Metobromuron: Acetylation of the Aniline Moiety as a Detoxification Mechanism

Tweedy, B. G.; Loeppky, Carol; Ross, James A.

doi:10.1126/science.168.3930.482

Cited by 63 publications

(34 citation statements)

References 4 publications

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“…In the environment, organic pollutants can be degraded by different biological (26), chemical (27), or photochemical (28) processes. The N-acetylation of aniline-derived herbicides has been shown to detoxify them (18,29) and has been reported to occur in soil bacteria such as Pseudomonas spp. (30)(31)(32) and M. loti (24).…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Biotransformation of Trichoderma spp. and Their Tolerance to Aromatic Amines, a Major Class of Pollutants

Cocaign

Bui

Silar

et al. 2013

Appl Environ Microbiol

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e Trichoderma spp. are cosmopolitan soil fungi that are highly resistant to many toxic compounds. Here, we show that Trichoderma virens and T. reesei are tolerant to aromatic amines (AA), a major class of pollutants including the highly toxic pesticide residue 3,4-dichloroaniline (3,4-DCA). In a previous study, we provided proof-of-concept remediation experiments in which another soil fungus, Podospora anserina, detoxifies 3,4-DCA through its arylamine N-acetyltransferase (NAT), a xenobiotic-metabolizing enzyme that enables acetyl coenzyme A-dependent detoxification of AA. To assess whether the N-acetylation pathway enables AA tolerance in Trichoderma spp., we cloned and characterized NATs from T. virens and T. reesei. We characterized recombinant enzymes by determining their catalytic efficiencies toward several toxic AA. Through a complementary approach, we also demonstrate that both Trichoderma species efficiently metabolize 3,4-DCA. Finally, we provide evidence that NAT-independent transformation is solely (in T. virens) or mainly (in T. reesei) responsible for the observed removal of 3,4-DCA. We conclude that T. virens and, to a lesser extent, T. reesei likely utilize another, unidentified, metabolic pathway for the detoxification of AA aside from acetylation. This is the first molecular and functional characterization of AA biotransformation in Trichoderma spp. Given the potential of Trichoderma for cleanup of contaminated soils, these results reveal new possibilities in the fungal remediation of AA-contaminated soil.

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Section: Resultsmentioning

confidence: 99%

“…(30)(31)(32) and M. loti (24). For instance, the herbicide metobromuron is metabolized to 4-BA, which is detoxified by certain soil microbes to acetyl-4-BA (26,29). This acetylation pathway has been characterized in the filamentous fungus P. anserina (17).…”

Section: Resultsmentioning

confidence: 99%

Biotransformation of Trichoderma spp. and Their Tolerance to Aromatic Amines, a Major Class of Pollutants

Cocaign

Bui

Silar

et al. 2013

Appl Environ Microbiol

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“…By-products of aniline-derived herbicides (such as 3,4-DCA) are among the most toxic chemicals found in soil (Dearfield et al, 1999;Harvey et al, 2002). The XME-dependent Nacetylation of these chemicals has been shown to detoxify them (Tweedy et al, 1970;Tixier et al, 2002) and has been reported to occur in soil bacteria such as Pseudomonas sp. (Vol'nova et al, 1980;Travkin et al, 2003;Westwood et al, 2005) and Mesorhizobium loti (RodriguesLima et al, 2006).…”

Section: The Fate Of Pesticide-derived Aromatic Amines In the Soil Enmentioning

confidence: 99%

“…The herbicide metobromuron is metabolized to 4-bromoaniline (4-BA), which is detoxified by certain soil microbes to acetyl-4-bromoaniline (Tweedy et al, 1970;Van Eerd et al, 2003). …”

Section: Soil Bacteria Filamentous Fungimentioning

confidence: 99%

Pesticide-Derived Aromatic Amines and Their Biotransformation

Dupret¹,

Dairou²,

Busi³

et al. 2011

Pesticides in the Modern World - Pests Control and Pesticides Exposure and Toxicity Assessment

