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The Plant Cell Jul 1996
Review
Topics: Genetic Predisposition to Disease; Gram-Negative Bacteria; Plant Diseases; Plants; Pseudomonas; Virulence
PubMed: 8785503
DOI: 10.1105/tpc.8.7.1091 -
Metabolic Engineering Jan 2023In recent years branched short-chain dicarboxylates (BSCD) such as itaconic acid gained increasing interest in both medicine and biotechnology. Their use as building...
In recent years branched short-chain dicarboxylates (BSCD) such as itaconic acid gained increasing interest in both medicine and biotechnology. Their use as building blocks for plastics urges for developing microbial upcycling strategies to provide sustainable end-of-life solutions. Furthermore, many BSCD exhibit anti-bacterial properties or exert immunomodulatory effects in macrophages, indicating a medical relevance for this group of molecules. For both of these applications, a detailed understanding of the microbial metabolism of these compounds is essential. In this study, the metabolic pathway of BSCD degradation from Pseudomonas aeruginosa PAO1 was studied in detail by heterologously transferring it to Pseudomonas putida. Heterologous expression of the PA0878-0886 itaconate metabolism gene cluster enabled P. putida KT2440 to metabolize itaconate, (S)- and (R)-methylsuccinate, (S)-citramalate, and mesaconate. The functions of the so far uncharacterized genes PA0879 and PA0881 were revealed and proven to extend the substrate range of the core degradation pathway. Furthermore, the uncharacterized gene PA0880 was discovered to encode a 2-hydroxyparaconate (2-HP) lactonase that catalyzes the cleavage of the itaconate derivative 2-HP to itatartarate. Interestingly, 2-HP was found to inhibit growth of the engineered P. putida on itaconate. All in all, this study extends the substrate range of P. putida to include BSCD for bio-upcycling of high-performance polymers, and also identifies 2-HP as promising candidate for anti-microbial applications.
Topics: Metabolic Networks and Pathways; Pseudomonas; Pseudomonas aeruginosa; Pseudomonas putida; Carboxylic Acids
PubMed: 36581064
DOI: 10.1016/j.ymben.2022.12.008 -
Applied and Environmental Microbiology Sep 2018The olive knot disease ( L.) is caused by the bacterium pv. savastanoi. pv. savastanoi in the olive knot undergoes interspecies interactions with the harmless...
The olive knot disease ( L.) is caused by the bacterium pv. savastanoi. pv. savastanoi in the olive knot undergoes interspecies interactions with the harmless endophyte ; pv. savastanoi and colocalize and form a stable community, resulting in a more aggressive disease. pv. savastanoi and produce the same type of the -acylhomoserine lactone (AHL) quorum sensing (QS) signal, and they share AHLs In this work, we have further studied the AHL QS systems of pv. savastanoi and in order to determine possible molecular mechanism(s) involved in this bacterial interspecies interaction/cooperation. The AHL QS regulons of pv. savastanoi and were determined, allowing the identification of several QS-regulated genes. Surprisingly, the pv. savastanoi QS regulon consisted of only a few loci whereas in many putative metabolic genes were regulated by QS, among which are several involved in carbohydrate metabolism. One of these loci was the aldolase-encoding gene , which was found to be essential for both colocalization of pv. savastanoi and cells inside olive knots as well as knot development. This study further highlighted that pathogens can cooperate with commensal members of the plant microbiome. This is a report on studies of the quorum sensing (QS) systems of the olive knot pathogen pv. savastanoi and olive knot cooperator These two bacterial species form a stable community in the olive knot, share QS signals, and cooperate, resulting in a more aggressive disease. In this work we further studied the QS systems by determining their regulons as well as by studying QS-regulated genes which might play a role in this cooperation. This represents a unique interspecies bacterial virulence model and highlights the importance of bacterial interspecies interaction in disease.
Topics: Bacterial Proteins; Endophytes; Erwinia; Olea; Plant Diseases; Pseudomonas; Quorum Sensing; Virulence
PubMed: 30006401
DOI: 10.1128/AEM.00950-18 -
Journal of Applied Microbiology Oct 2007To screen for novel antagonistic Pseudomonas strains producing both phenazines and biosurfactants that are as effective as Pseudomonas aeruginosa PNA1 in the biocontrol...
