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Literatura académica sobre el tema "Pseudomonas fluorescens"

Autor: Grafiati

Publicado: 4 de junio de 2021

Última modificación: 24 de agosto de 2024

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Artículos de revistas sobre el tema "Pseudomonas fluorescens"

1

Gopal, Surendra, Reshma Francis y A. K. Sreelatha. "Impact of soil temperature, pH and carbon dioxide on the population and efficiency of fluorescent pseudomonad in the rhizosphere soil of Pokkali rice". Environment Conservation Journal 24, n.º 1 (8 de enero de 2023): 163–70. http://dx.doi.org/10.36953/ecj.10262239.

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The present study was aimed at the evaluation of soil temperature, pH and carbon dioxide evolution on the number and efficiency of fluorescent pseudomonads around the root system of Pokkali rice at Vytilla in Ernakulam district of Kerala. Two plots (40 m2) comprising control (without application of Pseudomonas fluorescens) and P. fluorescens treated plants were used for the field experiment. The isolates of fluorescent Pseudomonads or Pseudomonas fluorescence were counted and their efficiency was assessed for IAA, ammonia, HCN and siderophore production. Simultaneously, soil temperature, pH, and carbon dioxide evolution were also recorded. A total of 6 fluorescent pseudomonads (VPJU, VPJL, VPAU1, VPAU2, VPAU3 and VPAU4) were found during the crop period. All the isolates produced IAA and ammonia with varying degrees of intensity. Three isolates (VPAU1, VPAU3 and VPAU4) produced HCN, and no microbial isolates produced siderophore. The effect of soil temperature, pH, EC and carbon dioxide evolution was correlated with the number of fluorescent pseudomonads in the soil. The bacteria were significantly afflicted by pH and EC, whereas soil temperature and CO2 evolution did not show any effect on the number of fluorescent pseudomonads. There was no significant influence of soil temperature, pH, EC and carbon dioxide evolution on indole acetic acid production, ammonia, and HCN production. Inoculated Pseudomonas fluorescence did not survive in Pokkali rice fields. However, further studies are needed for at least three seasons in Pokkali soils to confirm the results of the present study.

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2

FARRAG, SEHAM A. y ELMER H. MARTH. "Behavior of Listeria monocytogenes when Incubated Together with Pseudomonas Species in Tryptose Broth at 7 and 13°C". Journal of Food Protection 52, n.º 8 (1 de agosto de 1989): 536–39. http://dx.doi.org/10.4315/0362-028x-52.8.536.

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Tryptose broth (TB) was inoculated with Listeria monocytogenes (strain Scott A or California), Pseudomonas aeruginosa, Pseudomonas flourescens, or a combination of L. monocytogenes plus Pseudomonas species, and incubated at 7 or 13°C for 8 weeks. McBride Listeria Agar was used to determine numbers of L. monocytogenes and Pseudomonas Isolation Agar to enumerate Pseudomonas species at 0, 7, 14, 28, 42, or 56 d. At 13°C, presence of P. fluorescens had a slight negative effect on growth of L. monocytogenes strain Scott A, and was somewhat detrimental to its survival during the extended incubation. Growth of L. monocytogenes strain California was retarded by presence of P. fluorescens although the maximum population achieved by the pathogen was greater in the presence rather than absence of the pseudomonad; the pseudomonad did have a negative effect on survival of the pathogen. At the same temperature, P. aeruginosa had a negative effect on survival of L. monocytogenes strain California, but had essentially no effect on the other strain of the pathogen. Neither strain of L. monocytogenes affected growth of P. fluorescens nor P. aeruginosa. At 13°C the pH of TB generally decreased when L. monocytogenes grew by itself but increased when either pseudomonad grew by itself or together with the pathogen. At 7°C, growth of both pseudomonads was minimal. Presence of non-growing cells of P. fluorescens retarded somewhat growth of both L. monocytogenes strains early during the incubation. P. aeruginosa had no detectable effect on either strain of L. monocytogenes. The pH of TB decreased when L. monocytogenes grew by itself or together with either pseudomonad, and remained unchanged in TB inoculated with either pseudomonad.

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3

Tryfinopoulou, P., E. Tsakalidou y G. J. E. Nychas. "Characterization of Pseudomonas spp. Associated with Spoilage of Gilt-Head Sea Bream Stored under Various Conditions". Applied and Environmental Microbiology 68, n.º 1 (enero de 2002): 65–72. http://dx.doi.org/10.1128/aem.68.1.65-72.2002.

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ABSTRACT The population dynamics of pseudomonads in gilt-head sea bream Mediterranean fish (Sparus aurata) stored under different conditions were studied. Phenotypic analysis and sodium dodecyl sulfate-polyacrylamide gel electrophoresis of whole-cell proteins were performed to identify a total of 106 Pseudomonas strains isolated from S. aurata stored under different temperatures (at 0, 10, and 20°C) and packaging conditions (air and a modified atmosphere of 40% CO2-30% N2-30% O2). Pseudomonas lundensis was the predominant species, followed by Pseudomonas fluorescens, while Pseudomonas fragi and Pseudomonas putida were detected less frequently. Fluorescent Pseudomonas strains dominated under air conditions, while proteolytic and less lipolytic strains dominated under modified-atmosphere packaging. Different storage conditions appear to govern the selection of pseudomonads in gilt-head sea bream fish.

