Ralstonia pickettii

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Yoshio Inoue - One of the best experts on this subject based on the ideXlab platform.

Catherine C Adley - One of the best experts on this subject based on the ideXlab platform.

  • The antibiotic susceptibility of water-based bacteria Ralstonia pickettii and Ralstonia insidiosa.
    Journal of Medical Microbiology, 2013
    Co-Authors: Michael P. Ryan, Catherine C Adley
    Abstract:

    Ralstonia pickettii and Ralstonia insidiosa are waterborne bacteria that can survive and grow in various water sources, and that are emerging pathogens in hospital settings. Not much is known about the antibiotic resistance of these bacteria. Previous reports of antimicrobial susceptibility have been largely limited to a few clinical strains with no accounting for genotypic or phenotypic diversity or that these species could vary from the set breakpoints. Etests and disc diffusion tests were carried out to compare the antimicrobial susceptibilities to 12 different antibiotics of 68 different isolates of R. pickettii (53) and R. insidiosa (15) from varying environments, which have previously been well characterized both phenotypically and genetically. The majority of the R. pickettii and R. insidiosa isolates showed susceptibility to most of the antibiotics tested in this study. The most effective were found to be the quinolones and sulfamethoxazole/trimethoprim. Antibiotic susceptibility was also found not to vary between environmental niches for R. pickettii and R. insidiosa isolates.

  • genotypic and phenotypic diversity of Ralstonia pickettii and Ralstonia insidiosa isolates from clinical and environmental sources including high purity water diversity in Ralstonia pickettii
    BMC Microbiology, 2011
    Co-Authors: Michael P. Ryan, Tony J Pembroke, Catherine C Adley
    Abstract:

    Background: Ralstonia pickettii is a nosocomial infectious agent and a significant industrial contaminant. It has been found in many different environments including clinical situations, soil and industrial High Purity Water. This study compares the phenotypic and genotypic diversity of a selection of strains of Ralstonia collected from a variety of sources. Results: Ralstonia isolates (fifty-nine) from clinical, industrial and environmental origins were compared genotypically using i) Species-specific-PCR, ii) PCR and sequencing of the 16S-23S rRNA Interspatial region (ISR) iii) the fliC gene genes, iv) RAPD and BOX-PCR and v) phenotypically using biochemical testing. The species specificPCR identified fifteen out of fifty-nine designated R. pickettii isolates as actually being the closely related species R. insidiosa. PCR-ribotyping of the 16S-23S rRNA ISR indicated few major differences between the isolates. Analysis of all isolates demonstrated different banding patterns for both the RAPD and BOX primers however these were found not to vary significantly. Conclusions: R. pickettii species isolated from wide geographic and environmental sources appear to be reasonably homogenous based on genotypic and phenotypic characteristics. R. insidiosa can at present only be distinguished from R. pickettii using species specific PCR. R. pickettii and R. insidiosa isolates do not differ significantly phenotypically or genotypically based on environmental or geographical origin.

  • Differentiating the growing nosocomial infectious threats Ralstonia pickettii and Ralstonia insidiosa
    European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology, 2011
    Co-Authors: Michael P. Ryan, J.t. Pembroke, Catherine C Adley
    Abstract:

    Differentiation of the growing nosocomial infectious threats, Ralstonia pickettii and Ralstonia insidiosa, based on nitrate reduction, desferrioxamine susceptibility, arabinose, N-acetyl-glucosamine and phenylacetate assimilation is described. These tests can be used for preliminary identification of Ralstonia pickettii and Ralstonia insidiosa resulting in more accurate identification of these species.

  • Novel Tn4371-ICE like element in Ralstonia pickettii and Genome mining for comparative elements
    BMC microbiology, 2009
    Co-Authors: Michael P. Ryan, J.t. Pembroke, Catherine C Adley
    Abstract:

    Background Integrative Conjugative Elements (ICEs) are important factors in the plasticity of microbial genomes. An element related to the ICE Tn4371 was discovered during a bioinformatic search of the Ralstonia pickettii 12J genome. This element was analysed and further searches carried out for additional elements. A PCR method was designed to detect and characterise new elements of this type based on this scaffold and a culture collection of fifty-eight Ralstonia pickettii and Ralstonia insidiosa strains were analysed for the presence of the element.

  • Ralstonia pickettii in environmental biotechnology potential and applications
    Journal of Applied Microbiology, 2007
    Co-Authors: Michael P. Ryan, J.t. Pembroke, Catherine C Adley
    Abstract:

    Xenobiotic pollutants such as toluene and trichloroethylene are released into the environment by various industrial processes. Ralstonia pickettii possess significant biotechnological potential in the field of bioremediation and has demonstrated the ability to breakdown many of these toxic substances. Here, we provide a description of the major compounds that various strains of R. pickettii are capable of degrading and a brief review of their breakdown pathways and an argument for its use in bioremediation.