AIM
To screen for novel antagonistic Pseudomonas strains producing both phenazines and biosurfactants that are as effective as Pseudomonas aeruginosa PNA1 in the biocontrol of cocoyam root rot caused by Pythium myriotylum.
MATERIAL AND RESULTS
Forty pseudomonads were isolated from the rhizosphere of healthy white and red cocoyam plants appearing in natural, heavily infested fields in Cameroon. In vitro tests demonstrated that Py. myriotylum antagonists could be retrieved from the red cocoyam rhizosphere. Except for one isolate, all antagonistic isolates produced phenazines. Results from whole-cell protein profiling showed that the antagonistic isolates are different from other isolated pseudomonads, while BOX-PCR revealed high genomic similarity among them. 16S rDNA sequencing of two representative strains within this group of antagonists confirmed their relatively low similarity with validly described Pseudomonas species. These antagonists are thus provisionally labelled as unidentified Pseudomonas strains. Among the antagonists, Pseudomonas CMR5c and CMR12a were selected because of their combined production of phenazines and biosurfactants. For strain CMR5c also, production of pyrrolnitrin and pyoluteorin was demonstrated. Both CMR5c and CMR12a showed excellent in vivo biocontrol activity against Py. myriotylum to a similar level as Ps. aeruginosa PNA1.
CONCLUSION
Pseudomonas CMR5c and CMR12a were identified as novel and promising biocontrol agents of Py. myriotylum on cocoyam, producing an arsenal of antagonistic metabolites.
SIGNIFICANCE AND IMPACT OF THE STUDY
Present study reports the identification of two newly isolated fluorescent Pseudomonas strains that can replace the opportunistic human pathogen Ps. aeruginosa PNA1 in the biocontrol of cocoyam root rot and could be taken into account for the suppression of many plant pathogens.
Topics: Crops, Agricultural; Culture Media; Electrophoresis, Polyacrylamide Gel; Genes, Bacterial; Pest Control, Biological; Phenazines; Plant Diseases; Plant Roots; Polymerase Chain Reaction; Pseudomonas; Pythium; Xanthosoma
PubMed: 17897205
DOI: 10.1111/j.1365-2672.2007.03345.x -
Food Chemistry Aug 2024Numerous Pseudomonas species can infect aquatic animals, such as farmed rainbow trout, sea trout, sea bass, and sea bream, by causing disease or stress reactions. In...
Numerous Pseudomonas species can infect aquatic animals, such as farmed rainbow trout, sea trout, sea bass, and sea bream, by causing disease or stress reactions. In aquaculture facilities, a number of Pseudomonas species have been isolated and identified as the main pathogens. The present study describes the characterization of 18 Pseudomonas strains, isolated from fish products using shotgun proteomics. The bacterial proteomes obtained were further analyzed to identify the main functional pathway proteins involved. In addition, this study revealed the presence of 1015 non-redundant peptides related to virulence factors. An additional 25 species-specific peptides were identified as putative Pseudomonas spp. biomarkers. The results constitute the largest dataset, described thus far for the rapid identification and characterization of Pseudomonas species present in edible fish; furthermore, these data can provide the basis for further research into the development of new therapies against these harmful pathogens.
Topics: Animals; Pseudomonas; Proteomics; Fish Products; Bacterial Proteins; Fish Diseases; Proteome; Virulence Factors; Fishes
PubMed: 38631198
DOI: 10.1016/j.foodchem.2024.139342 -
Journal of Applied Microbiology Feb 2012Isolation and characterization of nicotine-degrading bacteria with advantages suitable for the treatment of nicotine-contaminated water and soil and detection of their...
AIMS
Isolation and characterization of nicotine-degrading bacteria with advantages suitable for the treatment of nicotine-contaminated water and soil and detection of their metabolites.
