The Regulation of Naphthalene Oxygenase in Pseudomonads

Shamsuzzaman, Kazi; Barnsley, E. A.

doi:10.1099/00221287-83-1-165

Cited by 64 publications

(39 citation statements)

References 3 publications

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“…SRS16. Positive regulation of the degradation pathway of (chloro)aromatic compounds by its pathway intermediates has been described previously (33,41). As such, previously reported linuron induction of linuron mineralization by SRS16 in cultures containing mg-liter Ϫ1 linuron concentrations but not in cultures containing g-liter Ϫ1 concentrations (47) can be explained by the observed background expression of libA and its downstream genes, which would allow linuron mineralization at low concentrations even without pre-exposure to linuron.…”

Section: Resultsmentioning

confidence: 89%

A Novel Hydrolase Identified by Genomic-Proteomic Analysis of Phenylurea Herbicide Mineralization by Variovorax sp. Strain SRS16

Bers

Leroy

Breugelmans

et al. 2011

Appl Environ Microbiol

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The soil bacterial isolate Variovorax sp. strain SRS16 mineralizes the phenylurea herbicide linuron. The proposed pathway initiates with hydrolysis of linuron to 3,4-dichloroaniline (DCA) and N,O-dimethylhydroxylamine, followed by conversion of DCA to Krebs cycle intermediates. Differential proteomic analysis showed a linuron-dependent upregulation of several enzymes that fit into this pathway, including an amidase (LibA), a multicomponent chloroaniline dioxygenase, and enzymes associated with a modified chlorocatechol ortho- The phenylurea herbicide linuron is a nonselective preemergent herbicide that acts as a photosystem II inhibitor. The herbicide is globally used to control a wide variety of annual and perennial broadleaf and grassy weeds in agricultural land. Microbial degradation is considered an important mechanism in the dissipation of linuron and other phenylurea herbicides in the environment. Several bacterial strains (39, 46), as well as consortia (5, 10), able to degrade and even use the compound as a sole source of carbon and nitrogen have been reported. Although derived from different geographical locations, most of the linuron-catabolizing isolates, either individual strains or key members of linurondegrading consortia, belong to the genus Variovorax. This suggests that this genus plays an important role in linuron degradation in soil. The proposed pathway of linuron catabolism starts with amide hydrolysis to 3,4-dichloroaniline (DCA) and N,O-dimethylhydroxylamine (N,O-DMHA) (Fig. 1). DCA is harmful and recalcitrant, while N,O-DMHA is not and degraded easily. Several linuron-degrading Variovorax strains, in addition to mediating linuron hydrolysis, are able to use DCA as the sole carbon source and mineralize it. To date, little is known about the genes and enzymes responsible for linuron and DCA degradation. Engelhardt et al. (13) described an arylacyl amidase responsible for conversion of linuron to DCA in Bacillus sphaericus ATCC 12123. In addition, phenylurea hydrolase-encoding genes puhA and puhB were identified in the linuron-degrading actinomycetes Arthrobacter globiformis D47 (52) and Mycobacterium brisbanense JK1 (23), respectively. PuhA and PuhB form a novel branch within the metal-dependent amidohydrolase superfamily (23). Regarding the degradation of DCA, Dejonghe (9) and Breugelmans et al. (6) found indications for the involvement of a multicomponent aniline dioxygenase enzyme in DCA degradation in Variovorax sp. strain WDL1. However, the genes responsible for DCA degradation in linuron-mineralizing bacteria have not yet been identified.We report here on the identification of the linuron and DCA degradation genes in the linuron-mineralizing strain Variovorax sp. strain SRS16 (46). The enzyme responsible for hydrolysis of linuron was purified and characterized. The expression of the catabolic genes under different conditions

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Section: Resultsmentioning

confidence: 89%

A Novel Hydrolase Identified by Genomic-Proteomic Analysis of Phenylurea Herbicide Mineralization by Variovorax sp. Strain SRS16

Bers

Leroy

Breugelmans

et al. 2011

Appl Environ Microbiol

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“…Naphthalene dioxygenase was assayed spectrophotometrically with whole cells as described by Shamsuzzaman and Barnsley (36 (10 ml) was incubated at 30°C in 100-ml Erlenmeyer flasks, 2NS (1 mM) was added, and the suspension was vigorously shaken. Every 10 min, a sample was taken and the cells were removed by centrifugation; the concentration of 2NS was determined by highpressure liquid chromatography (HPLC).…”