Yoshiharu Doi - One of the best experts on this subject based on the ideXlab platform.

  • Adsorption and hydrolysis reactions of poly(hydroxybutyric acid) depolymerases secreted from Ralstonia pickettii T1 and Penicillium funiculosum onto poly[(R)-3-hydroxybutyric acid].
    Biomacromolecules, 2007
    Co-Authors: Keiji Numata, Koichi Yamashita, Masahiro Fujita, Takeharu Tsuge, Ken-ichi Kasuya, Tadahisa Iwata, Yoshiharu Doi, Hideki Abe
    Abstract:

    Reaction processes of poly[(R)-3-hydroxybutyric acid] (P(3HB)) with two types of poly(hydroxybutyric acid) (PHB) depolymerases secreted from Ralstonia pickettii T1 and Penicillium funiculosum were characterized by means of atomic force microscopy (AFM) and quartz crystal microbalance (QCM). The PHB depolymerase from R. pickettii T1 consists of catalytic, linker, and substrate-binding domains, whereas the one from P. funiculosum lacks a substrate-binding domain. We succeeded in observing the adsorption of single molecules of the PHB depolymerase from R. pickettii T1 onto P(3HB) single crystals and the degradation of the single crystals in a phosphate buffer solution at 37 °C by real-time AFM. On the contrary, the enzyme molecule from P. funiculosum was hardly observed at the surface of P(3HB) single crystals by real-time AFM, even though the enzymatic degradation of the single crystals was surely progressed. On the basis of the AFM observations in air of the P(3HB) single crystals after the enzymatic treat...

  • effects of mutations in the substrate binding domain of poly r 3 hydroxybutyrate phb depolymerase from Ralstonia pickettii t1 on phb degradation
    Applied and Environmental Microbiology, 2006
    Co-Authors: Tomohiro Hiraishi, Yoshiharu Doi, Mizuo Maeda, Yoko Hirahara, Seiichi Taguchi
    Abstract:

    Poly[(R)-3-hydroxybutyrate] (PHB) depolymerase from Ralstonia pickettii T1 (PhaZRpiT1) adsorbs to denatured PHB (dPHB) via its substrate-binding domain (SBD) to enhance dPHB degradation. To evaluate the amino acid residues participating in dPHB adsorption, PhaZRpiT1 was subjected to a high-throughput screening system consisting of PCR-mediated random mutagenesis targeted to the SBD gene and a plate assay to estimate the effects of mutations in the SBD on dPHB degradation by PhaZRpiT1. Genetic analysis of the isolated mutants with lowered activity showed that Ser, Tyr, Val, Ala, and Leu residues in the SBD were replaced by other residues at high frequency. Some of the mutant enzymes, which contained the residues replaced at high frequency, were applied to assays of dPHB degradation and adsorption, revealing that those residues are essential for full activity of both dPHB degradation and adsorption. These results suggested that PhaZRpiT1 adsorbs on the surface of dPHB not only via hydrogen bonds between hydroxyl groups of Ser in the enzyme and carbonyl groups in the PHB polymer but also via hydrophobic interaction between hydrophobic residues in the enzyme and methyl groups in the PHB polymer. The L441H enzyme, which displayed lower dPHB degradation and adsorption abilities, was purified and applied to a dPHB degradation assay to compare it with the wild-type enzyme. The kinetic analysis of the dPHB degradation suggested that lowering the affinity of the SBD towards dPHB causes a decrease in the dPHB degradation rate without the loss of its hydrolytic activity for the polymer chain.

  • Enzymatic Hydrolysis of Thioester Linkages in Bacterial Poly(3-hydroxybutyrate-co-3-mercaptopropionate)s by Poly(3-hydroxybutyrate) Depolymerase Isolated from Ralstonia pickettii T1
    Polymer Journal, 2005
    Co-Authors: Bo Zhu, Ken-ichi Kasuya, Yoshiharu Doi, Shogo Tanaka, Lidan Feng, Nariaki Ishii, Yoshio Inoue
    Abstract:

    Enzymatic Hydrolysis of Thioester Linkages in Bacterial Poly(3-hydroxybutyrate- co -3-mercaptopropionate)s by Poly(3-hydroxybutyrate) Depolymerase Isolated from Ralstonia pickettii T1

