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PubMed1973

Transmissible plasmid coding early enzymes of naphthalene oxidation in Pseudomonas putida.

The capacity of Pseudomonas putida PpG7 (ATCC 17,485) to grow on naphthalene, phenotype Nah(+), is lost spontaneously, and the frequency is increased by treatment with mitomycin C. The Nah(+) growth character can be transferred to cured or heterologous fluorescent pseudomonads lacking this capacity by conjugation, or between phage pf16-sensitive strains by transduction. After mutagenesis, strains can be selected with increased donor capacity in conjugation. Clones which use naphthalene grow on salicylate and carry catechol 2,3-oxygenase, the initial enzyme of the aromatic alpha-keto acid pathway, whereas cured strains grow neither on salicylate nor naphthalene and lack catechol 2,3-oxygenase, but retain catechol 1,2-oxygenase and the aromatic beta-keto adipate pathway enzymes.

Bacteriophages↗
PubMed1980

Metabolism of naphthalene by pseudomonads: salicylaldehyde as the first possible inducer in the metabolic pathway.

Pseudomonas ATCC 17483 produced enzymes for naphthalene metabolism when growing in a medium containing succinate and naphthalene. Mutants for naphthalene metabolism produced by treatment with N-methyl-N'-nitro-N-nitrosoguanidine were able to produce these enzymes only when the metabolic pathway was intact as far as salicylaldehyde, which was therefore identified as the first possible inducer.

Aldehyde Oxidoreductases↗
PubMed1982

Naphthalene plasmids in pseudomonads.

A rapid method beginning with the direct lysis of bacteria in alkaline sodium dodecyl sulfate was used to detect naphthalene plasmids in pseudomonads. The strains NCIB 9816, PG, ATCC 17483, and ATCC 17484, which can grow on naphthalene as the sole source of carbon and energy, were examined. All except ATCC 17483 contained more than one plasmid. ATCC 17483 did not contain any plasmids. The largest pair of plasmids found in each of NCIB 9816 and PG(NAH2 and NAH3, respectively) determined naphthalene metabolism and could be transferred by conjugation. This also transferred the unusually regulated meta pathway enzymes for catechol metabolism. NAH2 determines the constitutive production of low concentrations of catechol 2,3-dioxygenase and 2-hydroxymuconic acid semialdehyde dehydrogenase, and NAH3 determines the constitutive production of high concentration of these. NAH2 and NAH3 gave identical fragments on digestion with BamHI or HindIII, but these were quite different from those of NAH. Nonetheless, NAH2 and NAH3 hybridized with NAH.

Alcohol Oxidoreductases↗
PubMed1983

Cloning and expression in Escherichia coli of the naphthalene degradation genes from plasmid NAH7.

The genes encoding the enzymes responsible for conversion of naphthalene to 2-hydroxymuconic acid (nahA through nahI) are contained on a 25-kilobase EcoRI fragment of an 85-kilobase NAH plasmid of Pseudomonas putida. These genes were cloned into the plasmid vectors pBR322 and RSF1010 to obtain the recombinant plasmids pKGX505 and pKGX511, respectively. To facilitate cloning and analysis, an NAH7 plasmid containing a Tn5 transposon in the salicylate hydroxylase gene (nahG) was used to derive the EcoRI fragment. The genes for naphthalene degradation were expressed at a low level in Escherichia coli strains containing the fragment on the recombinant plasmids pKGX505 or pKGX511. This was shown by the ability of whole cells to convert naphthalene to salicylic acid and by in vitro enzyme assays. The expression of at least two of these genes in E. coli appeared to be regulated by the presence of the inducer salicylic acid. In addition, high-level expression and induction appear to be mediated by an NAH plasmid promoter and a regulatory gene located on the fragment. A restriction endonuclease cleavage map of the cloned fragment was generated, and the map positions of several nah genes were determined by analysis of various subcloned DNA fragments.

Cloning, Molecular↗
PubMed1992

Bacterial metabolism of naphthalene: construction and use of recombinant bacteria to study ring cleavage of 1,2-dihydroxynaphthalene and subsequent reactions.

