Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 10 de 10
Filter
Add more filters










Publication year range
1.
J Gen Appl Microbiol ; 57(5): 277-84, 2011.
Article in English | MEDLINE | ID: mdl-22139456

ABSTRACT

Five Burkholderia strains (CL-1, CL-2, CL-3, CL-4, and CL-5) capable of degrading monochloroacetic acid (MCA) were isolated from activated sludge or soil samples gathered from several parts of Japan. All five isolates were able to grow on MCA as the sole source of carbon and energy, and argentometry and gas chromatography-mass spectroscopy analyses showed that these five strains consumed MCA completely and released chloride ions stoichiometrically within 25 h. The five isolates also grew on monobromoacetic acid, monoiodoacetic acid, and L-2-monochloropropionic acid as sole sources of carbon and energy. In addition, the five isolates could not grow with DCA but dehalogenate single chlorine from DCA. Because PCR analyses revealed that all five isolates have an identical group II dehalogenase gene fragment and no group I deh gene, only strain CL-1 was analyzed further. The partial amino acid sequence of the group II dehalogenase of strain CL-1, named DehCL1, showed 74.6% and 65.2% identities to corresponding regions of the two MCA dehalogenases, DehCI from Pseudomonas sp. strain CBS-3 and Hdl IVa from Burkholderia cepacia strain MBA4, respectively. The secondary-structure motifs of the haloacid dehalogenase (HAD) superfamily and the amino acid residues involved in substrate binding, catalysis, and hydrophobic pocket formation were conserved in the partial amino acid sequence of DehCL1.


Subject(s)
Acetates/metabolism , Burkholderia/isolation & purification , Sewage/microbiology , Soil Microbiology , Amino Acid Sequence , Base Sequence , Biodegradation, Environmental , Burkholderia/genetics , Burkholderia/growth & development , Burkholderia/metabolism , Energy Metabolism , Genes, Bacterial , Hydrolases/chemistry , Hydrolases/genetics , Hydrolases/metabolism , Iodoacetic Acid/metabolism , Japan , Molecular Sequence Data , Sequence Alignment , Sequence Analysis, DNA , Sequence Analysis, Protein
2.
Molecules ; 16(8): 6844-57, 2011 Aug 10.
Article in English | MEDLINE | ID: mdl-21832974

ABSTRACT

New podand-type fluoroionophores having two pyrene moieties: 2,2´-bis(1-pyrenylacetyloxy)diphenyl sulfide (3), 2,2´-bis(1-pyrenylacetyloxy)diphenyl sulfoxide (4), and 2,2´-bis(1-pyrenylacetyloxy)diphenyl sulfone (5), have been synthesized by connecting two 1-pyrenecarbonylmethyl groups with the two hydroxy groups of 2,2´-dihydroxydiphenyl sulfide, sulfoxide, and sulfone, respectively. Their complexation behavior toward alkali metal ions was examined by fluorescence spectroscopy. Among these fluoroionophores, compound 4, having a sulfinyl group, showed high selectivity toward Li⁺.


Subject(s)
Fluorescent Dyes/chemical synthesis , Ion Transport/physiology , Ionophores/chemical synthesis , Lithium , Molecular Probes/chemical synthesis , Pyrenes/chemical synthesis , Benzene Derivatives , Binding Sites , Carbohydrate Conformation , Drug Design , Fluorescent Dyes/analysis , Ionophores/analysis , Ions/metabolism , Lithium/metabolism , Magnetic Resonance Spectroscopy , Molecular Probes/analysis , Pyrenes/analysis , Sensitivity and Specificity , Solvents/chemistry , Spectrometry, Fluorescence , Sulfones/chemistry
3.
Biosci Biotechnol Biochem ; 73(8): 1901-4, 2009 Aug.
Article in English | MEDLINE | ID: mdl-19661718

ABSTRACT

OsWRKY53, a chitin oligosaccharide elicitor-responsive rice WRKY gene, has been found to be involved in defense responses in rice. We identified three tandem W-box elements, putative recognition sites for WRKY transcription factors, as cis elements that are essential to the elicitor-responsiveness of OsWRKY53 by deletion and mutation analysis of the promoter by dual luciferase assay.