  • enzymatic degradation behavior of comonomer compositionally fractionated bacterial poly 3 hydroxybutyrate co 3 hydroxyvalerate s by poly 3 hydroxyalkanoate depolymerases isolated from Ralstonia pickettii t1 and acidovorax sp tp4
    Polymer Degradation and Stability, 2004
    Co-Authors: Lidan Feng, Terumi Saito, Ken-ichi Kasuya, Yoshiharu Doi, Yi Wang, Yasuhide Inagawa, Yoshio Inoue
    Abstract:

    Abstract The enzymatic hydrolysis behavior of compositionally well-fractionated bacterial poly(3-hydroxybutyrate- co -3-hydroxyvalerate) [P(3HB- co -3HV)] with 3HV-unit content from 8 to 98 mol% and bacterial poly(3-hydroxybutyrate) [P(3HB)] has been investigated in the presence of poly(3-hydroxyalkanoate) depolymerases isolated from Ralstonia pickettii T1 and Acidovorax sp. TP4. The water-soluble degradation products were characterized by HPLC and 1 H NMR spectroscopy. P(3HB- co -3HV)s with the whole range of 3HV-unit content can be degraded by R. pickettii T1 depolymerase, while only P(3HB- co -3HV)s with 3HV-unit content less than 80 mol% can be degraded by Acidovorax sp. TP4 depolymerase. It was found that the enzymatic degradation behavior of fractionated P(3HB- co -3HV)s was affected not only by the comonomer unit composition and its distribution but also by the solid-state structure of P(3HB- co -3HV)s and further by the bacterial source of depolymerases. Based on the results, the mechanism of enzymatic degradation was discussed.

  • enzymatic hydrolysis of chemosynthesized atactic poly 3 hydroxybutyrate by poly 3 hydroxyalkanoate depolymerase from acidovorax sp tp4 and Ralstonia pickettii t1
    Biomacromolecules, 2002
    Co-Authors: Yi Wang, Terumi Saito, Ken-ichi Kasuya, Yoshiharu Doi, Yasuhide Inagawa, Yasushi Osanai, Shuichi Matsumura, Yoshio Inoue
    Abstract:

    The enzymatic degradability of chemosynthesized atactic poly([R,S]-3-hydroxybutyrate) [a-P(3HB)] by two types of extracellular poly(3-hydroxyalkanoate) (PHA) depolymerases purified from Ralstonia pickettii T1 (PhaZ(ral)) and Acidovorax Sp. TP4 (PhaZ(aci)), defined respectively as PHA depolymerase types I and II according to the position of the lipase box in the catalytic domain, were studied. The enzymatic degradation of a-P(3HB) by PhaZ(aci) depolymerase was confirmed from the results of weight loss and the scanning electron micrographs. The degradation products were characterized by one- and two-dimension (1)H NMR spectroscopy. It was found that a-P(3HB) could be degraded into monomer, dimer, and trimer by PhaZ(aci) depolymerase at temperatures ranging from 4 to 20 degrees C, while a-P(3HB) could hardly be hydrolyzed by PhaZ(ral) depolymerase in the same temperature range. These results suggested that the chemosynthesized a-P(3HB) could be degraded in the pure state by natural PHA depolymerase.

Thomas K Wood - One of the best experts on this subject based on the ideXlab platform.

  • physiological relevance of successive hydroxylations of toluene by toluene para monooxygenase of Ralstonia pickettii pko1
    Biocatalysis and Biotransformation, 2004
    Co-Authors: Ayelet Fishman, Ying Tao, Thomas K Wood
    Abstract:

    We have recently found that toluene para-monooxygenase (TpMO) of Ralstonia pickettii PKO1 (encoded by tbuA1UBVA2C) performs successive hydroxylations of benzene (Appl. Environ. Microbiol. 70: 3814, 2004) as well as hydroxylates toluene to a mixture of 90% p-cresol and 10% m-cresol which are then further oxidized to 100% 4-methylcatechol (J. Bacteriol. 186: 3117, 2004) whereas it was thought previously that TpMO forms 100% m-cresol and is not capable of successive hydroxylations. Here we propose a modification of the degradation pathway originally described by Olsen et al. (J. Bacteriol. 176: 3749, 1994) that now relies primarily on TpMO for conversion of toluene to 4-methylcatechol (instead of m-cresol) since both m-cresol and p-cresol are shown here to be good substrates for Escherichia coli expressing TpMO (Vmax/Km=0.046, 0.036, and 0.055 mL min−1 mg−1 protein for the oxidation of toluene, m-cresol, and p-cresol, respectively). In light of the broader activity of TpMO, phenol hydroxylase (encoded by tbu...