Section: Methodsmentioning

confidence: 99%

“…strain NCIB 9816, Pseudomonas sp. strain NCIB 10535, and P. putida KT2442 NAH7 on naphthalene culture media were prepared as described by Shamsuzzaman and Barnsley (36).…”

Section: Methodsmentioning

confidence: 99%

Purification and characterization of a 1,2-dihydroxynaphthalene dioxygenase from a bacterium that degrades naphthalenesulfonic acids

et al. 1991

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1,2-Dihydroxynaphthalene dioxygenase was purified to homogeneity from a bacterium that degrades naphthalenesulfonic acids (strain BN6). The enzyme requires Fe2" for maximal activity and consists of eight identical subunits with a molecular weight of about 33,000. Analysis of the NH2-terminal amino acid sequence revealed a high degree of homology (22 of 29 amino acids) with the NH2-terminal amino acid sequence of 2,3-dihydroxybiphenyl dioxygenase from strain Pseudomonas paucimobiis Ql. 1,2-Dihydroxynaphthalene dioxygenase from strain BN6 shows a wide substrate specificity and also cleaves 5-, 6-, and 7-hydroxy-1,2-dihydroxynaphthalene, 2,3-and 3,4-dihydroxybiphenyl, catechol, and 3-methyl-and 4-methylcatechol. Similar activities against the hydroxy-1,2-dihydroxynaphthalenes were also found in cell extracts from naphthalenedegrading bacteria.Amino-and hydroxynaphthalenesulfonic acids (ANS and HNS, respectively) serve as building blocks for the largescale synthesis of azo dyes. Since arylsulfonates are very rare among natural compounds (21), naphthalenesulfonic acids are referred to as xenobiotics. Arylsulfonates are major pollutants of the environment, and the contamination of the Rhine River by sulfur-organic compounds is largely due to this class of compounds (25). Nevertheless, bacteria which degrade naphthalenesulfonic acids have repeatedly been isolated (4, 5, 29-31, 41, 43). Brilon et al. (4, 5) selected pseudomonads which degraded naphthalene-2-sulfonic acid (2NS) and naphthalene-1-sulfonic acid (1NS). The initial reaction in the degradation of iNS and 2NS is catalyzed by a 1,2-dioxygenase which weakens the carbon-sulfur bond.

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“…To detect product accumulation, mutant strains were grown overnight (16 hr) in 5 ml of phosphate ammonium salts supplemented with methionine (50 ,ug/ml) with 20 mM monosodium glutamate as a secondary carbon source, 0.3 mM 2-aminobenzoate as gratuitous inducer (29,30), and 4 mM naphthalene, added in dimethylformamide. Cells were removed by centrifugation, the supernatant was diluted in neutral 100 mM phosphate buffer, and the accumulated products were identified by spectral measurements over the range 240 to 500 nm at pH 3 (adjusted with HCl), pH 7, and pH 12 (adjusted with NaOH).…”

Section: Methodsmentioning

confidence: 99%

Plasmid gene organization: naphthalene/salicylate oxidation.

Yen¹,

Gunsalus²

1982

Proc. Natl. Acad. Sci. U.S.A.

242

160

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Genes for naphthalene metabolism are localized on nah7, an 83-kilobase (kb) plasmid, in two gene clusters under salicylate control. Polar mutations formed by insertion of the transposon Tn5 permit detection ofthe transcription direction and the gene organization within two ""10-kb DNA segments separated by a -7-kb regulatory gene region. The gene cluster specifying conversion of naphthalene to salicylate lies near the left initiation of a 25-kb DNA fragment A released by EcoRI; that for the salicylate pathway via catechol meta-fission lies near the right terminus with extension into the adjoining 5.9-kb fragment C. The genetic organization and regulation resemble the tol plasmid-encoded "upper" and "lower" pathways of toluene/xylene oxidation in Pseudomonas putida mt2.

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The Regulation of Naphthalene Oxygenase in Pseudomonads

Cited by 64 publications

References 3 publications

A Novel Hydrolase Identified by Genomic-Proteomic Analysis of Phenylurea Herbicide Mineralization by Variovorax sp. Strain SRS16

A Novel Hydrolase Identified by Genomic-Proteomic Analysis of Phenylurea Herbicide Mineralization by Variovorax sp. Strain SRS16

Purification and characterization of a 1,2-dihydroxynaphthalene dioxygenase from a bacterium that degrades naphthalenesulfonic acids

Plasmid gene organization: naphthalene/salicylate oxidation.

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