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4

Velusamy, Palaniyandi, J. Ebenezar Immanuel, Samuel S. Gnanamanickam y Linda Thomashow. "Biological control of rice bacterial blight by plant-associated bacteria producing 2,4-diacetylphloroglucinol". Canadian Journal of Microbiology 52, n.º 1 (1 de enero de 2006): 56–65. http://dx.doi.org/10.1139/w05-106.

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Certain plant-associated strains of fluorescent Pseudomonas spp. are known to produce the antimicrobial antibiotic 2,4-diacetylphloroglucinol (DAPG). It has antibacterial, antifungal, antiviral, and antihelminthic properties and has played a significant role in the biological control of tobacco, wheat, and sugar beet diseases. It has never been reported from India and has not been implicated in the biological suppression of a major disease of the rice crop. Here, we report that a subpopulation of 27 strains of plant-associated Pseudomonas fluorescens screened in a batch of 278 strains of fluorescent pseudomonads produced DAPG. The DAPG production was detected by a PCR-based screening method that used primers Phl2a and Phl2b and amplified a 745-bp fragment characteristic of DAPG. HPLC,1H NMR, and IR analyses provided further evidence for its production. We report also that this compound inhibited the growth of the devastating rice bacterial blight pathogen Xanthomonas oryzae pv. oryzae in laboratory assays and suppressed rice bacterial blight up to 59%–64% in net-house and field experiments. Tn5 mutants defective in DAPG production (Phl–) of P. fluorescens PTB 9 were much less effective in their suppression of rice bacterial blight.Key words: biocontrol, 2,4-diacetylphloroglucinol, Pseudomonas fluorescens, rice, Xanthomonas oryzae pv. oryzae.

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5

Aloysius Ng. Lende, Laurensius Lehar y Heny MC Sine. "Application of organic fertilizer and Pseudomonas fluorescens on the growth and yield of shallot cultivar Sabu Raijua (Allium ascalonicum L .) in dry land". GSC Advanced Research and Reviews 5, n.º 2 (30 de noviembre de 2020): 123–30. http://dx.doi.org/10.30574/gscarr.2020.5.2.0105.

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The specific objectives of this study were 1 ) knowing certain types of organic fertilizers on the growth of shallots 2 ) knowing the concentrations of Pseudomonas fluorescenss certain the growth of shallots, 3 ) knowing the types of organic fertilizers and the concentrations Pseudomonas fluorescens specificity increase the optimal yield of shallots. To achieve this goal, this research was conducted using factorial experiments with a split Plot Design with 10 treatments and 3 replications. So that there are 10 treatment combinations of a total number of 30 experimental plots. There were 2 factors that were tried, namely the first factor of Organic Fertilizer as the main plot, namely: cow manure 10 ton ha-1 (K1), chicken manure 10 ton ha-1 (K2). While the second factor as the subplot is the concentration of Pseudomonas fluorescens: Watering with water (as a control) 100 ml (P0), Watering with a concentration of Pseudomonas fluorescens 5 ml + normal water 95 ml (P1), Watering with a concentration of Pseudomonas fluorescens 10 + ordinary water 90 ml (P2), sprinkling with a concentration of Pseudomonas fluorescens 15 ml + 85 ml plain water (P3), Flushing with a concentration of Pseudomonas fluorescens 20 + ordinary water 80 ml (P4). The shallot cultivar of Sabu Raijua which was given organic fertilizer of 10 tonnes of chicken manure. Ha-1 and a concentration of Pseudomonas fluorescens 20 + 80 ml of plain water gave the highest growth component at the age of 10 WAP, namely at the age of 10 WAP, namely plant height (37.667cm). Leaves (34, 800 trees), number of tillers (10, 533 trees). The results of shallot bulbs of Sabu Raijua cultivar from organic fertilizer treatment of 10 ton ha-chicken manure1s with a concentration of Pseudomonas fluorescens 20 ml + 80 ml water resulted in components, namely tuber weight per plot (276.70 g ), number of tubers per plot (291, 70 tubers ).

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6

Armarkar, Sarika A., R. M. Gade y Mina D. Koche. "Growth Promotion Activity And Growth Pattern Of Pseudomonas Fluorescens On Different Solid Media". Journal of Plant Disease Sciences 17, n.º 1 (9 de agosto de 2022): 22–27. http://dx.doi.org/10.48165/jpds.2022.1706.

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Study was conducted in vitro to study the growth promotion activity and growth pattern of Pseudomonas fluorescens on different solid media. Soil samples were collected randomly from rhizosphere of citrus plants for isolation of Pseudomonas. Twenty six isolates was isolated, out of twenty six isolates eight isolates showed abiliity of siderophore production, thirteen isolates showed positiveness for IAA production, nine isolates showed phosphate solubilization and seven isolates were positive for HCN production. For growth pattern study of P. fluorescens three different media i.e. King’s B, Pseudomonas agar and nutrient agar used. All the isolates showed fast growth on King’s B followed by Pseudomonas agar and nutrient agar. Mostly Pseudomonas fluorescens produced greenish yellow coloured colonies on King’s B and Pseudomonas agar and dull yellowish coloured colony and creamy white coloured colony on nutrient agar. Fluorescent pigmentation was observed on King’B and Pseudomonas agar medium.

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7

Gottlieb, Tom, Glenn Funnell y Iain Gosbell. "Pseudomonas fluorescens pseudobacteraemia". Medical Journal of Australia 155, n.º 11-12 (diciembre de 1991): 854–55. http://dx.doi.org/10.5694/j.1326-5377.1991.tb94085.x.

