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Ecotoxicology and Environmental Safety Jan 2020Polycyclic aromatic hydrocarbons (PAH) contained in creosote oil are particularly difficult to remove from the soil environment. Their hydrophobic character and low...
Polycyclic aromatic hydrocarbons (PAH) contained in creosote oil are particularly difficult to remove from the soil environment. Their hydrophobic character and low bioavailability to soil microorganisms affects their rate of biodegradation. This study was performed on samples of soil that were (for over forty years) subjected to contamination with creosote oil, and their metagenome and physicochemical properties were characterized. Moreover, the study was undertaken to evaluate the biodegradation of PAHs by autochthonous consortia as well as by selected bacteria strains isolated from long-term contaminated industrial soil. From among the isolated microorganisms, the most effective in biodegrading the contaminants were the strains Pseudomonas mendocina and Brevundimonas olei. They were able to degrade more than 60% of the total content of PAHs during a 28-day test. The biodegradation of these compounds using AT7 dispersant was enhanced only by Serratia marcescens strain. Moreover, the addition of AT7 improved the effectiveness of fluorene and acenaphthene biodegradation by Serratia marcescens 6-fold. Our results indicated that long-term contact with aromatic compounds induced the bacterial strains to use the PAHs as a source of carbon and energy. We observed that supplementation with surfactants does not increase the efficiency of hydrocarbon biodegradation.
Topics: Biodegradation, Environmental; Caulobacteraceae; Creosote; Environmental Monitoring; Industry; Poland; Polycyclic Aromatic Hydrocarbons; Pseudomonas mendocina; Soil; Soil Microbiology; Soil Pollutants
PubMed: 31678701
DOI: 10.1016/j.ecoenv.2019.109843 -
Environmental Microbiology Dec 2008Enrichment and elective culture for methylotrophs from sediment of the River Thames in central London yielded a diversity of pure cultures representing several genera of...
Enrichment and elective culture for methylotrophs from sediment of the River Thames in central London yielded a diversity of pure cultures representing several genera of Gram-negative and Gram-positive bacteria, which were mainly of organisms not generally regarded as typically methylotrophic. Substrates leading to successful isolations included methanol, monomethylamine, dimethylamine, trimethylamine, methanesulfonate and dimethylsulfone. Several isolates were studied in detail and shown by their biochemical and morphological properties and 16S rRNA gene sequencing to be Sphingomonas melonis strain ET35, Mycobacterium fluoranthenivorans strain DSQ3, Rhodococcus erythropolis strain DSQ4, Brevibacterium casei strain MSQ5, Klebsiella oxytoca strains MMA/F and MMA/1, Pseudomonas mendocina strain TSQ4, and Flavobacterium sp. strains MSA/1 and MMA/2. The results show that facultative methylotrophy is present across a wide range of Bacteria, suggesting that turnover of diverse C(1)-compounds is of much greater microbiological and environmental significance than is generally thought. The origins of the genes encoding the enzymes of methylotrophy in diverse heterotrophs need further study, and could further our understanding of the phylogeny and antiquity of methylotrophic systems.
Topics: Bacteria; Biodiversity; DNA, Bacterial; DNA, Ribosomal; Dimethylamines; Genes, rRNA; Geologic Sediments; London; Mesylates; Methane; Methanol; Methyl Methanesulfonate; Methylamines; Molecular Sequence Data; Phylogeny; RNA, Bacterial; RNA, Ribosomal, 16S; Rivers; Sequence Analysis, DNA; Sequence Homology, Nucleic Acid
PubMed: 18681896
DOI: 10.1111/j.1462-2920.2008.01711.x -
Emerging Infectious Diseases Feb 2017We isolated IMP-19-producing Pseudomonas aeruginosa from 7 patients with nosocomial infections linked to contaminated sinks in France. We showed that bla was located on...
We isolated IMP-19-producing Pseudomonas aeruginosa from 7 patients with nosocomial infections linked to contaminated sinks in France. We showed that bla was located on various class 1 integrons among 8 species of gram-negative bacilli detected in sinks: P. aeruginosa, Achromobacter xylosoxidans, A. aegrifaciens, P. putida, Stenotrophomonas maltophilia, P. mendocina, Comamonas testosteroni, and Sphingomonas sp.