The reactions involved in the bacterial metabolism of naphthalene to salicylate have been reinvestigated by using recombinant bacteria carrying genes cloned from plasmid NAH7. When intact cells of Pseudomonas aeruginosa PAO1 carrying DNA fragments encoding the first three enzymes of the pathway were incubated with naphthalene, they formed products of the dioxygenase-catalyzed ring cleavage of 1,2-dihydroxynaphthalene. These products were separated by chromatography on Sephadex G-25 and were identified by 1H and 13C nuclear magnetic resonance spectroscopy and gas chromatography-mass spectrometry as 2-hydroxychromene-2-carboxylate (HCCA) and trans-o-hydroxybenzylidenepyruvate (tHBPA). HCCA was detected as the first reaction product in these incubation mixtures by its characteristic UV spectrum, which slowly changed to a spectrum indicative of an equilibrium mixture of HCCA and tHBPA. Isomerization of either purified product occurred slowly and spontaneously to give an equilibrium mixture of essentially the same composition. tHBPA is also formed from HCCA by the action of an isomerase enzyme encoded by plasmid NAH7. The gene encoding this enzyme, nahD, was cloned on a 1.95-kb KpnI-BglII fragment. Extracts of Escherichia coli JM109 carrying this fragment catalyzed the rapid equilibration of HCCA and tHBPA. Metabolism of tHBPA to salicylaldehyde by hydration and aldol cleavage is catalyzed by a single enzyme encoded by a 1-kb MluI-StuI restriction fragment. A mechanism for the hydratase-aldolase-catalyzed reaction is proposed. The salicylaldehyde dehydrogenase gene, nahF, was cloned on a 2.75-kb BamHI fragment which also carries the naphthalene dihydrodiol dehydrogenase gene, nahB. On the basis of the identification of the enzymes encoded by various clones, the gene order for the nah operon was shown to be p, A, B, F, C, E, D.

Aldehyde Oxidoreductases↗
PubMed1994

Metabolism of naphthalene, fluorene, and phenanthrene: preliminary characterization of a cloned gene cluster from Pseudomonas putida NCIB 9816.

A modified cloning procedure was used to obtain large DNA insertions (20 to 30 kb) from Pseudomonas putida NCIB 9816 that expressed polycyclic aromatic hydrocarbon (PAH) transformation activity in Escherichia coli HB101. Four subclones (16 [in both orientations], 12, and 8.5 kb in size) were constructed from the initial clones. Naphthalene, fluorene, and phenanthrene transformations were investigated in these eight NCIB 9816 clones by a simple agar plate assay method, which was developed to detect and identify potential PAH metabolites. Results indicated that the necessary genes encoding the initial ring fission of the three PAHs in E. coli cells are located in an 8.5-kb EcoRI-XhoI portion, but the lower-pathway genes are not present in a 38-kb neighborhood region. These NCIB 9816 clones could transform naphthalene and phenanthrene to salicylic acid and 1-hydroxy-2-naphthoic acid, respectively. With the same clones, fluorene was degraded to 9-hydroxyfluorene, 9-fluorenone, and two unidentified compounds. Genetic similarity between the NAH7 upper-pathway genes and the cloned NCIB 9816 genes was confirmed by Southern blot DNA-DNA hybridization. In spite of this genetic similarity, the abilities of the two clusters to transform multiple PAHs were different. Under our experimental conditions, only the metabolites from naphthalene transformation by the NAH7 clone (pE317) were detected, whereas the NCIB 9816 clones produced metabolites from all three PAHs.

Biotransformation↗
PubMed1994

Cloning and characterization of a chromosomal gene cluster, pah, that encodes the upper pathway for phenanthrene and naphthalene utilization by Pseudomonas putida OUS82.

A 25-kb DNA SalI fragment cloned from the chromosomal DNA of Pseudomonas putida OUS82, which utilizes phenanthrene (Phn+) and naphthalene (Nah+), carried all of the genes necessary for upper naphthalene catabolism. Cosmid recombinant pIP7 complemented both the Nah- and Phn- defects of OUS8211 (Trp-Nah-Phn-Sal+[salicylate utilizing]Hna+[1-hydroxy-2-naphthoate utilizing]) and only the Phn- defect of OUS8212 (Trp-Nah-Phn-Sal-Hna+). The results indicate that strain OUS82 uses different pathways after o-hydroxycarboxylic aromatics in the catabolism of naphthalene and phenanthrene.

Cloning, Molecular↗
PubMed1999

NahW, a novel, inducible salicylate hydroxylase involved in mineralization of naphthalene by Pseudomonas stutzeri AN10.

Two genes, nahG and nahW, encoding two independent salicylate 1-hydroxylases have been identified in the naphthalene-degrading strain Pseudomonas stutzeri AN10. While nahG resides in the same transcriptional unit as the meta-cleavage pathway genes, forming the naphthalene degradation lower pathway, nahW is situated outside but in close proximity to this transcriptional unit. The nahG and nahW genes of P. stutzeri AN10 are induced and expressed upon incubation with salicylate, and the enzymes that are encoded, NahG and NahW, are involved in naphthalene and salicylate metabolism. Both genes, nahG and nahW, have been cloned in Escherichia coli JM109. The overexpression of these genes yields peptides with apparent molecular masses of 46 kDa (NahG) and 43 kDa (NahW), respectively. Both enzymes exhibit broad substrate specificities and metabolize salicylate, methylsalicylates, and chlorosalicylates. However, the relative rates by which the substituted analogs are transformed differ considerably.

