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FEMS Microbiology Ecology Dec 2009A long-term field experiment was carried out to estimate the efficiency of bioaugmentation in combination with phytoremediation for oil shale chemical industry solid...
A long-term field experiment was carried out to estimate the efficiency of bioaugmentation in combination with phytoremediation for oil shale chemical industry solid waste dump area remediation. Soil samples for microbiological and chemical analysis were collected during 3 years after bacterial biomass application. Microbial communities in soil samples were analysed using both culture-based and molecular methods. The survival of the introduced bacterial strains was confirmed by cultivation-based Box-PCR genomic fingerprints and denaturing gradient gel electrophoresis fingerprinting of the 16S rRNA and lmPH genes. The introduced bacterial strains as well as corresponding catabolic genes were recovered several years after biomass application, predominantly from the rhizosphere of birches. Soil samples from bioaugmented plots showed an elevated potential for degradation of phenolic compounds even 40 months after treatment. Based on our results we can conclude that the introduced Pseudomonas strains both survived, and their metabolic traits have persisted at the contaminated site over a long period of time.
Topics: Biodegradation, Environmental; DNA Fingerprinting; DNA, Bacterial; Industrial Waste; Pseudomonas; RNA, Ribosomal, 16S; Refuse Disposal; Soil; Soil Microbiology
PubMed: 19732146
DOI: 10.1111/j.1574-6941.2009.00754.x -
Journal of Dairy Science Oct 2017Pseudomonas species are well recognized as dairy product spoilage organisms, particularly due to their ability to grow at refrigeration temperatures. Although...
Pseudomonas species are well recognized as dairy product spoilage organisms, particularly due to their ability to grow at refrigeration temperatures. Although Pseudomonas-related spoilage usually manifests itself in flavor, odor, and texture defects, which are typically due to production of bacterial enzymes, Pseudomonas is also reported to cause color defects. Because of consumer complaints, a commercial dairy company shipped 4 samples of high temperature, short time (HTST)-pasteurized milk with distinctly gray colors to our laboratory. Bacterial isolates from all 4 samples were identified as Pseudomonas azotoformans. All isolates shared the same partial 16S rDNA sequence and showed black pigmentation on Dichloran Rose Bengal Chloramphenicol agar. Inoculation of one pigment-producing P. azotoformans isolate into HTST-pasteurized fluid milk led to development of gray milk after 14 d of storage at 6°C, but only in containers that had half of the total volume filled with milk (∼500 mL of milk in ∼1,000-mL bottles). We conclusively demonstrate that Pseudomonas can cause a color defect in fluid milk that manifests in gray discoloration, adding to the palette of color defects known to be caused by Pseudomonas. This information is of considerable interest to the dairy industry, because dairy processors and others may not typically associate black or gray colors in fluid milk with the presence of microbial contaminants but rather with product tampering (e.g., addition of ink) or other inadvertent chemical contamination.
Topics: Animals; DNA, Ribosomal; Hot Temperature; Milk; Pasteurization; Pigmentation; Pseudomonas; Refrigeration
PubMed: 28755936
DOI: 10.3168/jds.2017-12650 -
Scientific Reports Apr 2019In this paper, we describe the isolation of an unusual type of high molecular weight monorhamnolipid attached to esters of palmitic, stearic, hexa and octadecanoic acids...
In this paper, we describe the isolation of an unusual type of high molecular weight monorhamnolipid attached to esters of palmitic, stearic, hexa and octadecanoic acids as against the routinely reported di-rhamnolipids linked to hydroxydecanoic acids. The bioemulsifier was column-purified and the chemical nature of the compound was elucidated using FT-IR, GC-MS and 1D [H andC] and 2D NMR. This monorhamnolipid is extracted from a bacterium, Pseudomonas guganensis and is not reported to have biological activities, let alone emulsification abilities. The bacterium continually produced rhamnolipids when nourished with n-hexadecane as its lone carbon source. The extracellularly secreted monorhamnolipids are capable of degrading hydrocarbons, with most preference to n-hexadecane [EI of 56 ± 1.42% by 2 mL of the spent medium]. Whilst the crude ethyl acetate partitioned extract had an EI of 65 ± 1.43%; the purified rhamnolipid product showed 78 ± 1.75% both at 12.5 mg/mL concentration. The used-up n-hexadecane is biotransformed to prepare its own rhamnolipids which in return is utilized to degrade n-alkanes thus creating a circular pathway which is proposed herein. This bacterium can be seen as a new source of bioemulsifier to reduce hydrocarbon in polluted waters.