Subject(s)
Oryza/genetics , Oryza/physiology , Plant Proteins/genetics , Promoter Regions, Genetic/genetics , Transcription Factors/genetics , Base Sequence , Cells, Cultured , Chitin/metabolism , Luciferases/genetics , Plant Proteins/metabolism , Response Elements , Sequence Deletion , Transcription Factors/metabolism
4.
Biosci Biotechnol Biochem ; 72(12): 3237-48, 2008 Dec.
Article in English | MEDLINE | ID: mdl-19060398

ABSTRACT

Carbazole 1,9a-dioxygenase (CARDO) consists of terminal oxygenase (CARDO-O) and electron transport components. CARDO can catalyze specific oxygenation for various substrates: angular dioxygenation for carbazole and dibenzo-p-dioxin, lateral dioxygenation for anthracene, and monooxygenation for methylene carbon of fluorene and sulfide sulfur of dibenzothiophene. To elucidate the molecular mechanism determining its unique substrate specificity, 17 CARDO-O site-directed mutants at amino acid residues I262, F275, Q282, and F329, which form the substrate-interacting wall around the iron active site by CARDO-O crystal structure, were generated and characterized. F329 replacement dramatically reduced oxygenation activity. However, several mutants produced different products from the wild-type enzyme to a large extent: I262V and Q282Y (1-hydroxycarbazole), F275W (4-hydroxyfluorene), F275A (unidentified cis-dihydrodiol of fluoranthene), and I262A and I262W (monohydroxydibenzothiophenes). These results suggest the possibility that the respective substrates bind to the active sites of CARDO-O mutants in a different orientation from that of the wild-type enzyme.


Subject(s)
Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Dioxygenases/chemistry , Dioxygenases/metabolism , Anthracenes/metabolism , Bacterial Proteins/genetics , Carbazoles/metabolism , Catalytic Domain , Dioxins/metabolism , Dioxygenases/genetics , Escherichia coli/cytology , Escherichia coli/metabolism , Fluorenes/metabolism , Models, Molecular , Mutagenesis, Site-Directed , Mutation , Oxidation-Reduction , Protein Conformation , Substrate Specificity , Thiophenes/metabolism
5.
Appl Microbiol Biotechnol ; 80(3): 485-97, 2008 Sep.
Article in English | MEDLINE | ID: mdl-18592232

ABSTRACT

In artificial environmental samples, the behavior of the IncP-7 conjugative plasmid pCAR1, which is involved in the catabolism of carbazole, was monitored. Sterile soil and water samples supplemented with carbazole were prepared. After inoculation with Pseudomonas putida harboring pCAR1, seven species of the genus Pseudomonas, and three other bacterial species, were monitored for carbazole degradation, bacterial survival, and conjugative transfer of pCAR1. In artificial soils, more than 90% of the carbazole was degraded in samples with high water content, suggesting that the water content is a key factor in carbazole degradation in artificial soils. In three of the artificial environmental water samples, more than 95% of the carbazole was degraded. Transconjugants were detected in some artificial water samples, but not in the artificial soil samples, suggesting that pCAR1 is preferably transferred in aqueous environments. Composition analysis of the artificial water samples and examination of conjugative transfer indicated that the presence of the divalent cations Ca(2+) and Mg(2+) promoted the plasmid transfer. The presence of carbazole also increases in incidence of transconjugants, probably by enhancing their growth. In contrast, humic acids in the liquid layer of artificial soil samples appeared to prevent conjugative transfer.


Subject(s)
Carbazoles/metabolism , Plasmids/metabolism , Soil Pollutants/metabolism , Soil/analysis , Water Pollutants/metabolism , Bacteria/genetics , Bacteria/growth & development , Biodegradation, Environmental , Conjugation, Genetic , Plasmids/genetics , Pseudomonas putida/genetics , Pseudomonas putida/metabolism , Soil Microbiology , Water Microbiology
6.
Appl Environ Microbiol ; 72(5): 3198-205, 2006 May.
Article in English | MEDLINE | ID: mdl-16672458