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8

Snopková, Kateřina, Kristýna Dufková y David Šmajs. "Pseudomonas prosekii isolated in Antarctica inhibits plantpathogenic strains of Pseudomonas viridiflava and Pseudomonas fluorescens". Czech Polar Reports 11, n.º 2 (11 de febrero de 2022): 270–78. http://dx.doi.org/10.5817/cpr2021-2-18.

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Pseudomonas-caused plant diseases are present worldwide and affect most of the major lineages of higher plants which, as a consequence, may result in significant economic losses. Despite the use of bacteriocins produced by rhizosphere and soil bacteria has been nowadays considered as novel crop protection approach, antagonistic interactions of cold-adapted isolates toward agriculturally important phytopathogenic bacteria have not been studied yet. In this study, we tested inhibition activity of Antarctic Pseudomonas spp. against phytopathogenic pseudomonads. Four Antarctic stains (P. prosekii CCM 8878, CCM 8879, and CCM 8881 and Pseudomonas sp. CCM 8880) inhibited several phytopathogenic strains of P. viridiflava and P. fluorescens. Based on inhibition zone character and previous genome research we suggest that L-pyocin activity was responsible for this effect against P. viridiflava strains and that tailocin inhibited P. fluorescens isolate.

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9

Moënne-Loccoz, Yvan, Hans-Volker Tichy, Anne O'Donnell, Reinhard Simon y Fergal O'Gara. "Impact of 2,4-Diacetylphloroglucinol-Producing Biocontrol StrainPseudomonas fluorescens F113 on Intraspecific Diversity of Resident Culturable Fluorescent Pseudomonads Associated with the Roots of Field-Grown Sugar Beet Seedlings". Applied and Environmental Microbiology 67, n.º 8 (1 de agosto de 2001): 3418–25. http://dx.doi.org/10.1128/aem.67.8.3418-3425.2001.

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ABSTRACT The impact of the 2,4-diacetylphloroglucinol-producing biocontrol agent Pseudomonas fluorescens F113Rif on the diversity of the resident community of culturable fluorescent pseudomonads associated with the roots of field-grown sugar beet seedlings was evaluated. At 19 days after sowing, the seed inoculant F113Rif had replaced some of the resident culturable fluorescent pseudomonads at the rhizoplane but had no effect on the number of these bacteria in the rhizosphere. A total of 498 isolates of resident fluorescent pseudomonads were obtained and characterized by molecular means at the level of broad phylogenetic groups (by amplified ribosomal DNA restriction analysis) and at the strain level (with random amplified polymorphic DNA markers) as well as phenotypically (55 physiological tests). The introduced pseudomonad induced a major shift in the composition of the resident culturable fluorescentPseudomonas community, as the percentage of rhizoplane isolates capable of growing on three carbon substrates (erythritol, adonitol, and l-tryptophan) not assimilated by the inoculant was increased from less than 10% to more than 40%. However, the pseudomonads selected did not display enhanced resistance to 2,4-diacetylphloroglucinol. The shift in the resident populations, which was spatially limited to the surface of the root (i.e., the rhizoplane), took place without affecting the relative proportions of phylogenetic groups or the high level of strain diversity of the resident culturable fluorescent Pseudomonas community. These results suggest that the root-associatedPseudomonas community of sugar beet seedlings is resilient to the perturbation that may be caused by a taxonomically related inoculant.

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10

MARSHALL, DOUGLAS L. y RONALD H. SCHMIDT. "Growth of Listeria monocytogenes at 10°C in Milk Preincubated with Selected Pseudomonads1". Journal of Food Protection 51, n.º 4 (1 de abril de 1988): 277–82. http://dx.doi.org/10.4315/0362-028x-51.4.277.

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Preliminary studies involving co-inoculation of Listeria monocytogenes with Pseudomonas fragi into whole or skim milk demonstrated that neither inhibition nor stimulation of growth occurred for either organism. Additional investigations involved preincubation of whole milk, skim milk, and 10% reconstituted nonfat dry milk (NDM) for 3 d at 10°C with P. fragi, Pseudomonas fluorescens P26, P. fluorescens T25, or P. fluorescens B52, followed by inoculation with L. monocytogenes and further incubation at 10°C. Growth curves of L. monocytogenes were constructed for each treatment combination and generation times were statistically compared for differences. Results indicated that L. monocytogenes did not affect growth or survival of the preincubated Pseudomonas spp. However, growth rates of L. monocytogenes were significantly (P<0.05) enhanced in milks preincubated with pseudomonads. Doubling times of L. monocytogenes were reduced by up to 3 h when grown in milk preincubated with Pseudomonas spp. Three strains of P. fluorescens showed more stimulation of the growth rate of L. monocytogenes compared to P. fragi in preincubated whole or skim milk but not in preincubated NDM. Milk composition had little effect on growth of either genus when incubated alone. Results of this study indicate that L. monocytogenes can grow in the presence of Pseudomonas spp. either as a co-inoculant or following preincubation in milk at 10°C. Furthermore, data suggest that the presence of the pseudomonads may enhance growth of L. monocytogenes in milk.

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Tesis sobre el tema "Pseudomonas fluorescens"

1

Blankemeier, Andrew R. "Characterization of Pseudomonas fluorescens Biofilm". The Ohio State University, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=osu1307731184.