Topics: Cross Infection; Drug Resistance, Bacterial; France; Humans; Microbial Sensitivity Tests; Pseudomonas Infections; Pseudomonas aeruginosa; Water Microbiology; beta-Lactamase Inhibitors; beta-Lactamases
PubMed: 28098548
DOI: 10.3201/eid2302.160649 -
Protein Science : a Publication of the... Aug 2006In this work we compare the dynamics and conformational stability of Pseudomonas mendocina lipase enzyme and its F180P/S205G mutant that shows higher activity and... (Comparative Study)
Comparative Study
In this work we compare the dynamics and conformational stability of Pseudomonas mendocina lipase enzyme and its F180P/S205G mutant that shows higher activity and stability for use in washing powders. Our NMR analyses indicate virtually identical structures but reveal remarkable differences in local dynamics, with striking correspondence between experimental data (i.e., (15)N relaxation and H/D exchange rates) and data from Molecular Dynamics simulations. While overall the cores of both proteins are very rigid on the pico- to nanosecond timescale and are largely protected from H/D exchange, the two point mutations stabilize helices alpha1, alpha4, and alpha5 and locally destabilize the H-bond network of the beta-sheet (beta7-beta9). In particular, it emerges that helix alpha5, undergoing some fast destabilizing motions (on the pico- to nanosecond timescale) in wild-type lipase, is substantially rigidified by the mutation of Phe180 for a proline at its N terminus. This observation could be explained by the release of some penalizing strain, as proline does not require any "N-capping" hydrogen bond acceptor in the i+3 position. The combined experimental and simulated data thus indicate that reduced molecular flexibility of the F180P/S205G mutant lipase underlies its increased stability, and thus reveals a correlation between microscopic dynamics and macroscopic thermodynamic properties. This could contribute to the observed altered enzyme activity, as may be inferred from recent studies linking enzyme kinetics to their local molecular dynamics.
Topics: Amino Acid Sequence; Deuterium Exchange Measurement; Enzyme Stability; Hot Temperature; Hydrogen Bonding; Lipase; Nuclear Magnetic Resonance, Biomolecular; Point Mutation; Protein Conformation; Protein Denaturation; Protein Structure, Secondary; Pseudomonas mendocina; Urea
PubMed: 16823035
DOI: 10.1110/ps.062213706 -
Journal of Bacteriology Jan 1983Cells of Pseudomonas stutzeri are naturally transformed by homologous chromosomal DNA; they do not require chemical treatment to become competent. This capacity to...
Cells of Pseudomonas stutzeri are naturally transformed by homologous chromosomal DNA; they do not require chemical treatment to become competent. This capacity to undergo natural transformation was found to be shared by the closely related species P. mendocina, P. alcaligenes, and P. pseudoalcaligenes, but was not detectable in strains of P. aeruginosa, P. perfectomarinus, P. putida, P. fluorescens, or P. syringae. P. stutzeri could be transformed either on plates or in liquid medium. Only double-stranded chromosomal DNA was effective; single-stranded DNA and plasmid DNA were not. DNA fragments larger than 10 kilobase pairs were more effective than smaller fragments. The transformation frequency was proportional to DNA concentration from 1 ng/ml to 1 microgram/ml; higher concentrations were saturating. The maximum frequency, about 10(-4) transformants per recipient cell, was obtained with cells from a culture in the early stationary growth phase. A variety of chromosomal mutations have been transformed, including mutations to auxotrophy and to antibiotic resistance. Other systems for genetic exchange in P. stutzeri have not yet been found; transformation offers a means for the genetic analysis of this metabolically versatile organism.
Topics: Chromosomes, Bacterial; DNA, Bacterial; DNA, Single-Stranded; Genetic Markers; Plasmids; Pseudomonas; Species Specificity; Transformation, Bacterial
PubMed: 6571730
DOI: 10.1128/jb.153.1.93-99.1983 -
Cloning and characterization of the ferulic acid catabolic genes of Sphingomonas paucimobilis SYK-6.Applied and Environmental Microbiology Sep 2002Sphingomonas paucimobilis SYK-6 degrades ferulic acid to vanillin, and it is further metabolized through the protocatechuate 4,5-cleavage pathway. We obtained a Tn5...