METHODS AND RESULTS
A novel nicotine-degrading bacterial strain was isolated from tobacco field soil. Based on morphological and physiochemical properties and sequence of 16S rDNA, the isolate was identified as Pseudomonas sp., designated as CS3. The optimal culture conditions of strain CS3 for nicotine degradation were 30°C and pH 7·0. However, the strain showed broad pH adaptability with high nicotine-degrading activity between pH 6·0 and 10·0. Strain CS3 could decompose nicotine nearly completely within 24 h in liquid culture (1000 mg L(-1) nicotine) or within 72 h in soil (1000-2500 mg kg(-1) nicotine) and could endure up to 4000 mg L(-1) nicotine in liquid media and 5000 mg kg(-1) nicotine in soil. Degradation tests in flask revealed that the strain had excellent stability and high degradation activity during the repetitive degradation processes. Additionally, three intermediates, 3-(3,4-dihydro-2H-pyrrol-5-yl) pyridine, 1-methyl-5-(3-pyridyl) pyrrolidine-2-ol and cotinine, were identified by GC/MS and NMR analyses.
CONCLUSIONS
The isolate CS3 showed outstanding nicotine-degrading characteristics such as high degradation efficiency, strong substrate endurance, broad pH adaptability, and stability and persistence in repetitive degradation processes and may serve as an excellent candidate for applications in the bioaugmentation process to treat nicotine-contaminated water and soil. Also, detection of nicotine metabolites suggests that strain CS3 might decompose nicotine via a unique nicotine-degradation pathway.
SIGNIFICANCE AND IMPACT OF THE STUDY
The advantage of applying the isolated strain lies in broad pH adaptability and stability and persistence in repetitive use, the properties previously less focused in other nicotine-degrading micro-organisms. The strain might decompose nicotine via a nicotine-degradation pathway different from those of other nicotine-utilizing Pseudomonas bacteria reported earlier, another highlight in this study.
Topics: Biodegradation, Environmental; Hydrogen-Ion Concentration; Nicotine; Phylogeny; Pseudomonas; RNA, Ribosomal, 16S; Soil Microbiology; Soil Pollutants; Temperature; Water Pollutants, Chemical
PubMed: 22129149
DOI: 10.1111/j.1365-2672.2011.05208.x -
The Yale Journal of Biology and Medicine Dec 1971
Topics: Adult; Aged; Body Temperature; Child; Female; Humans; Male; Microbial Sensitivity Tests; Middle Aged; Pseudomonas; Pseudomonas Infections; Pseudomonas fluorescens; Urine
PubMed: 5002396
DOI: No ID Found -
Journal of Bacteriology Nov 2000Pseudomonas sp. strain B13 and Pseudomonas putida OUS82 were genetically tagged with the green fluorescent protein and the Discosoma sp. red fluorescent protein, and the... (Comparative Study)
Comparative Study
Pseudomonas sp. strain B13 and Pseudomonas putida OUS82 were genetically tagged with the green fluorescent protein and the Discosoma sp. red fluorescent protein, and the development and dynamics occurring in flow chamber-grown two-colored monospecies or mixed-species biofilms were investigated by the use of confocal scanning laser microscopy. Separate red or green fluorescent microcolonies were formed initially, suggesting that the initial small microcolonies were formed simply by growth of substratum attached cells and not by cell aggregation. Red fluorescent microcolonies containing a few green fluorescent cells and green fluorescent microcolonies containing a few red fluorescent cells were frequently observed in both monospecies and two-species biofilms, suggesting that the bacteria moved between the microcolonies. Rapid movement of P. putida OUS82 bacteria inside microcolonies was observed before a transition from compact microcolonies to loose irregularly shaped protruding structures occurred. Experiments involving a nonflagellated P. putida OUS82 mutant suggested that the movements between and inside microcolonies were flagellum driven. The results are discussed in relation to the prevailing hypothesis that biofilm bacteria are in a physiological state different from planktonic bacteria.
