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Journal of General Microbiology Jul 1981Spontaneous alginate-producing (muc) variants were isolated from strains of Pseudomonas fluorescens, P. putida and P. mendocina at a frequency of 1 in 10(8) by selecting...
Spontaneous alginate-producing (muc) variants were isolated from strains of Pseudomonas fluorescens, P. putida and P. mendocina at a frequency of 1 in 10(8) by selecting for carbenicillin resistance. The infrared spectrum of the bacterial exopolysaccharide was typical of an acetylated alginate similar to that previously described in Azotobacter vinelandii and in mucoid variants of P. aeruginosa. Mucoid variants were not isolated from P. stutzeri, P. pseudoalcaligenes, P. testosteroni, P. diminuta, P. acidovorans, P. cepacia or P. maltophilia.
Topics: Alginates; Glucuronic Acid; Hexuronic Acids; Mutation; Pseudomonas; Pseudomonas fluorescens
PubMed: 6801192
DOI: 10.1099/00221287-125-1-217 -
International Journal of Biological... May 2020Alginate is a family of industrially important linear polymers consisting of β-D-mannuronic acid (M) and its C-5 epimer α-L-guluronic acid (G). The function of...
Alginate is a family of industrially important linear polymers consisting of β-D-mannuronic acid (M) and its C-5 epimer α-L-guluronic acid (G). The function of alginate is closely related to the ratio of M/G. Mannuronan C-5 epimerase, which converts M to G, is a key enzyme involved in the biosynthesis of alginate. A new mannuronan C-5 epimerase isolated from Pseudomonas mendocina. sp. DICP-70 named PmC5A was characterized in this study. From the H NMR analysis of the products, we have found that PmC5A possesses alginate lyase function in addition to mannuronan C-5-epimerase. The optimal pH and temperature of lyase and epimerase were found to be 8.0, 9.0 and 40 °C, 30 °C, respectively. PmC5A also shows lyase activity toward PolyMG and G-blocks.
Topics: Alginates; Bacterial Proteins; Carbohydrate Epimerases; Nuclear Magnetic Resonance, Biomolecular; Polysaccharide-Lyases; Pseudomonas mendocina
PubMed: 32061850
DOI: 10.1016/j.ijbiomac.2020.02.126 -
Microbiological Research May 2013The medium-chain-length polyhydroxyalkanoate (PHAMCL) synthase genes phaC1 and phaC2 of Pseudomonas mendocina NK-01 were cloned and inserted into expression plasmid... (Comparative Study)
Comparative Study
The medium-chain-length polyhydroxyalkanoate (PHAMCL) synthase genes phaC1 and phaC2 of Pseudomonas mendocina NK-01 were cloned and inserted into expression plasmid pBBR1MCS-2 to form pBBR1MCS-C1 and pBBR1MCS-C2 which were expressed respectively in the PHAMCL-negative strain P. mendocina C7 whose PHAMCL synthesis operon was defined knock out. P. mendocina C7 derivatives P. mendocina C7C1 and C7C2 carrying pBBR1MCS-C1 and pBBR1MCS-C2 respectively were constructed. Fermentation and gel permeation chromatography (GPC) revealed that P. mendocina C7C1 had higher PHAMCL production rate but its PHAMCL had lower molecular weight than that of P. mendocina C7C2. Gas chromatograph/mass spectrometry (GC/MS) analysis revealed that the two PHAMCL had similarity in monomer composition with 3HD as the favorite monomer i.e. PhaC1 and PhaC2 had the same substrate specificity. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and X-ray diffraction (XRD) also revealed that the two PHAMCL had the same physical properties. P. mendocina NK-01was the first reported strain whose PHAMCL synthases PhaC1 and PhaC2 had the same substrate specificity.
Topics: Acyltransferases; Amino Acid Sequence; Bacterial Proteins; Molecular Sequence Data; Polyhydroxyalkanoates; Pseudomonas mendocina; Sequence Alignment; Substrate Specificity
PubMed: 23238264
DOI: 10.1016/j.micres.2012.11.003 -
Environmental Science and Pollution... Oct 2020Lipase enzyme has a critical role in deinking process along with other lignocellulosic enzymes. In this paper, we try to demonstrate the role of lipase in the enzyme...
