species alone was able to transform DMPE. Furthermore, the biochemical degradation pathway proceeded through monomethyl phthalate (MMP), phthalic acid (PA) and then protocatechuate before aromatic ring cleavage. Our results suggest that degradation of complex organic compounds including DMI and DMPE may be carried out by several members of microorganisms working together in the natural environments.

scholarly journals An aerobic link between lignin degradation and C1 metabolism: growth on methoxylated aromatic compounds by members of the genus Methylobacterium

2019 ◽  
Author(s):  
Jessica A. Lee ◽  
Sergey Stolyar ◽  
Christopher J. Marx
Keyword(s):  
Comparative Genomics ◽  
Aromatic Ring ◽  
Aromatic Compounds ◽  
Lignin Degradation ◽  
Comprehensive Description ◽  
Aromatic Polymer ◽  
C1 Metabolism ◽  
Polycyclic Aromatic ◽  
Methoxylated Aromatic ◽  
Aromatic Catabolism

AbstractMicroorganisms faces many barriers in the degradation of the polycyclic aromatic polymer lignin, one of which is an abundance of methoxy substituents. Demethoxylation of lignin-derived aromatic monomers in aerobic environments releases formaldehyde, a potent cellular toxin that organisms must eliminate in order to further degrade the aromatic ring. Here we provide the first comprehensive description of the ecology and evolution of the catabolism of methoxylated aromatics in the genus Methylobacterium, a plant-associated genus of methylotrophs capable of using formaldehyde for growth. Using comparative genomics, we found that the capacity for aromatic catabolism is ancestral to two clades, but has also been acquired horizontally by other members of the genus. Through laboratory growth assays, we demonstrated that several Methylobacterium strains can grow on p-hydroxybenzoate, protocatechuate, vanillate, and ferulate; furthermore, whereas non-methylotrophs excrete formaldehyde as a byproduct during growth on vanillate, Methylobacterium do not. Finally, we surveyed published metagenome data to find that vanillate-degrading Methylobacterium can be found in many soil and rhizosphere ecosystems but is disproportionately prominent in the phyllosphere, and the most highly represented clade in the environment (the root-nodulating species M. nodulans) is one with few cultured representatives.

Sign in / Sign up

Export Citation Format

Share Document