Topics: Emulsions; Glycolipids; India; Pseudomonas
PubMed: 30979908
DOI: 10.1038/s41598-019-42045-9 -
Applied and Environmental Microbiology Nov 2000Pyoverdine isoelectric focusing analysis and pyoverdine-mediated iron uptake were used as siderotyping methods to analyze a collection of 57 northern and central...
Pyoverdine isoelectric focusing analysis and pyoverdine-mediated iron uptake were used as siderotyping methods to analyze a collection of 57 northern and central European isolates of P. tolaasii and "P. reactans." The bacteria, isolated from cultivated Agaricus bisporus or Pleurotus ostreatus mushroom sporophores presenting brown blotch disease symptoms, were identified according to the white line test (W. C. Wong and T. F. Preece, J. Appl. Bacteriol. 47:401-407, 1979) and their pathogenicity towards A. bisporus and were grouped into siderovars according to the type of pyoverdine they produced. Seventeen P. tolaasii isolates were recognized, which divided into two siderovars, with the first one containing reference strains and isolates of various geographical origins while the second one contained Finnish isolates exclusively. The 40 "P. reactans" isolates divided into eight siderovars. Pyoverdine isoelectric focusing profiles and cross-uptake studies demonstrated an identity for some "P. reactans" isolates, with reference strains belonging to the P. fluorescens biovars II, III, or V. Thus, the easy and rapid methods of siderotyping proved to be reliable by supporting and strengthening previous taxonomical data. Moreover, two potentially novel pyoverdines characterizing one P. tolaasii siderovar and one "P. reactans" siderovar were found.
Topics: Agaricus; Bacterial Typing Techniques; Iron; Isoelectric Focusing; Oligopeptides; Pigments, Biological; Pleurotus; Pseudomonas; Siderophores
PubMed: 11055932
DOI: 10.1128/AEM.66.11.4834-4841.2000 -
The ISME Journal Oct 2016Bacteria of the genus Pseudomonas occupy diverse environments. The Pseudomonas fluorescens group is particularly well-known for its plant-beneficial properties including...
Bacteria of the genus Pseudomonas occupy diverse environments. The Pseudomonas fluorescens group is particularly well-known for its plant-beneficial properties including pathogen suppression. Recent observations that some strains of this group also cause lethal infections in insect larvae, however, point to a more versatile ecology of these bacteria. We show that 26 P. fluorescens group strains, isolated from three continents and covering three phylogenetically distinct sub-clades, exhibited different activities toward lepidopteran larvae, ranging from lethal to avirulent. All strains of sub-clade 1, which includes Pseudomonas chlororaphis and Pseudomonas protegens, were highly insecticidal regardless of their origin (animals, plants). Comparative genomics revealed that strains in this sub-clade possess specific traits allowing a switch between plant- and insect-associated lifestyles. We identified 90 genes unique to all highly insecticidal strains (sub-clade 1) and 117 genes common to all strains of sub-clade 1 and present in some moderately insecticidal strains of sub-clade 3. Mutational analysis of selected genes revealed the importance of chitinase C and phospholipase C in insect pathogenicity. The study provides insight into the genetic basis and phylogenetic distribution of traits defining insecticidal activity in plant-beneficial pseudomonads. Strains with potent dual activity against plant pathogens and herbivorous insects have great potential for use in integrated pest management for crops.
Topics: Animals; Genomics; Host Specificity; Larva; Lepidoptera; Phylogeny; Plants; Pseudomonas; Virulence
PubMed: 26894448
DOI: 10.1038/ismej.2016.5 -
Journal of Microbiology and... Nov 2022The need to discover new types of antimicrobial agents has grown since the emergence of antibiotic-resistant pathogens that threaten human health. The world's oceans,...