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“…These compounds are known to be important in microbial detoxification and have been widely observed during nitroreductase-initiated degradation of nitroaromatic compounds (18,33,36,40,41,53). APX is an analog of the toxic compound actinomycin, which combines with DNA and inhibits RNA synthesis (21).…”

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confidence: 99%

Biotransformation of Hydroxylaminobenzene and Aminophenol by Pseudomonas putida 2NP8 Cells Grown in the Presence of 3-Nitrophenol

Zhao

Singh

Huang

et al. 2000

Appl Environ Microbiol

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Biotransformation products of hydroxylaminobenzene and aminophenol produced by 3-nitrophenol-grown cells of Pseudomonas putida 2NP8, a strain grown on 2-and 3-nitrophenol, were characterized. Ammonia, 2-aminophenol, 4-aminophenol, 4-benzoquinone, N-acetyl-4-aminophenol, N-acetyl-2-aminophenol, 2-aminophenoxazine-3-one, 4-hydroquinone, and catechol were produced from hydroxylaminobenzene. Ammonia, N-acetyl-2-aminophenol, and 2-aminophenoxazine-3-one were produced from 2-aminophenol. All of these metabolites were also found in the nitrobenzene transformation medium, and this demonstrated that they were metabolites of nitrobenzene transformation via hydroxylaminobenzene. Production of 2-aminophenoxazine-3-one indicated that oxidation of 2-aminophenol via imine occurred. Rapid release of ammonia from 2-aminophenol transformation indicated that hydrolysis of the imine intermediate was the dominant reaction. The low level of 2-aminophenoxazine-3-one indicated that formation of this compound was probably due to a spontaneous reaction accompanying oxidation of 2-aminophenol via imine. 4-Hydroquinone and catechol were reduction products of 2-and 4-benzoquinones. Based on these transformation products, we propose a new ammonia release pathway via oxidation of aminophenol to benzoquinone monoimine and subsequent hydrolysis for transformation of nitroaromatic compounds by 3-nitrophenol-grown cells of P. putida 2NP8. We propose a parallel mechanism for 3-nitrophenol degradation in P. putida 2NP8, in which all of the possible intermediates are postulated.Toxic nitroaromatic compounds tend to be reduced by biological systems in the environment due to electron deficiencies on the nitrogen atom or the benzene ring (6,24,37,45). Arylhydroxylamine is one of the common intermediate products during nitro group reduction. Hydroxylamines are both reductants and oxidants that attack biomolecules and have highly toxic, carcinogenic, and mutagenic effects on biological systems and human tissues (12, 22).The previously described routes for metabolism of arylhydroxylamines, which are involved in nitroreductase-initiated degradation of nitroaromatic compounds, include (i) a twoelectron reduction process that produces dead end amines, (ii) the Bamberger rearrangement-like reaction which leads to production of 2-aminophenol (2-AP) or 4-AP (31, 36, 41), and (iii) conversion into a 1,2-dihydroxyl aromatic product by hydroxylaminolyase (19,20,25,38).Only ammonia release from nitroaromatic compounds avoids production of potentially toxic amines in the environment. The following two ammonia release processes during nitroreductase-initiated aerobic degradation of nitroaromatic compounds have been described: (i) ammonia release via ring fission of AP and (ii) ammonia release before ring fission (conversion of arylhydroxylamine into 1,2-dihydroxyl aromatic compounds by proposed hydrolytic hydroxylaminolyases). Nishino and Spain (31) observed the first process in the nitrobenzene (NB) degradation pathway of Pseudomonas pseudoalcaligenes, and Groeneweg...

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Metobromuron: Acetylation of the Aniline Moiety as a Detoxification Mechanism

Cited by 63 publications

References 4 publications

Biotransformation of Trichoderma spp. and Their Tolerance to Aromatic Amines, a Major Class of Pollutants

Biotransformation of Trichoderma spp. and Their Tolerance to Aromatic Amines, a Major Class of Pollutants

Pesticide-Derived Aromatic Amines and Their Biotransformation

Biotransformation of Hydroxylaminobenzene and Aminophenol by Pseudomonas putida 2NP8 Cells Grown in the Presence of 3-Nitrophenol

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