Sphingomonas paucimobilis SYK-6 degrades ferulic acid to vanillin, and it is further metabolized through the protocatechuate 4,5-cleavage pathway. We obtained a Tn5 mutant of SYK-6, FA2, which was able to grow on vanillic acid but not on ferulic acid. A cosmid which complemented the growth deficiency of FA2 on ferulic acid was isolated. The 5.2-kb BamHI-EcoRI fragment in this cosmid conferred the transformation activity of ferulic acid to vanillin on Escherichia coli host cells. A sequencing analysis revealed the genes ferB and ferA in this fragment; these genes consist of 852- and 2,127-bp open reading frames, respectively. The deduced amino acid sequence of ferB showed 40 to 48% identity with that of the feruloyl-coenzyme A (CoA) hydratase/lyase genes of Pseudomonas and Amycolatopsis ferulic acid degraders. On the other hand, the deduced amino acid sequence of ferA showed no significant similarity to the feruloyl-CoA synthetase genes of other ferulic acid degraders. However, the deduced amino acid sequence of ferA did show 31% identity with pimeloyl-CoA synthetase of Pseudomonas mendocina 35, which has been classified as a new superfamily of acyl-CoA synthetase (ADP forming) with succinyl-CoA synthetase (L. B. Sánchez, M. Y. Galperin, and M. Müller, J. Biol. Chem. 275:5794-5803, 2000). On the basis of the enzyme activity of E. coli carrying each of these genes, ferA and ferB were shown to encode a feruloyl-CoA synthetase and feruloyl-CoA hydratase/lyase, respectively. p-coumaric acid, caffeic acid, and sinapinic acid were converted to their corresponding benzaldehyde derivatives by the cell extract containing FerA and FerB, thereby indicating their broad substrate specificities. We found a ferB homolog, ferB2, upstream of a 5-carboxyvanillic acid decarboxylase gene (ligW) involved in the degradation of 5,5'-dehydrodivanillic acid. The deduced amino acid sequence of ferB2 showed 49% identity with ferB, and its gene product showed feruloyl-CoA hydratase/lyase activity with a substrate specificity similar to that of FerB. Insertional inactivation of each fer gene in S. paucimobilis SYK-6 suggested that the ferA gene is essential and that ferB and ferB2 genes are involved in ferulic acid degradation.
Topics: Amino Acid Sequence; Cloning, Molecular; Coenzyme A Ligases; Coumaric Acids; DNA, Bacterial; Escherichia coli; Gene Expression; Genes, Bacterial; Molecular Sequence Data; Mutagenesis, Insertional; Phylogeny; Recombinant Proteins; Sequence Homology, Amino Acid; Sphingomonas; Substrate Specificity
PubMed: 12200295
DOI: 10.1128/AEM.68.9.4416-4424.2002 -
Applied and Environmental Microbiology Oct 2006N-Nitrosodimethylamine (NDMA) is a potent carcinogen and an emerging contaminant in groundwater and drinking water. The metabolism of NDMA in mammalian cells has been...
N-Nitrosodimethylamine (NDMA) is a potent carcinogen and an emerging contaminant in groundwater and drinking water. The metabolism of NDMA in mammalian cells has been widely studied, but little information is available concerning the microbial transformation of this compound. The objective of this study was to elucidate the pathway(s) of NDMA biotransformation by Pseudomonas mendocina KR1, a strain that possesses toluene-4-monooxygenase (T4MO). P. mendocina KR1 was observed to initially oxidize NDMA to N-nitrodimethylamine (NTDMA), a novel metabolite. The use of 18O2 and H(2)18O revealed that the oxygen added to NDMA to produce NTDMA was derived from atmospheric O2. Experiments performed with a pseudomonad expressing cloned T4MO confirmed that T4MO catalyzes this initial reaction. The NTDMA produced by P. mendocina KR1 did not accumulate, but rather it was metabolized further to produce N-nitromethylamine (88 to 94% recovery) and a trace amount of formaldehyde (HCHO). Small quantities of methanol (CH3OH) were also detected when the strain was incubated with NDMA but not during incubation with either NTDMA or HCHO. The formation of methanol is hypothesized to occur via a second, minor pathway mediated by an initial alpha-hydroxylation of the nitrosamine. Strain KR1 did not grow on NDMA or mineralize significant quantities of the compound to carbon dioxide, suggesting that the degradation process is cometabolic.
Topics: Biotransformation; Dimethylnitrosamine; Nitroso Compounds; Pseudomonas mendocina; Water Pollutants, Chemical
PubMed: 16950909
DOI: 10.1128/AEM.01535-06 -
Applied and Environmental Microbiology Oct 2001Although iron (Fe) is an essential element for almost all living organisms, little is known regarding its acquisition from the insoluble Fe(III) (hydr)oxides in aerobic...
Although iron (Fe) is an essential element for almost all living organisms, little is known regarding its acquisition from the insoluble Fe(III) (hydr)oxides in aerobic environments. In this study a strict aerobe, Pseudomonas mendocina, was grown in batch culture with hematite, goethite, or ferrihydrite as a source of Fe. P. mendocina obtained Fe from these minerals in the following order: goethite > hematite > ferrihydrite. Furthermore, Fe release from each of the minerals appears to have occurred in excess, as evidenced by the growth of P. mendocina in the medium above that of the insoluble Fe(III) (hydr)oxide aggregates, and this release was independent of the mineral's surface area. These results demonstrate that an aerobic microorganism was able to obtain Fe for growth from several insoluble Fe minerals and did so with various growth rates.