Topics: Biofilms; DNA Transposable Elements; Green Fluorescent Proteins; Luminescent Proteins; Microscopy, Confocal; Molecular Sequence Data; Pseudomonas; Pseudomonas putida; Red Fluorescent Protein
PubMed: 11053394
DOI: 10.1128/JB.182.22.6482-6489.2000 -
Proceedings of the National Academy of... Nov 1999One mechanism of silver resistance in microorganisms is accumulation of the metal ions in the cell. Here, we report on the phenomenon of biosynthesis of silver-based...
One mechanism of silver resistance in microorganisms is accumulation of the metal ions in the cell. Here, we report on the phenomenon of biosynthesis of silver-based single crystals with well-defined compositions and shapes, such as equilateral triangles and hexagons, in Pseudomonas stutzeri AG259. The crystals were up to 200 nm in size and were often located at the cell poles. Transmission electron microscopy, quantitative energy-dispersive x-ray analysis, and electron diffraction established that the crystals comprise at least three different types, found both in whole cells and thin sections. These Ag-containing crystals are embedded in the organic matrix of the bacteria. Their possible potential as organic-metal composites in thin film and surface coating technology is discussed.
Topics: Crystallization; Culture Media; Pseudomonas; Silver; Silver Compounds; Silver Nitrate
PubMed: 10570120
DOI: 10.1073/pnas.96.24.13611 -
BMC Genomics Apr 2013Some Pseudomonas strains function as predominant plant growth-promoting rhizobacteria (PGPR). Within this group, Pseudomonas chlororaphis and Pseudomonas fluorescens are...
BACKGROUND
Some Pseudomonas strains function as predominant plant growth-promoting rhizobacteria (PGPR). Within this group, Pseudomonas chlororaphis and Pseudomonas fluorescens are non-pathogenic biocontrol agents, and some Pseudomonas aeruginosa and Pseudomonas stutzeri strains are PGPR. P. chlororaphis GP72 is a plant growth-promoting rhizobacterium with a fully sequenced genome. We conducted a genomic analysis comparing GP72 with three other pseudomonad PGPR: P. fluorescens Pf-5, P. aeruginosa M18, and the nitrogen-fixing strain P. stutzeri A1501. Our aim was to identify the similarities and differences among these strains using a comparative genomic approach to clarify the mechanisms of plant growth-promoting activity.
RESULTS
The genome sizes of GP72, Pf-5, M18, and A1501 ranged from 4.6 to 7.1 M, and the number of protein-coding genes varied among the four species. Clusters of Orthologous Groups (COGs) analysis assigned functions to predicted proteins. The COGs distributions were similar among the four species. However, the percentage of genes encoding transposases and their inactivated derivatives (COG L) was 1.33% of the total genes with COGs classifications in A1501, 0.21% in GP72, 0.02% in Pf-5, and 0.11% in M18. A phylogenetic analysis indicated that GP72 and Pf-5 were the most closely related strains, consistent with the genome alignment results. Comparisons of predicted coding sequences (CDSs) between GP72 and Pf-5 revealed 3544 conserved genes. There were fewer conserved genes when GP72 CDSs were compared with those of A1501 and M18. Comparisons among the four Pseudomonas species revealed 603 conserved genes in GP72, illustrating common plant growth-promoting traits shared among these PGPR. Conserved genes were related to catabolism, transport of plant-derived compounds, stress resistance, and rhizosphere colonization. Some strain-specific CDSs were related to different kinds of biocontrol activities or plant growth promotion. The GP72 genome contained the cus operon (related to heavy metal resistance) and a gene cluster involved in type IV pilus biosynthesis, which confers adhesion ability.
CONCLUSIONS
Comparative genomic analysis of four representative PGPR revealed some conserved regions, indicating common characteristics (metabolism of plant-derived compounds, heavy metal resistance, and rhizosphere colonization) among these pseudomonad PGPR. Genomic regions specific to each strain provide clues to its lifestyle, ecological adaptation, and physiological role in the rhizosphere.
Topics: Comparative Genomic Hybridization; Genome, Bacterial; Phylogeny; Plant Development; Plant Diseases; Pseudomonas; Rhizosphere
PubMed: 23607266
DOI: 10.1186/1471-2164-14-271