Amino Acid Sequence↗
PubMed2003

Degradation of phenanthrene and naphthalene by a Burkholderia species strain.

Burkholderia sp. TNFYE-5 was isolated from soil for the ability to grow on phenanthrene as sole carbon and energy source. Unlike most other phenanthrene-degrading bacteria, TNFYE-5 was unable to grow on naphthalene. Growth substrate range experiments coupled with the ring-cleavage enzyme assay data suggest that TNFYE-5 initially metabolizes phenanthrene to 1-hydroxy-2-naphthoate with subsequent degradation through the phthalate and protocatechuate and beta-ketoadipate pathway. A metabolite in the degradation of naphthalene by TNFYE-5 was isolated by high-pressure liquid chromatography (HPLC) and was identified as salicylate by UV-visible spectral and gas chromatography-mass spectrometry analyses. Thus, the inability to degrade salicylate is apparently one major reason for the incapability of TNFYE-5 to grow on naphthalene.

Biodegradation, Environmental↗
PubMed1996

Repair of naphthalene-injured microdissected airways in vitro.

Nonciliated bronchiolar epithelial (Clara) cells, as both the primary target for metabolically activated pulmonary toxicants and the progenitor cell for repair after bronchiolar injury, are critical for distal airway epithelial function and regeneration. Previously, we described a model system whereby differentiated Clara cells can be maintained in culture using explants of microdissected distal airways. The purpose of this study is to establish whether distal airway explants can be used to study bronchiolar epithelial repair in vitro. Lungs from adult mice treated with naphthalene, a metabolically activated Clara cell cytotoxicant, or vehicle were inflated with agarose and distal airways were microdissected. Distal airway explants were cultured for up to 7 days in serum-free medium. Clara cells in explants from naphthalene-treated mice exhibited the characteristic cytotoxic responses previously reported in vivo when maintained in vitro: cell swelling, formation of cytoplasmic vacuoles, and exfoliation of injured cells into the airway lumen 1 to 2 days after injury (DAI). Epithelial cells squamated to cover the injured area 2 to 4 DAI. At 7 DAI, the epithelium generally consisted of cuboidal cells. Proliferating cells and marker proteins for differentiated Clara cells (Clara cell 10 kD secretory protein, or CC10, and cytochrome P450 monooxygenase isozyme 2B, or CYP2B) were detected immunochemically and their pattern of distribution during the injury and repair response in vitro paralleled the pattern of cell regeneration seen previously in vivo. We conclude that Clara cells in explants from defined regions of murine tracheobronchial airways can be used to study the early phases of the repair response to naphthalene injury, including differentiation and proliferation, in vitro.

Animals↗
PubMed2001

Flame atomic absorption spectrometric determination of trace amounts of manganese in alloys and biological samples after preconcentration with the ion pair of 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol and ammonium tetraphenylborate on microcrystalline naphthalene or by column method.

Manganese is quantitatively retained on 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol (5-Br-PADAP)-ammonium tetraphenylborate with microcrystalline naphthalene or by a column method in the pH range 7.5-10.5 from large volumes of aqueous solutions of various samples. After filtration, each solid mass consisting of the manganese complex and naphthalene was dissolved with 5 ml of dimethylformamide and the metal was determined by flame atomic absorption spectrometry. Manganese complex can alternatively be quantitatively adsorbed on ammonium tetraphenylborate-naphthalene adsorbent packed in a column and determined similarly. About 0.1 microgram of manganese can be concentrated in a column from 500 ml of aqueous sample, where its concentration is as low as 0.2 ppb. Eight replicate determinations of 1.0 ppm of manganese gave a mean absorbance of 0.224 with a relative standard deviation of 1.8%. The sensitivity for 1% absorption was 19 ppb. The interference of a large number of anions and cations has been studied and the optimized conditions developed were utilized for the trace determination of manganese in various standard samples.

Alloys↗
PubMedDate not supplied

Comparison of various measures of microbial growth kinetics in suspended and biofilm cultures during biodegradation of naphthalene.