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2

Hamel, Robert D. "Aluminum detoxification mechanisms in Pseudomonas fluorescens". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/tape16/PQDD_0025/MQ31433.pdf.

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3

Clements, Richard Steven. "The serological homology of Pseudomonas fluorescens proteases". Thesis, Queensland University of Technology, 1987. https://eprints.qut.edu.au/36720/1/36720_Clements_1987.pdf.

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This investigation evaluated the serological homology of proteases from a number of psychotrophic bacteria consisting largely of Pseudomonas_fluorescens strains. Proteases from 4 reference strains of P.fluorescens were purified and rabbit antiserum generated against each. Preliminary investigations revealed the serological heterology of protease OM82 to proteases N73A, M143A and OMl 86. A total of 54, presumably P.fluorescens strains, were grown and semi-pure protease preparations obtained from each. The immunological cross reactivity of 54 semi-pure protease preparations with each of the 4 antisera was evaluated using Ouchterlony Double Diffusion (ODDT), Single Radial Immunodiffusion (SRID) and an Inhibition Enzyme-Linked Immunosorbent Assay (IELISA). The ODDT and IELISA were qualitative tests however, densitometric analysis of SRID precipitin rings enabled cross reaction quantitation in this assay. Each protease was placed into one of 3 enzymo-serogroups according to. the results from each immunological assay. Proteases which did not cross react with any antisera could not be classified. A recent taxonomic study (O'Connor ~t _ gl., 1986) indicated that investigation ~.fluorescens. produced by non several of the enzymes used in this were not produced by strains of It was generally found that proteases P.fluorescens species did not cross react with reference P.fluorescens proteases. Further development of the IELISA increased sensitivity thus, enabling the detection of low nanogram levels of specific proteases in ultra high temperature treated milk. A number of monoclonal antibodies were produced and used to determine whether a common antigenic determinant existed amongst these proteolytic enzymes . Evi dence presented in this study suggests the existence of such an epitope however, the distribution of this determinant amongst the secreted proteases of P . flyore~.Qens is not known .

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4

Wang, Chien-Sao. "Cell-Free Recovery and Isotopic Identification of Cyanide Degrading Enzymes from Pseudomonas Fluorescens". Thesis, University of North Texas, 1995. https://digital.library.unt.edu/ark:/67531/metadc278363/.

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Cell-free extracts from Pseudomonas fluorescens NCIMB 11764 catalyzed the degradation of cyanide into products that included C02, formic acid, formamide and ammonia. Cyanide-degrading activity was localized to cytosolic cell fractions and was observed at substrate concentrations as high as 100 mM. Two cyanide degrading activities were identified by: (i) the determination of reaction products stoichiometries, (ii) requirements for NADH and oxygen, and (iii) kinetic analysis. The first activity produced CO2 and NH3 as reaction products, was dependent on oxygen and NADH for activity, and displayed an apparent Km for cyanide of 1.2 mM. The second activity generated formic acid (and NH3) pfus formamide as reaction products, was oxygen independent, and had an apparent Km of 12 mM for cyanide. The first enzymatic activity was identified as cyanide oxygenase whereas the second activity consists of two enzymes, a cyanide nitrilase (dihydratase) and putative cyanide hydratase. In addition to these enzymes, cyanide-grown cells were also induced for formate dehydrogenase (FDH), providing a means of recycling NADH utilized by cyanide oxygenase.

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5

Levasseur, Rémi. "Aluminum citrate transport and metabolism in Pseudomonas fluorescens". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0018/MQ46489.pdf.

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Wan, Dagang Wan Rosmiza Zana. "Understanding adhesion of Pseudomonas fluorescens on household surfaces". Thesis, University of Birmingham, 2012. http://etheses.bham.ac.uk//id/eprint/3821/.

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In this study, three different methods have been used to investigate the bacterial interaction with the substratum, i.e. atomic force microscopy (AFM), spinning disc and micromanipulation. Pseudomonas fluorescens NCIMB 9046 was chosen as a model microorganism to study the cell-substrate adhesion. By having three different colloidal particles: stainless steel (Grade 304), glass and cellulose, the force measurements were performed in growth medium and ambient air using AFM. The results demonstrated that the adhesive forces were influenced by the surface hydrophobicity, electrostatic, van der Waals and steric interactions. In ambient air, the capillary force played an important role. The effect of shear forces on the bacterial adhesion was further examined. By using an apparatus of spinning disc, the cell removal was strongly influenced by the spinning time, angular velocity and surface hydrophobicity. Finally, the adhesive and cohesive strengths of biofilms were examined via a micromanipulation technique. Results indicate that with pH7 and low initial glucose concentration (0.25% (w/v)) the biofilm adhesion was the greatest among the conditions investigated. The cohesive strength of biofilm was found to depend on on the distance between the force probe and the substrate surface.

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7

Macioszek, Malgorzata. "Biosynthesis of mupirocin by Pseudomonas fluorescens NCIMB 10586". Thesis, University of Birmingham, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.510237.