The need to discover new types of antimicrobial agents has grown since the emergence of antibiotic-resistant pathogens that threaten human health. The world's oceans, comprising complex niches of biodiversity, are a promising environment from which to extract new antibiotics-like compounds. In this study, we newly isolated sp. NIBR-H-19 from the gut of the sea roach and present both phenotypes and genomic information consisting of 6,184,379 bp in a single chromosome possessing a total of 5,644 protein-coding genes. Genomic analysis of the isolated species revealed that numerous genes involved in antimicrobial secondary metabolites are predicted throughout the whole genome. Moreover, our analysis showed that among twenty-five pathogenic bacteria, the growth of three pathogens, including , and , was significantly inhibited by the culture of sp. NIBR-H-19. The characterization of marine microorganisms with biochemical assays and genomics tools will help uncover the biosynthesis and action mechanism of antimicrobial metabolites for development as antagonistic probiotics against fish pathogens in an aquatic culture system.
Topics: Animals; Humans; Pseudomonas; Anti-Bacterial Agents; Staphylococcus aureus; Staphylococcal Infections; Republic of Korea
PubMed: 36310358
DOI: 10.4014/jmb.2208.08043 -
The Journal of General and Applied... Feb 2008A bacterial strain, WL(T), which was isolated from an activated sludge, was able to degrade alkylphenols. 16S rDNA sequence analysis indicated that strain WL(T) belonged...
A bacterial strain, WL(T), which was isolated from an activated sludge, was able to degrade alkylphenols. 16S rDNA sequence analysis indicated that strain WL(T) belonged to the genus Pseudomonas (sensu stricto) and formed a monophyletic clade with the type strain of Pseudomonas graminis and other members in the Pseudomonas putida subcluster with sequence similarity values higher than 97%. Genomic relatedness based on DNA-DNA hybridization of strain WL(T) to these strains is 2-41%. Strain WL(T) contained ubiquinone-9 as the main respiratory quinone, and the G+C content of DNA was 66 mol%. The organism contained hexadecanoic acid (16:0), hexadecenoic acid (16:1) and octadecenoic acid (18:1) as major cellular fatty acids. The hydroxy fatty acids detected were 3-hydroxydecanoic acid (3-OH 10:0), 3-hydroxydodecanoic acid (3-OH 12:0) and 2-hydroxydodecanoic acid (2-OH 12:0). These results, as well as physiological and biochemical characteristics clearly indicate that the strain WL(T) represents a new Pseudomonas species, for which the name Pseudomonas japonica is proposed. The type strain is strain WL(T) (=IAM 15071T=TISTR 1526T).
Topics: Bacterial Typing Techniques; Base Composition; Fatty Acids; Genotype; Molecular Sequence Data; Nucleic Acid Hybridization; Phenols; Phenotype; Phylogeny; Pseudomonas; RNA, Ribosomal, 16S; Sequence Analysis, DNA; Sewage; Species Specificity; Tokyo
PubMed: 18323682
DOI: 10.2323/jgam.54.61 -
Journal of Clinical Microbiology Aug 1980Biochemical characteristics and antibiotic susceptibilities of 12 strains of colistin-resistant pseudomonads isolated from clinical specimens are reported. The isolates...
Biochemical characteristics and antibiotic susceptibilities of 12 strains of colistin-resistant pseudomonads isolated from clinical specimens are reported. The isolates were short, oxidase-positive, nonfluorescing, gram-negative rods that failed to grow on salmonella-shigella or cetrimide agars, to decarboxylate amino acids, and to reduce nitrates. Most strains peptonized litmus milk and grew at 42 degrees C. Glucose, lactose, maltose, xylose, and fructose were slowly oxidized, whereas sucrose was not. Two homogeneous species were found and tentatively listed as Pseudomonas sp. 1 and Pseudomonas sp. 2, and these were differentiated by gelatin and starch hydrolysis, oxidation of mannitol, and alkalinization of allantoin. The two species were shown to differ from the Center for Disease Control Va group biotype CDC Va-1 in both biochemical characteristics and susceptibility to the aminoglycosides.