Lipase enzyme has a critical role in deinking process along with other lignocellulosic enzymes. In this paper, we try to demonstrate the role of lipase in the enzyme cocktail used for enzymatic deinking. For this, we identified a potential lipolytic bacterium, Pseudomonas mendocina ED9 isolated from elephant dung with a molecular weight of 35 kDa. During the Box-Benhken model optimization, a maximum lipase activity of 105.12 U/g, which was 12.36-fold higher than the initial enzyme activity and 1.3-fold higher than the activity obtained during the Plackett Burman design, was achieved. A maximum lipase activity of 105.12 U/g was obtained after optimization. Ammonium sulphate (60%) precipitation resulted in a specific activity of 68.19 U/mg with a 1.4-fold purification and yield of 64%. Lipase from P. mendocina ED9 exhibited a Km of 0.5306 mM and Vmax of 25.0237 μmol/min/mg. A Δ brightness of approximately 14.5% were achieved during the enzymatic deinking using cocktail comprised of cellulase, xylanase and lipase. This reports the significant role and efficacy of lipase in enzyme cocktails for deinking applications. This formulation will reduce the pollution and environmental toxicity of conventional chemical deinking.
Topics: Cellulase; Hydrogen-Ion Concentration; Ink; Lipase; Paper; Pseudomonas mendocina
PubMed: 32562224
DOI: 10.1007/s11356-020-09641-z -
Journal of Microbiological Methods Jun 2015A markerless gene replacement method was adapted by combining a suicide plasmid, pEX18Tc, with a counterselectable marker, the upp gene encoding uracil...
A markerless gene replacement method was adapted by combining a suicide plasmid, pEX18Tc, with a counterselectable marker, the upp gene encoding uracil phosphoribosyltransferase (UPRTase), for the medium-chain length polyhydroxyalkanoates (PHA(MCL))-producing strain Pseudomonas mendocina NK-01. An NK-01 5-fluorouracil (5-FU) resistant background strain was first constructed by deleting the chromosomal upp gene. The suicide plasmid pEX18Tc, carrying a functional allele of the upp gene of P. mendocina NK-01, was used to construct the vectors to delete the algA (encoding mannose-1-phosphate guanylyltransferase) and phaZ (encoding PHA(MCL) depolymerase) genes, and a 30 kb chromosomal fragment in the 5-FU resistant background host. The genes were removed efficiently from the genome of P. mendocina NK-01 and left a markerless chromosomal mutant. In addition, two exogenous genes were inserted into the phaC1 (PHA(MCL) polymerase) loci of Pseudomonas putida KT-∆UPP simultaneously. Thus, we constructed a genetically stable and marker-free P. putida KT2440 mutant with integrated mpd (encoding methyl parathion hydrolase (MPH)) and pytH (encoding a pyrethroid-hydrolyzing carboxylesterase (PytH)) gene on the chromosome. The upp-based counterselection system could be further adapted for P. mendocina NK-01 and P. putida KT2440 and used for genome reduction and metabolic pathway engineering.
Topics: Carboxylesterase; Chromosome Deletion; Fluorouracil; Genetic Vectors; Genome, Bacterial; Metabolic Engineering; Metabolic Networks and Pathways; Mutation; Pentosyltransferases; Phosphoric Monoester Hydrolases; Plasmids; Pseudomonas mendocina; Pseudomonas putida; Pyrethrins
PubMed: 25828098
DOI: 10.1016/j.mimet.2015.03.022 -
Biotechnology and Applied Biochemistry 2015We optimized the culture medium for 3-hydroxycarboxylic acid production by Pseudomonas mendocina DS-04-T-biodegraded polyhydroxybutyrate (PHB) using the Plackett-Burman...
We optimized the culture medium for 3-hydroxycarboxylic acid production by Pseudomonas mendocina DS-04-T-biodegraded polyhydroxybutyrate (PHB) using the Plackett-Burman design, steepest ascent method, and Box-Behnken design. The optimized concentrations of the constituents of the culture medium were as follows: PHB (7.57 g/L), NH4 Cl (5.0 g/L), KH2 PO4 (2.64 g/L), Na2 HPO4 ·12H2 O (12 g/L), MgSO4 ·7H2 O (0.5 g/L), and CaCl2 ·2H2 O (5 mg/L). The yield of 3-hydroxycarboxylic acid obtained using the optimized culture medium was 56.8 ± 1.64%, which was 2.5-fold higher than that obtained when the unoptimized culture medium was used.
Topics: Biodegradable Plastics; Bioreactors; Carboxylic Acids; Culture Media; Hydroxybutyrates; Polyesters; Pseudomonas mendocina
PubMed: 24919602
DOI: 10.1002/bab.1257 -
Molecular Biotechnology Sep 2020Squalene hopene cyclases catalyse the conversion of a linear substrate squalene to a cyclic product with high stereo-selectivity.The enzyme squalene hopene cyclase from...