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Mupirocin, a polyketide antibiotic active against Gram-positive bacteria is used clinically for treatment of bacterial skin infections, to clear Stapylococcus aureus ftom nasal passages and as a surgical scrub to inhibit bacterial growth, particularly that of MRSA. Mupirocin is synthesised by polyketide synthases (PKS) in a series of reactions involving many enzymes encoded by genes from the mupirocin cluster. The mupirocin cluster consists of six larger ORFs (mmpA-F. ) encoding multifunctional proteins, and twenty nine individual genes (mupA-X and macpA-E) all of which have been shown to be required for normal mupirocin biosynthesis and presumably create a biosynthetic assembly line. Sub-groups of mutants produce identical novel metabolites implying the presence of multi-protein complexes. To determine the interactions between proteins of the Mup assembly line Bacterial and Yeast Two Hybrid Systems were used but no evidence has been provided that tested proteins are partners. Although no interaction has been revealed, complementation studies suggest that MupE protein requires coexpression of MupD protein to be functional. Furthermore, inactivation of MupD by amino acid substitution suggests that MupD is not essential on its own for any step in mupirocin biosynthesis except for the proper function of MupE protein. BPLC analysis of wild type P. fluorescens overexpressing mupOlmacpElUIVICIF in trans showed that this did not abolish PA-B production as had been hypothesised but did increase production of total antibiotic (PA-A and PA-B) up to more than two-fold indicating a need to modify our model for the production of PA-B. Results using fluorescence microscopy demonstrate that small Mup proteins are not localized within the bacterial cell and that they are spread evenly in the cells of P. fluorescens.

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8

Frey-Klett, Pascale. "Ecologie d'un pseudomonas fluorescens auxiliaire de la mycorhization". Paris 11, 1996. http://www.theses.fr/1996PA112480.

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La souche de bacterie auxiliaire de la mycorhization pseudomonas fluorescens bbc6, isolee d'un carpophore de laccaria laccata, stimule l'etablissement de la symbiose entre le douglas et ce champignon ectomycorhizien. Dans le but de comprendre son mode d'action mais aussi pour integrer de facon raisonnee son inoculation aux programmes de mycorhization controlee du douglas, nous avons etudie l'ecologie de la souche bbc6 en serre et en pepiniere. Nous avons compare les caracteristiques phenotypiques et genotypiques de bbc6 a celles de 300 souches de pseudomonas fluorescents isolees du sol nu, de la mycorhizosphere et des mycorhizes de douglas-l. Laccata dans un essai en pepiniere. Bbc6 appartient au biovar i des p. Fluorescens et partage des caracteristiques phenotypiques communes a toutes les souches de p. Fluorescens biovar i isolees de la mycorhizosphere et des mycorhizes. Elle est capable d'utiliser le trehalose, sucre majoritairement accumule dans le mycelium de l. Laccata in vitro. Nous avons d'autre part etudie l'ecologie de bbc6 grace a l'utilisation d'un mutant spontane resistant a la rifampicine. La population bacterienne decroit dans le sol et la rhizosphere des semis de douglas apres l'inoculation. La bacterie n'est donc ni tellurique, ni rhizospherique. Elle n'est pas non plus preferentiellement associee aux mycorhizes ni aux carpophores de l. Laccata. Pourtant, la bacterie survit mieux en presence de l. Laccata. La bacterie pourrait donc etre associee au mycelium du champignon dans le sol et profiter des exsudats fongiques, comme le trehalose par exemple. L'effet auxiliaire de la bacterie se manifeste trois a six semaines apres la formation des premieres mycorhizes, lorsque la densite bacterienne a deja chute d'au moins 1000 fois. Il se manifeste egalement pour des doses d'inoculum bacterien aussi faibles que 10 ufc cm#-#3 de sol et permet de diminuer la dose d'inoculum fongique utilisee sans diminuer l'indice de mycorhization des plants

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9

Koza, Anna. "Adaptation and niche construction by Pseudomonas fluorescens SBW25". Thesis, Abertay University, 2011. https://rke.abertay.ac.uk/en/studentTheses/7888a5ac-f562-4518-8124-36d2e394994d.

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The mechanisms underlying adaptive radiation or evolution have been extensively investigated using experimental bacterial populations in liquid cultures, referred to as microcosms. Evolving populations of Pseudomonas fluorescens SBW25 in static microcosms reproducibly lead to the emergence of the Wrinkly Spreader (WS) genotype. These produce a cellulose-matrix-based biofilm to colonise the airliquid (A-L) interface with significant fitness advantage over non-biofilm-forming competitors. In this work, the first SBW25 colonists in static microcosms were shown to establish O₂ gradients, thereby modifying the original environment to establish two new niches corresponding to a high-O₂ region at the A-L interface and a low-O₂ region lower down the liquid column. Greater O₂ availability at the A-L interface was found to provide the selective pressure driving the emergence of the WS and underlay the fitness advantage WS have over non-biofilm-forming strains in this environment. A second biofilm-forming mutant of SBW25, known as the CBFS (Complementary Biofilm Forming Strain), had been previously characterised. Here, wild-type SBW25 was shown to produce a third biofilm-type induced non-specifically by exogenous Fe, and referred to as the viscous mass (VM)-class biofilm. The CBFS, VM and WS biofilm-types could be differentiated by in situ measurements of biofilm attachment and strength, rheometry of biofilm samples, and strain characteristics. However, despite these differences, each provided similar levels of fitness in static microcosms subjected to increasing levels of physical disturbance. This suggests that each of the biofilm-types might arise independently in evolving SBW25 populations as the result of convergent evolution, in which the key ecological constraints are O₂ availability and physical disturbance. However, invasion-from-rare experiments indicated that the WS was ecologically more successful, perhaps explaining why only WS-like genotypes have been isolated from evolving SBW25 populations in static microcosms. Other pseudomonads had previously been shown to produce cellulose-based A-L interface biofilms in static microcosms. Here, a survey of New Zealand brown blotch-causing pseudomonads (BCP) recovered from white mushrooms (Agaricus bisporus) identified similar biofilm-producing, cellulose-expressing isolates. The ability to express cellulose by key BCP isolates was shown to be a fitness advantage in static microcosms, as well as on A. bisporus mushroom caps themselves. Cellulose-expression was also found to be of fitness advantage under water-limiting conditions, suggesting that cellulose may provide some resistance to water-stress in the natural environment. The research undertaken for this Thesis comprise several significant advances in our understanding of the adaptive radiation of P. fluorescens SBW25 and the emergence of A-L interface biofilms in static microcosms. This work has identified O₂ gradients and physical disturbance as the dominant environmental factors that guide the convergent evolution of biofilms in this environment. A consequence of convergent evolution in static microcosms is a variety of physically-different biofilms, all of which provide a fitness advantage over non-biofilm-forming competitors. It is also enlightening to realise that a common structural component of biofilms, cellulose, may also be used in another role to provide a fitness advantage in an ecologically more relevant and natural environment.