Topics: Aerobiosis; Culture Media; Ferric Compounds; Pseudomonas
PubMed: 11571141
DOI: 10.1128/AEM.67.10.4448-4453.2001 -
Microorganisms Nov 2023Siderophores are low-molecular-weight and high-affinity molecules produced by bacteria under iron-limited conditions. Due to the low iron (III) (Fe) levels in surface...
Siderophores are low-molecular-weight and high-affinity molecules produced by bacteria under iron-limited conditions. Due to the low iron (III) (Fe) levels in surface waters in the marine environment, microbes produce a variety of siderophores. In the current study, halophilic bacteria SMI_1, sp., AABM_9, and AMPPS_5 were isolated from marine surface water of Kalinga beach, Bay of Bengal (Visakhapatnam, Andhra Pradesh, India) and were investigated for siderophore production using the Chrome Azurol S (CAS) assay. The effect of various production parameters was also studied. The optimum production of siderophores for SMI_1 was 93.57% siderophore units (SU) (after 48 h of incubation at 30 °C, pH 8, sucrose as carbon source, sodium nitrate as nitrogen source, 0.4% succinic acid), and for AABM_9, it was 87.18 %SU (after 36 h of incubation period at 30 °C, pH 8, in the presence of sucrose, ammonium sulfate, 0.4% succinic acid). The maximum production of siderophores for AMPPS_5 was 91.17 %SU (after 36 h of incubation at 35 °C, pH 8.5, glucose, ammonium sulfate, 0.4% citric acid). The bacterial isolates SMI_1, AABM_9, and AMPPS_5 showed siderophore production at low Fe concentrations of 0.10 µM, 0.01 µM, and 0.01 µM, respectively. The SMI_1 (73.09 %SU) and AMPPS_5 (68.26 %SU) isolates showed siderophore production in the presence of Zn (10 µM), whereas AABM_9 (50.4 %SU) exhibited siderophore production in the presence of Cu (10 µM). Additionally, these bacterial isolates showed better heavy-metal chelation ability and rapid development in seed germination experiments. Based on these results, the isolates of marine-derived bacteria effectively produced the maximum amount of siderophores, which could be employed in a variety of industrial and environmental applications.
PubMed: 38138017
DOI: 10.3390/microorganisms11122873 -
The Kaohsiung Journal of Medical... Jan 2018Adult bacterial meningitis (ABM) caused by non-Pseudomonas (Ps.) aeruginosa Pseudomonas (NPAP) species infection has rarely been reported. The clinical characteristics... (Comparative Study)
Comparative Study
The clinical characteristics of adult bacterial meningitis caused by non-Pseudomonas (Ps.) aeruginosa Pseudomonas species: A clinical comparison with Ps. aeruginosa meningitis.
Adult bacterial meningitis (ABM) caused by non-Pseudomonas (Ps.) aeruginosa Pseudomonas (NPAP) species infection has rarely been reported. The clinical characteristics of 52 cases of Pseudomonas ABM (11 NPAP- and 41 Ps. aeruginosa-related meningitis) collected during a 30-year study period (1986-2015) were included. Eleven cases of NPAP ABM were identified in the literature, and their clinical data were also collected. Therefore, a total of 22 NPAP ABM cases were enrolled. The clinical characteristics of the NPAP ABM and Ps. aeruginosa ABM groups were compared. Of the implicated NPAP strains, Ps. putida and Ps. stutzeri were the most common (7 cases each), followed by Ps. mendocina in 4, Ps. fluorescens in 1, Ps. fulva in 1, Ps. alcaligenes in 1, and Ps. mosselii in 1. Of the 22 cases, 50% (11/22) had an underlying postneurosurgical state. Fever (77.3%, 17/22) and altered consciousness (45.5%, 10/22) were the most common clinical presentations. Antibiotic non-susceptibility was found in 3 strains of Ps. putida and 1 Ps. mosselii strain. Compared to the patients with Ps. aeruginosa ABM, those with NPAP ABM had a higher incidence of spontaneous infections and a better survival rate. In conclusion, although Ps. putida, Ps. stutzeri and Ps. mendocina were the major implicated strains of NPAP ABM, the clinical characteristics of this specific group of ABM demonstrated marked heterogeneity. Even though the cases with NPAP ABM had better therapeutic results than those with Ps. aeruginosa ABM, further large-scale studies are needed to better delineate this specific group of ABM.
Topics: Adolescent; Adult; Aged; Anti-Bacterial Agents; Confusion; Female; Fever; Humans; Male; Meningitis, Bacterial; Middle Aged; Pseudomonas; Pseudomonas Infections; Pseudomonas aeruginosa; Retrospective Studies; Survival Analysis; Treatment Outcome
PubMed: 29310816
DOI: 10.1016/j.kjms.2017.08.007