  • oxidation of benzene to phenol catechol and 1 2 3 trihydroxybenzene by toluene 4 monooxygenase of pseudomonas mendocina kr1 and toluene 3 monooxygenase of Ralstonia pickettii pko1
    Applied and Environmental Microbiology, 2004
    Co-Authors: Ying Tao, Ayelet Fishman, William E Bentley, Thomas K Wood
    Abstract:

    Aromatic hydroxylations are important bacterial metabolic processes but are difficult to perform using traditional chemical synthesis, so to use a biological catalyst to convert the priority pollutant benzene into industrially relevant intermediates, benzene oxidation was investigated. It was discovered that toluene 4-monooxygenase (T4MO) of Pseudomonas mendocina KR1, toluene 3-monooxygenase (T3MO) of Ralstonia pickettii PKO1, and toluene ortho-monooxygenase (TOM) of Burkholderia cepacia G4 convert benzene to phenol, catechol, and 1,2,3-trihydroxybenzene by successive hydroxylations. At a concentration of 165 μM and under the control of a constitutive lac promoter, Escherichia coli TG1/pBS(Kan)T4MO expressing T4MO formed phenol from benzene at 19 ± 1.6 nmol/min/mg of protein, catechol from phenol at 13.6 ± 0.3 nmol/min/mg of protein, and 1,2,3-trihydroxybenzene from catechol at 2.5 ± 0.5nmol/min/mg of protein. The catechol and 1,2,3-trihydroxybenzene products were identified by both high-pressure liquid chromatography and mass spectrometry. When analogous plasmid constructs were used, E. coli TG1/pBS(Kan)T3MO expressing T3MO formed phenol, catechol, and 1,2,3-trihydroxybenzene at rates of 3 ± 1, 3.1 ± 0.3, and 0.26 ± 0.09 nmol/min/mg of protein, respectively, and E. coli TG1/pBS(Kan)TOM expressing TOM formed 1,2,3-trihydroxybenzene at a rate of 1.7 ± 0.3 nmol/min/mg of protein (phenol and catechol formation rates were 0.89 ± 0.07 and 1.5 ± 0.3 nmol/min/mg of protein, respectively). Hence, the rates of synthesis of catechol by both T3MO and T4MO and the 1,2,3-trihydroxybenzene formation rate by TOM were found to be comparable to the rates of oxidation of the natural substrate toluene for these enzymes (10.0 ± 0.8, 4.0 ± 0.6, and 2.4 ± 0.3 nmol/min/mg of protein for T4MO, T3MO, and TOM, respectively, at a toluene concentration of 165 μM).

  • Toluene 3-monooxygenase of Ralstonia pickettii PKO1 is a para-hydroxylating enzyme
    2004
    Co-Authors: Ayelet Fishman, Ying Tao, Thomas K Wood
    Abstract:

    Oxygenases are promising biocatalysts for performing selective hydroxylations not accessible by chemical methods. Whereas toluene 4-monooxygenase (T4MO) of Pseudomonas mendocina KR1 hydroxylates monosub-stituted benzenes at the para position and toluene ortho-monooxygenase (TOM) of Burkholderia cepacia G4 hydroxylates at the ortho position, toluene 3-monooxygenase (T3MO) of Ralstonia pickettii PKO1 was reported previously to hydroxylate toluene at the meta position, producing primarily m-cresol (R. H. Olsen, J. J. Kukor, and B. Kaphammer, J. Bacteriol. 176:3749-3756, 1994). Using gas chromatography, we have discovered that T3MO hydroxylates monosubstituted benzenes predominantly at the para position. TG1/pBS(Kan)T3MO cells expressing T3MO oxidized toluene at a maximal rate of 11.5 0.33 nmol/min/mg of protein with an apparent Km value of 250 M and produced 90 % p-cresol and 10 % m-cresol. This product mixture was successively transformed to 4-methylcatechol. T4MO, in comparison, produces 97 % p-cresol and 3 % m-cresol. Pseudomonas aeruginosa PAO1 harboring pRO1966 (the original T3MO-bearing plasmid) also exhibited the same product distribution as that of TG1/pBS(Kan)T3MO. TG1/pBS(Kan)T3MO produced 66 % p-nitrophenol and 34% m-nitrophenol from nitrobenzene and 100 % p-methoxyphenol from methoxybenzene, as well as 62 % 1-naphthol and 38 % 2-naphthol from naphthalene; similar results were found with TG1/pBS(Kan)T4MO. Sequencing of the tbu locus from pBS(Kan)T3MO and pRO1966 revealed complete identity between the two, thus eliminatin

Ken-ichi Kasuya - One of the best experts on this subject based on the ideXlab platform.