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10

Kulkarni, N. "Studies on lipase enzyme from pseudomonas fluorescens NS2W". Thesis(Ph.D.), CSIR-National Chemical Laboratory, Pune, 2002. http://dspace.ncl.res.in:8080/xmlui/handle/20.500.12252/2333.

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Libros sobre el tema "Pseudomonas fluorescens"

1

Yohannes, Berhane. Aluminum efflux in Pseudomonas fluorescens. Sudbury, Ont: Laurentian University, 1997.

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2

Hamel, Robert D. Aluminum detoxification mechanisms in Pseudomonas fluorescens. Sudbury, Ont: Laurentian University, Chemistry and Biochemistry Department, 1997.

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3

Yonis, Abdoulkader. Interaction entre Sélénium et Pseudomonas fluorescens. Sudbury, Ont: Université Laurentienne, 2002.

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Zarghooni, Maryam. Aluminum malate metabolism in Pseudomonas fluorescens. Sudbury, Ont: Laurentian University, 1999.

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Anderson, Shawna. Calcium metabolism in pseudomonas fluorescens ATCC 13525. Sudbury, Ont: Laurentian University, 1991.

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Bédard, Kimberley-Ann. Une pompe active d'aluminium chez Pseudomonas fluorescens. Sudbury, Ont: Université Laurentienne, 1995.

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Levasseur, Rémi. Uptake mechanism of aluminum in "Pseudomonas fluorescens". Sudbury, Ont: Laurentian University, 1997.

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Brewer, Guy. Oxidative stress and valine metabolism in pseudomonas fluorescens. Sudbury, Ont: Laurentian University, 2006.

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Anderson, Shawna. Biochemical adaptation to calcium stress in Pseudomonas fluorescens. Sudbury, Ont: Laurentian University, 1995.

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Levasseur, Rémi. Aluminum-citrate transport and metabolism in Pseudomonas fluorescens. Sudbury, Ont: Laurentian University, Chemistry and Biochemistry Department, 1999.

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Capítulos de libros sobre el tema "Pseudomonas fluorescens"

1

Chew, Lawrence C., Tom M. Ramseier, Diane M. Retallack, Jane C. Schneider, Charles H. Squires y Henry W. Talbot. "Pseudomonas fluorescens". En Production of Recombinant Proteins, 45–66. Weinheim, FRG: Wiley-VCH Verlag GmbH & Co. KGaA, 2005. http://dx.doi.org/10.1002/3527603670.ch3.

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Mavrodi, Dmitri V., Ian T. Paulsen, Qinghu Ren y Joyce E. Loper. "Genomics of Pseudomonas fluorescens Pf-5". En Pseudomonas, 3–30. Dordrecht: Springer Netherlands, 2007. http://dx.doi.org/10.1007/978-1-4020-6097-7_1.

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Zdorovenko, G. M., S. N. Veremeychenko, I. Ya Zakharova y Yu A. Knirel. "Endotoxins of Pseudomonas fluorescens". En Endotoxin, 131–35. Boston, MA: Springer US, 1990. http://dx.doi.org/10.1007/978-1-4757-5140-6_9.

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Kaur, K., T. R. Bott y B. S. C. Leadbeater. "Effect of Ozone on Pseudomonas Fluorescens". En Biofilms — Science and Technology, 589–94. Dordrecht: Springer Netherlands, 1992. http://dx.doi.org/10.1007/978-94-011-1824-8_52.

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Kalita, Prakash Jyoti y Ratul Moni Ram. "Industrial Applications of Pseudomonas fluorescens: A Patent Survey". En Intellectual Property Issues in Microbiology, 383–402. Singapore: Springer Singapore, 2019. http://dx.doi.org/10.1007/978-981-13-7466-1_21.

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Seaton, Sarah Craven y Mark W. Silby. "Genetics and Functional Genomics of the Pseudomonas fluorescens Group". En Genomics of Plant-Associated Bacteria, 99–125. Berlin, Heidelberg: Springer Berlin Heidelberg, 2014. http://dx.doi.org/10.1007/978-3-642-55378-3_5.