This research focused on measurement of bacterial growth rates and activities in suspended cultures and biofilms using Pseudomonas putida (ATCC 17484) for biodegradation of naphthalene. A comparison was made of the effect of three biomass measures: optical density, total cell protein, and living cell number on the calculated rate of naphthalene disappearance. Living cell number was determined by optimizing a fluorescent staining technique and using epifluorescence microscopy. All three techniques gave similar results in terms of the specific growth rates, and in all three there was a lag time between the disappearance of naphthalene and the appearance of biomass. This was most likely a consequence of the production of intermediate products detected in the chromatograms. Inclusion of a one-hour lag time in the integrated Monod expression considerably improved the agreement between experimental and calculated values. However, further improvements to an understanding of the overall rate processes may require more detailed kinetics of the individual biochemical pathways.

Biodegradation, Environmental↗
PubMed1988

Metabolism of naphthalene in roosters.

1. The metabolism of naphthalene in roosters was similar to that in rats. At least 45% of the dose was isolated from the urine as metabolites that could be formed from arene oxide precursors. 2. Urine was the major route for excretion (79%) of 14C-naphthalene from colostomized roosters. Roosters with cannulated bile ducts excreted about 24% of the dose in bile. 3. Roosters excreted tetrahydrotrihydroxy mercapturic acids of naphthalene as major urinary metabolites which indicates either the formation of diepoxide intermediates or sequential epoxidation-conjugation processes. 4. The major biliary metabolites in rooster bile were characterized as cysteine and cysteinylglycine conjugates of tetrahydrotrihydroxynaphthalenes.

Animals↗
PubMed1999

The disposition and metabolism of naphthalene in rats.

The aim of this study was to investigate the distribution, excretion and metabolism of naphthalene-[ring-U-3H] in rats. The experiments were performed on 54 male outbred IMP: Wist rats with body weight of 200-220 g. The compound was administered intraperitoneally in olive oil in a single dose of 20 mg/kg (about 540 kBq per animal). 3H radioactivity was traced in selected organs and tissues, blood, urine and faeces, 1-72 h following the administration. The main metabolites were isolated from urine and identified by the GC-MS method. Urine and faeces proved to be the main route of tritium elimination. Over 88% of the compound was excreted during the first 72 hours. Maximum level of tritium in plasma was observed at the 2nd h after administration following a biphasic decline. Half-lifes for phases I and II were 0.8 and 99 h, respectively. In erythrocytes 3H-decline was monophasic with the half-life of about 9 h. In organs and tissues, the highest concentrations during the first hours after administration were detected in the fat, liver and kidneys. Then, gradual decline of tritium was noticed in all examined tissues. In urine of rats the following substances were identified: (1) naphthalene, (2) 1-naphthol, (3) 2-naphthol, (4) 1,2-naphthalenediol-1,2-dihydro, (5) methylthionaphthalenes (two isomers). In conclusion, naphthalene has a relatively rapid turnover rate in the rat organism and does not form considerable deposits in the tissue. The metabolism encompasses ring hydroxylation, hydration and glutathione conjugation.

Animals↗
PubMedDate not supplied

Column preconcentration of trace manganese with the ion pair of 2-nitroso-1-naphthol-4-sulfonic acid tetradecyldimethylbenzyl-ammonium chloride supported on naphthalene and determination by derivative spectrophotometry.

A column preconcentration method has been developed for the determination of trace amounts of manganese by preconcentration on 2-nitroso-1-naphthol-4-sulfonic acid (nitroso-S)-tetradecyldimethylbenzylammonium (TDBA) naphthalene as an adsorbent using a simple funnel tipped glass tube. Manganese reacts with nitroso-S to form a water soluble brown colored chelate anion. The chelate anion forms a water insoluble Mn-Nitroso-S-TDBA ion pair on naphthalene packed in a column in the pH range 9.6-10.5 at a flow rate of 1-2 ml/min. The solid mass consisting of manganese complex and naphthalene is dissolved in 5 ml of dimethylformamide (DMF) and the metal determined by second derivative spectrophotometry. The calibration curve is linear in the concentration range 0.25-35.0 micrograms of Mn in 5 ml of the final DMF solution. Eight replicate determinations of 25 micrograms of standard manganese solution give a mean peak height of 4.0 with a correlation coefficient of 0.9995 and relative standard deviation of +/- 1.1%. The sensitivity was calculated to be 0.502(d2 A/d lambda 2)/microgram ml-1 from the slope of the calibration curve. The detection limit was 0.020 microgram ml-1 for manganese at the minimum instrumental settings (signal to noise ratio = 2). Various parameters effecting the method such as the effect of pH, volume of aqueous phase and interference of a number of metal ions on the determination of manganese have been evaluated to optimize the conditions for its determination in standard alloys and biological samples.