Squalene hopene cyclases catalyse the conversion of a linear substrate squalene to a cyclic product with high stereo-selectivity.The enzyme squalene hopene cyclase from Pseudomonas mendocina expressed in E. coli BL21 (DE3) was evaluated for its synthetic drug transforming ability. Nine synthetic drugs were selected as substrates for biotransformation reactions by the enzyme. The homology modelling of the protein and docking of the selected ligands were performed using GOLD suite docking software. The drug which showed maximum binding with the active-site residues of the enzyme was selected for biotransformation studies. On transformation with the enzyme, Glibenclamide, the selected antidiabetic drug alone showed significant changes in the FT/IR spectra; hence, it was selected for LCMS analysis to confirm the transformations. From the chromatogram and MS spectra, the mono-oxygenation of the product due to the enzymatic activity was confirmed. The drug transforming ability of the purified SHC could be used as an ideal tool for the generation of new and active substrate derivatives.
Topics: Bacterial Proteins; Escherichia coli; Glyburide; Intramolecular Transferases; Pseudomonas mendocina; Recombinant Proteins
PubMed: 32757148
DOI: 10.1007/s12033-020-00264-w -
Journal of Molecular Modeling Nov 2014The need of alkaline detergent-stable lipases has been growing rapidly as they are highly attractive for the production of detergents, biodiesel, pharmaceuticals agents,...
The need of alkaline detergent-stable lipases has been growing rapidly as they are highly attractive for the production of detergents, biodiesel, pharmaceuticals agents, and various other applications. Lipase from Pseudomonas mendocina (PML) is one such candidate with triglyceride activity and non-homologous with other reported Pseudomonas lipases. The present work provides insights on the role of amino acids toward structural stability of PML. PML was subjected to mutagenesis through in silico point mutations for emulating its structural stability, the foremost property to enhance biophysiochemical properties for industrial process. The structural effects of identified mutants on PML have been analyzed through comparative atomistic molecular dynamics simulations on wild type and mutants. The in silico mutants P187A and P219A were found to stabilize their respective local dynamics and improved the structural stability of PML. The current study sheds light on the rational engineering of PML through in silico methodologies to improvise its structural stability as well as prototype for rational engineering of the lipases.
Topics: Bacterial Proteins; Computational Biology; Enzyme Stability; Lipase; Molecular Dynamics Simulation; Mutagenesis, Site-Directed; Point Mutation; Protein Structure, Secondary; Pseudomonas mendocina; Reproducibility of Results; Structure-Activity Relationship
PubMed: 25367042
DOI: 10.1007/s00894-014-2501-4 -
Journal of Clinical Microbiology Jun 1992Pseudomonas mendocina has been isolated from soil and water samples. Although it has been recovered from some human clinical samples, its pathogenic role has not yet...
Pseudomonas mendocina has been isolated from soil and water samples. Although it has been recovered from some human clinical samples, its pathogenic role has not yet been documented. We report the first known case of endocarditis in humans due to P. mendocina.
Topics: Bacteremia; Endocarditis, Bacterial; Humans; Male; Middle Aged; Pseudomonas; Pseudomonas Infections
PubMed: 1624580
DOI: 10.1128/jcm.30.6.1583-1584.1992 -
Microbiology Spectrum Jun 2023Several variants of the plasmid-carried tigecycline resistance gene cluster, , have been identified. This study characterized another novel variant, , located on the...
Several variants of the plasmid-carried tigecycline resistance gene cluster, , have been identified. This study characterized another novel variant, , located on the chromosome of environmental-origin Pseudomonas mendocina. TMexC6D6-TOprJ1 mediates resistance to multiple drugs, including tigecycline. The promoter activity of and negative transcriptional repression by the upstream regulator tnfxB6 are crucial for the expression of . was found in the plasmids or chromosomes of different Pseudomonas species from six countries. Two genetic backgrounds, class 1 integrons and -carrying integrase units, were found adjacent to the gene cluster and might mediate the transfer of this novel efflux pump gene cluster in Pseudomonas. Further phylogenetic analysis revealed Pseudomonas as the major reservoir of variants, warranting closer monitoring in the future. Tigecycline is one of the treatment options for serious infections caused by multidrug-resistant bacteria, and tigecycline resistance has gained extensive attention. The emergence of a transferable tigecycline resistance efflux pump gene cluster, , severely challenged the efficiency of tigecycline. In this study, we identified another novel variant, , which could confer resistance to multiple classes of antibiotics, including tigecycline. Although was found only in Pseudomonas species, might spread to hosts via mobile genetic elements resembling those of other variants, compromising the therapeutic strategies. Meanwhile, novel transferable variants are constantly emerging and mostly exist in Pseudomonas spp., indicating Pseudomonas as the important hidden reservoir and origin of variants. Continuous monitoring and investigations of are urgent to control its spread.
Topics: Tigecycline; Pseudomonas; Phylogeny; Anti-Bacterial Agents; Plasmids; Microbial Sensitivity Tests
PubMed: 37067462
DOI: 10.1128/spectrum.00767-23