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Westphal, A. H., K. Eschrich, W. M. A. M. van Dongen, J. A. E. Benen, A. de Kok y W. J. H. van Berkel. "SITE-DIRECTED MUTAGENESIS OF PARA-HYDROXYBENZOATE HYDROXYLASE FROM PSEUDOMONAS FLUORESCENS". En Flavins and Flavoproteins 1990, editado por B. Curti, S. Ronchi y G. Zanetti, 231–34. Berlin, Boston: De Gruyter, 1991. http://dx.doi.org/10.1515/9783110855425-044.

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Cantore, P. Lo y Nicola Sante Iacobellis. "Head Rot of Cauliflower Caused by Pseudomonas fluorescens in Southern Italy". En Pseudomonas syringae Pathovars and Related Pathogens – Identification, Epidemiology and Genomics, 69–72. Dordrecht: Springer Netherlands, 2008. http://dx.doi.org/10.1007/978-1-4020-6901-7_7.

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Imanaga, Yujiro. "Investigations on the Active Site of Glucose Dehydrogenase from Pseudomonas fluorescens". En PQQ and Quinoproteins, 87–95. Dordrecht: Springer Netherlands, 1989. http://dx.doi.org/10.1007/978-94-009-0957-1_13.

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Panpatte, Deepak G., Yogeshvari K. Jhala, Harsha N. Shelat y Rajababu V. Vyas. "Pseudomonas fluorescens: A Promising Biocontrol Agent and PGPR for Sustainable Agriculture". En Microbial Inoculants in Sustainable Agricultural Productivity, 257–70. New Delhi: Springer India, 2016. http://dx.doi.org/10.1007/978-81-322-2647-5_15.

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Actas de conferencias sobre el tema "Pseudomonas fluorescens"

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Solomiichuk, Michail y Myroslav Pikovskyi. "Bacterium complexes Pseudomonas fluorescens and matters of stimulating nature impact on potato development". En Scientific International Symposium "Plant Protection – Achievements and Perspectives". Institute of Genetics, Physiology and Plant Protection, Republic of Moldova, 2023. http://dx.doi.org/10.53040/ppap2023.75.

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The bacterium strain AP-33 Pseudomonas fluorenscens was the researches subject. The derivatives of ammonium salts of dihydropirymidine did not show toxic action on concentration decrease of viable cells of bacterium strain AP-33 Pseudomonas fluorescens. All biocomplexes combinations showed preparations efficiency against diseases in the scope 59,31-69,63 %. The best yield on potatoes was shown by the combination of AP-33 strain of Pseudomonas fluorescens bacteria, 3x109 CFU/cm3-5 l/ha+0.1% ximedon solution+0.2% succinic acid solution+2 ml of DMAE+2 ml of DMSO, which amounted to 3,4 t/ha. The combination ’s efficiency against late blight consisted of 79,1 %.

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Jannah, Misbahul, Budi Prasetyo, Dharwin Siswanto y Dadik Pantaya. "Pengaruh penambahan bio-emulsifier dari Pseudomonas fluorescens pada pakan terhadap performa broiler". En The 2nd National Conference of Applied Animal Science (CAAS) 2021. Politeknik Negeri Jember, 2021. http://dx.doi.org/10.25047/animpro.2021.4.

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Penelitian ini bertujuan untuk mengetahui pengaruh penambahan Bio-emulsifierdari Pseudomonas fluorescenspada pakan terhadap performabroiler dan mengetahui level terbaik penambahan Bio-emulsifierdari Pseudomonas fluorescenspada pakan broiler. Penelitian ini menggunakan Rancangan Acak Lengkap (RAL) dengan 4 perlakuan dan 5 ulangan. Level Bio-emulsifieryang diberikan yaitu P0 = pakan kontrol tanpa Bio-emulsifier, P1 = 0,5 g/kg pakan, P2 = 1 g/kg pakan, P3 = 1,5 g/kg pakan. Parameter penelitian ini yaitu konsumsi pakan (g/ekor), pertambahan bobot badan (g/ekor) dan konversi pakan. Data dianalisis statistik dengan menggunakan uji Annova. Hasil penelitian ini menunjukan perbedaan nyata (P<0,05) terhadap konsumsi pakan broiler. Kesimpulan dari penelitian ini adalah penambahan Bio-emulsifierdari Pseudomonas fluorescenspada pakan berpengaruh terhadap konsumsi pakan, pada level 0,5 g/kg pakan diperoleh konsumsi pakan rendah yaitu 2026,36 g/ekor dengan nilai konversi pakan sebesar 1,75.

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Ferreira, Irlon M. y André L. M. Porto. "Chemoenzymatic synthesis of derivatives azoles by lipase from Pseudomonas fluorescens". En 15th Brazilian Meeting on Organic Synthesis. São Paulo: Editora Edgard Blücher, 2013. http://dx.doi.org/10.5151/chempro-15bmos-bmos2013_2013914154139.

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Соломийчук, М., О. Панимарчук, В. Кушнир y М. Никорюк. "Сочетание биологического препарата на основе бактерий Pseudomonas Fluorescens и стимулирующих веществ". En International Scientific Symposium "Plant Protection – Achievements and Prospects". Institute of Genetics, Physiology and Plant Protection, Republic of Moldova, 2020. http://dx.doi.org/10.53040/9789975347204.34.