Adsorption↗
PubMed2002

Protection of HLE B-3 cells against hydrogen peroxide- and naphthalene-induced lipid peroxidation and apoptosis by transfection with hGSTA1 and hGSTA2.

PURPOSE: To investigate the physiological role of two major alpha-class glutathione S-transferases (GSTs), hGSTA1-1 and hGSTA2-2 in protection against oxidative stress and lipid peroxidation (LPO) in human lens epithelial (HLE B-3) cells. METHODS: Total GSTs were purified from HLE B-3 cells by glutathione (GSH)-affinity chromatography and characterized by Western blot analysis, isoelectric focusing, and kinetic studies. The relative contributions of the alpha-class GSTs and the Se-dependent glutathione peroxidase (GPx)-1 in GSH-dependent reduction of phospholipid hydroperoxide (PL-OOH) were quantitated through immunoprecipitation studies using separately the specific polyclonal antibodies against human alpha-class GSTs and GPx-1. HLE B-3 cell membranes were prepared, peroxidized, and used to examine whether hGSTA1-1 and hGSTA2-2 catalyzes the reduction of membrane PL-OOH in situ using the microiodometric and spectrophotometric assays. The protective effects of the alpha-class GSTs against H2O2- and naphthalene-induced LPO and apoptosis were examined by transfecting HLE B-3 cells with cDNAs of hGSTA1 and hGSTA2. RESULTS. HLE B-3 cells expressed only the alpha and pi class GSTs. The Michaelis-Menten constant (k(m)) and turnover number (k(cat)) of purified total GSTs toward phosphatidylcholine hydroperoxide (PC-OOH) were found to be 30 +/- 4 microM and 1.95 +/- 0.26 seconds, respectively. The alpha-class GSTs accounted for approximately 65% of the total GPx activity of HLE B-3 cells toward PC-OOH. Our results demonstrate for the first time that hGSTA1-1 and hGSTA2-2 effectively catalyzed GSH-dependent reduction of membrane PL-OOH in situ in HLE B-3 cells. Transfection with hGSTA1 or hGSTA2 protected these cells from H2O2- and naphthalene-induced LPO and attenuated H2O2- and naphthalene-induced apoptosis through inhibiting caspase 3 activation. CONCLUSIONS: These results demonstrate that the alpha-class GSTs hGSTA1-1 and hGSTA2-2 play a major role as antioxidant enzymes and are the main determinants of the levels of LPO caused by oxidative stress in human lens epithelial cells.

Animals↗
PubMed2003

Isolation of naphthalene-degrading bacteria from tropical marine sediments.

Oil pollution is a major environmental concern in many countries, and this has led to a concerted effort in studying the feasibility of using oil-degrading bacteria for bioremediation. Although many oil-degrading bacteria have been isolated from different environments, environmental conditions can impose a selection pressure on the types of bacteria that can reside in a particular environment. This study reports the successful isolation of two indigenous naphthalene-degrading bacteria from oil-contaminated tropical marine sediments by enrichment culture. Strains MN-005 and MN-006 were characterized using an extensive range of biochemical tests. The 16S ribosomal deoxyribonucleic acid (rDNA) sequence analysis was also performed for the two strains. Their naphthalene degradation capabilities were determined using gas chromatography and DAPI counting of bacterial cells. Strains MN-005 and MN-006 are phenotypically and phylogenetically different from each other, and belong to the genera Staphylococcus and Micrococcus, respectively. Strains MN-005 and MN-006 had maximal specific growth rates (micro(max)) of 0.082 +/- 0.008 and 0.30 +/- 0.02 per hour, respectively, and half-saturation constants (K(s)) of 0.79 +/- 0.10 and 2.52 +/- 0.32 mg per litre, respectively. These physiological and growth studies are useful in assessing the potential of these indigenous isolates for in situ or ex situ naphthalene pollutant bioremediation in tropical marine environments.

Biodegradation, Environmental↗
PubMedDate not supplied

[Identification of the key genes of naphthalene catabolism in soil DNA].

The key genes nahAc and xylE of the naphthalene catabolism of fluorescent Pseudomonas spp. in the total soil DNA samples were detected by the polymerase chain reaction (PCR) technique. The collection of fluorescent Pseudomonas spp. was screened for the occurrence of these genes. The results obtained show the possibility of using this approach in the goal-directed search for plasmid-containing naphthalene-degrading fluorescent pseudomonads in soil. The distribution of the naphthalene catabolism genes in soils contaminated with creosote and petroleum products was also studied.

Biodegradation, Environmental↗