ABSTRACT

The carbazole degradative car-I gene cluster (carAaIBaIBbICIAcI) of Sphingomonas sp. strain KA1 is located on the 254-kb circular plasmid pCAR3. Carbazole conversion to anthranilate is catalyzed by carbazole 1,9a-dioxygenase (CARDO; CarAaIAcI), meta-cleavage enzyme (CarBaIBbI), and hydrolase (CarCI). CARDO is a three-component dioxygenase, and CarAaI and CarAcI are its terminal oxygenase and ferredoxin components. The car-I gene cluster lacks the gene encoding the ferredoxin reductase component of CARDO. In the present study, based on the draft sequence of pCAR3, we found multiple carbazole degradation genes dispersed in four loci on pCAR3, including a second copy of the car gene cluster (carAaIIBaIIBbIICIIAcII) and the ferredoxin/reductase genes fdxI-fdrI and fdrII. Biotransformation experiments showed that FdrI (or FdrII) could drive the electron transfer chain from NAD(P)H to CarAaI (or CarAaII) with the aid of ferredoxin (CarAcI, CarAcII, or FdxI). Because this electron transfer chain showed phylogenetic relatedness to that consisting of putidaredoxin and putidaredoxin reductase of the P450cam monooxygenase system of Pseudomonas putida, CARDO systems of KA1 can be classified in the class IIA Rieske non-heme iron oxygenase system. Reverse transcription-PCR (RT-PCR) and quantitative RT-PCR analyses revealed that two car gene clusters constituted operons, and their expression was induced when KA1 was exposed to carbazole, although the fdxI-fdrI and fdrII genes were expressed constitutively. Both terminal oxygenases of KA1 showed roughly the same substrate specificity as that from the well-characterized carbazole degrader Pseudomonas resinovorans CA10, although slight differences were observed.


Subject(s)
Bacterial Proteins/genetics , Carbazoles/metabolism , Multigene Family , Plasmids/genetics , Sphingomonas/enzymology , Sphingomonas/genetics , ortho-Aminobenzoates/metabolism , Bacterial Proteins/chemistry , Bacterial Proteins/metabolism , Dioxygenases/genetics , Dioxygenases/metabolism , Ferredoxins/genetics , Ferredoxins/metabolism , Molecular Sequence Data , Oxygenases/genetics , Oxygenases/metabolism , Sequence Analysis, DNA
7.
Microbiology (Reading) ; 151(Pt 11): 3713-3722, 2005 Nov.
Article in English | MEDLINE | ID: mdl-16272392

ABSTRACT

Terrabacter sp. strain DBF63 is capable of degrading fluorene (FN) to tricarboxylic acid cycle intermediates via phthalate and protocatechuate. Genes were identified for the protocatechuate branch of the beta-ketoadipate pathway (pcaR, pcaHGBDCFIJ) by sequence analysis of a 70 kb DNA region of the FN-catabolic linear plasmid pDBF1. RT-PCR analysis of RNA from DBF63 cells grown with FN, dibenzofuran, and protocatechuate indicated that the pcaHGBDCFIJ operon was expressed during both FN and protocatechuate degradation in strain DBF63. The gene encoding beta-ketoadipate enol-lactone hydrolase (pcaD) was not fused to the next gene, which encodes gamma-carboxymuconolactone decarboxylase (pcaC), in strain DBF63, even though the presence of the pcaL gene (the fusion of pcaD and pcaC) within a pca gene cluster has been thought to be a Gram-positive trait. Quantitative RT-PCR analysis revealed that pcaD mRNA levels increased sharply in response to protocatechuate, and a biotransformation experiment with cis,cis-muconate using Escherichia coli carrying both catBC and pcaD indicated that PcaD exhibited beta-ketoadipate enol-lactone hydrolase activity. The location of the pca gene cluster on the linear plasmid, and the insertion sequences around the pca gene cluster suggest that the ecologically important beta-ketoadipate pathway genes, usually located chromosomally, may be spread widely among bacterial species via horizontal transfer or transposition events.