Topics: Anti-Bacterial Agents; Carbohydrate Metabolism; Colistin; Drug Resistance, Microbial; Humans; Military Medicine; Oxidation-Reduction; Pseudomonas; Pseudomonas Infections
PubMed: 7229004
DOI: 10.1128/jcm.12.2.156-160.1980 -
Applied and Environmental Microbiology Dec 2019Since the discovery of penicillin, microbes have been a source of antibiotics that inhibit the growth of pathogens. However, with the evolution of multidrug-resistant...
Since the discovery of penicillin, microbes have been a source of antibiotics that inhibit the growth of pathogens. However, with the evolution of multidrug-resistant (MDR) strains, it remains unclear if there is an abundant or limited supply of natural products to be discovered that are effective against MDR isolates. To identify strains that are antagonistic to pathogens, we examined a set of 471 globally derived environmental strains (env-Ps) for activity against a panel of 65 pathogens including spp., spp., , and spp. isolated from the lungs of cystic fibrosis (CF) patients. From more than 30,000 competitive interactions, 1,530 individual inhibitory events were observed. While strains from water habitats were not proportionate in antagonistic activity, MDR CF-derived pathogens (CF-Ps) were less susceptible to inhibition by env-Ps, suggesting that fewer natural products are effective against MDR strains. These results advocate for a directed strategy to identify unique drugs. To facilitate discovery of antibiotics against the most resistant pathogens, we developed a workflow in which phylogenetic and antagonistic data were merged to identify strains that inhibit MDR CF-Ps and subjected those env-Ps to transposon mutagenesis. Six different biosynthetic gene clusters (BGCs) were identified from four strains whose products inhibited pathogens including carbapenem-resistant BGCs were rare in databases, suggesting the production of novel antibiotics. This strategy can be utilized to facilitate the discovery of needed antibiotics that are potentially active against the most drug-resistant pathogens. Carbapenem-resistant is difficult to treat and has been deemed by the World Health Organization as a priority one pathogen for which antibiotics are most urgently needed. Although metagenomics and bioinformatic studies suggest that natural bacteria remain a source of novel compounds, the identification of genes and their products specific to activity against MDR pathogens remains problematic. Here, we examine water-derived pseudomonads and identify gene clusters whose compounds inhibit CF-derived MDR pathogens, including carbapenem-resistant .
Topics: Anti-Bacterial Agents; Antibiosis; Bacteria; Drug Resistance, Multiple, Bacterial; Microbial Sensitivity Tests; Pseudomonas
PubMed: 31540982
DOI: 10.1128/AEM.01438-19 -
The Plant Cell Jan 1991To develop a model system for molecular genetic analysis of plant-pathogen interactions, we studied the interaction between Arabidopsis thaliana and the bacterial...
To develop a model system for molecular genetic analysis of plant-pathogen interactions, we studied the interaction between Arabidopsis thaliana and the bacterial pathogen Pseudomonas syringae pv tomato (Pst). Pst strains were found to be virulent or avirulent on specific Arabidopsis ecotypes, and single ecotypes were resistant to some Pst strains and susceptible to others. In many plant-pathogen interactions, disease resistance is controlled by the simultaneous presence of single plant resistance genes and single pathogen avirulence genes. Therefore, we tested whether avirulence genes in Pst controlled induction of resistance in Arabidopsis. Cosmids that determine avirulence were isolated from Pst genomic libraries, and the Pst avirulence locus avrRpt2 was defined. This allowed us to construct pathogens that differed only by the presence or absence of a single putative avirulence gene. We found that Arabidopsis ecotype Col-0 was susceptible to Pst strain DC3000 but resistant to the same strain carrying avrRpt2, suggesting that a single locus in Col-0 determines resistance. As a first step toward genetically mapping the postulated resistance locus, an ecotype susceptible to infection by DC3000 carrying avrRpt2 was identified. The avrRpt2 locus from Pst was also moved into virulent strains of the soybean pathogen P. syringae pv glycinea to test whether this locus could determine avirulence on soybean. The resulting strains induced a resistant response in a cultivar-specific manner, suggesting that similar resistance mechanisms may function in Arabidopsis and soybean.
Topics: Cloning, Molecular; Genes, Bacterial; Plant Diseases; Plants; Pseudomonas; Glycine max; Virulence
PubMed: 1824334
DOI: 10.1105/tpc.3.1.49