Subject(s)
Actinomycetales/genetics , Adipates/metabolism , Bacterial Proteins/genetics , Fluorenes/metabolism , Hydroxybenzoates/metabolism , Plasmids/genetics , Actinomycetales/metabolism , Bacterial Proteins/metabolism , Carboxylic Ester Hydrolases/genetics , Carboxylic Ester Hydrolases/metabolism , Gene Expression Regulation, Bacterial , Molecular Sequence Data , Multigene Family , Proteobacteria/genetics , Proteobacteria/metabolism , Sequence Analysis, DNA
8.
J Biosci Bioeng ; 98(4): 306-8, 2004.
Article in English | MEDLINE | ID: mdl-16233711

ABSTRACT

Alkaliphilic Mycobacterium sp. strain MHP-1, which can grow on pyrene as a sole carbon and energy source, was isolated from a soil sample. At the optimum pH for growth (pH 9), about 50% of pyrene (final concentration at 0.1% [w/v]) was degraded during 7 d of incubation, and 4,5-phenanthrenedioic acid, 4-phenanthroic acid and phthalic acid were identified as metabolic intermediates. Strain MHP-1 was found to possess aromatic-ring dioxygenase genes, which are highly homologous to the known nidAB genes from pyrene-degrading mycobacteria.

9.
Biochem Biophys Res Commun ; 296(2): 233-40, 2002 Aug 16.
Article in English | MEDLINE | ID: mdl-12163007

ABSTRACT

Reverse transcription-PCR of the dbfA1A2, dbfBC, and pht genes, encoding oxygenase component of multicomponent dioxygenase, meta cleavage enzyme and hydrolase, and phthalate-degrading enzymes, respectively, revealed their role in the aromatic compound degradation by Terrabacter sp. strain DBF63. The specific expression in strain DBF63 cells grown on dibenzofuran (the model compound of dioxin; DF) and/or fluorene (FN) indicated that the DbfA1A2 and DbfBC catalyze the conversion of DF to salicylate, and that the DbfA1A2 and Pht enzymes are involved in FN degradation. Pulsed-field gel electrophoresis analyses revealed that the dbfA1A2 cistron and pht operon were located on the two linear plasmids, pDBF1 (160 kb) and pDBF2 (190 kb), while dbfBC genes were located on the chromosome. Because the pht operon is located immediately upstream of the dbfA1A2 cistron, the dioxin-catabolic genes were dispersed on the genome of strain DBF63, while FN-catabolic genes were gathered on the plasmids.


Subject(s)
Actinomycetales/enzymology , Bacterial Proteins/metabolism , Dioxins/metabolism , Genes, Bacterial , Oxygenases/metabolism , Actinomycetales/genetics , Bacterial Proteins/genetics , Benzofurans/metabolism , Biodegradation, Environmental , Carcinogens/metabolism , Fluorenes/metabolism , Molecular Structure , Open Reading Frames , Oxygenases/genetics , Phthalic Acids/metabolism , Soil Microbiology
10.
Nihon Hoshasen Gijutsu Gakkai Zasshi ; 58(9): 1245-51, 2002 Sep.
Article in English | MEDLINE | ID: mdl-12520220

ABSTRACT

Although contrast media are indispensable for x-ray diagnosis, they are xenobiotics and may cause undesirable adverse reactions. We have correlated several allergies to the adverse reactions caused by three representative contrast media in order to predict and prevent possible problems. The adverse reactions were observed at probabilities of up to 100%(odds ratio 8.0) in drug allergy and contact dermatitis patients. These allergies were proven in this study to be type IV reactions, and all the observed adverse reactions were classified as allergies of either type I or IV. Thus, one can predict to some extent even the time when the adverse reaction will appear after the injection of contrast medium. Finally, a questionnaire to be administered prior to contrast enhanced CT examinations has been proposed. The questionnaire is designed to predict adverse reactions on the basis of statistical analysis. Since the physicochemical properties of contrast media are different, this questionnaire is also useful for selecting the most suitable contrast medium for the patient.


Subject(s)
Contrast Media/adverse effects , Drug Hypersensitivity/epidemiology , Iohexol/analogs & derivatives , Iohexol/adverse effects , Ioxaglic Acid/adverse effects , Tomography, X-Ray Computed , Drug Hypersensitivity/prevention & control , Forecasting , Humans , Odds Ratio , Radiographic Image Enhancement , Surveys and Questionnaires , Time Factors
SELECTION OF CITATIONS
SEARCH DETAIL
...