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Derivatives of ammonium salts of dihydropyrimidine did not show a toxic effect on reducing the concentration of viable cells of the bacterium strain AR-33 Pseudomonas fluorescens. The best indicators of the weight of 100 seeds and the number of formed beans in soybeans were shown by the combination Planriz - 5 l / ha + 0.1% solution of xymedon + 0.2% solution of succinic acid + 2 ml of DMAE + 2 ml of DMSO. The use of all combinations of biocomplexes showed the effectiveness of drugs against diseases in the range of 59.31-69.63%. As a result of the use of biocomplexes, their fungicidal, immunoprotective and stimulating action, an increase in yield of 1.15 - 1.7 times relative to control was recorded. The best yield on potatoes showed a combination of Planriz, v.s. (bacteria of strain AP-33 Pseudomonas fluorescens, 3x109 CFU / cm3) - 5 l / ha + 0.1% solution of ximedon + 0.2% solution of succinic acid + 2 ml of DMAE + 2 ml of DMSO, which was 3 , 4 t / ha. The effectiveness of the drug against late blight was 79.1%.

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Shaposhnikov, A. I., N. A. Vishnevskaya, V. Yu Shakhnazarova, D. S. Syrova, E. V. Borodina, O. N. Kovaleva y O. K. Strunnikova. "Features of the initial stages of the relationship between barley, phytopathogenic fungus Fusarium culmorum and rhizobacteria Pseudomonas fluorescens 2137". En 2nd International Scientific Conference "Plants and Microbes: the Future of Biotechnology". PLAMIC2020 Organizing committee, 2020. http://dx.doi.org/10.28983/plamic2020.219.

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It was shown that enhanced colonization of barley's roots by Fusarium culmorum in the presence of Pseudomonas fluorescens 2137 may be due to the composition of root exudates. Strain 2137 can enhance expression of plant defence gene PAL.

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CHRISNAWATI, CHRISNAWATI. "Evaluasi antagonis Pseudomonas fluorescens dalam mengendalikan penyakit layu fusarium pada tomat". En Seminar Nasional Masyarakat Biodiversitas Indonesia. Masyarakat Biodiversitas Indonesia, 2017. http://dx.doi.org/10.13057/psnmbi/m030219.

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Zheleznyakov, S. V., V. K. Lebedeva, T. V. Kalinina, A. P. Kozhemyakov y L. M. Jacobi. "Analysis of Pseudomonas fluorescens inoculation effect on the work of mycorrhiza formed on black medic by arbuscular fungi differing in symbiotic activity". En 2nd International Scientific Conference "Plants and Microbes: the Future of Biotechnology". PLAMIC2020 Organizing committee, 2020. http://dx.doi.org/10.28983/plamic2020.288.

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The influence of rhizobacteria Pseudomonas fluorescens, as well as four species of fungi from the Glomeromycota phylum on the productivity of black medic in mono - and double (fungus + bacteria) inoculation was studied. A high dependence of the results on the symbiotic activity of mycosymbiont was established.

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Sakthipriya, N., M. Doble y Jitendra S. Sangwai. "Enhancement of Flow Assurance by the Degradation of Wax Using Pseudomonas Fluorescens". En Offshore Technology Conference Asia. Offshore Technology Conference, 2016. http://dx.doi.org/10.4043/26380-ms.

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Crucean, Stefan. "Antagonismul bacteriei pseudomonas fluorescens în cadrul controlului biologic al bacteriozei culturii nucifere". En National Scientific Symposium With International Participation: Modern Biotechnologies – Solutions to the Challenges of the Contemporary World. Institute of Microbiology and Biotechnology, Republic of Moldova, 2021. http://dx.doi.org/10.52757/imb21.082.

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Bongers, Q. C. y K. M. Kunisaki. "Strangers in the Lung: A Rare Case of Pseudomonas Fluorescens Complex Pneumonia". En American Thoracic Society 2022 International Conference, May 13-18, 2022 - San Francisco, CA. American Thoracic Society, 2022. http://dx.doi.org/10.1164/ajrccm-conference.2022.205.1_meetingabstracts.a1865.

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Informes sobre el tema "Pseudomonas fluorescens"

1

Daniel P. Molloy. Factors Affecting Zebra Mussel Kill by the Bacterium Pseudomonas fluorescens. Office of Scientific and Technical Information (OSTI), febrero de 2004. http://dx.doi.org/10.2172/876491.

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Frost, John W. Green Synthesis of Phloroglucinol: Exploiting Pseudomonas fluorescens and Scale-Up. Fort Belvoir, VA: Defense Technical Information Center, enero de 2008. http://dx.doi.org/10.21236/ada593488.

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Frost, John W. Green Synthesis of Phloroglucinol: Exploiting Pseudomonas fluorescens and Scale-Up. Fort Belvoir, VA: Defense Technical Information Center, enero de 2010. http://dx.doi.org/10.21236/ada548823.

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Frost, John W. Green Synthesis of Phloroglucinol: Exploiting Pseudomonas fluorescens and Scale-Up. Fort Belvoir, VA: Defense Technical Information Center, enero de 2009. http://dx.doi.org/10.21236/ada548824.

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Frost, John W. Green Synthesis of Phloroglucinol: Exploiting Pseudomonas fluorescens and Scale-Up. Fort Belvoir, VA: Defense Technical Information Center, octubre de 2009. http://dx.doi.org/10.21236/ada548825.

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Daniel Molloy. IMPACT OF SIPHONING ACTIVITY AND NATURALLY SUSPENDED PARTICLE LOAD ON MUSSEL KILL by PSEUDOMONAS FLUORESCENS. Office of Scientific and Technical Information (OSTI), agosto de 2003. http://dx.doi.org/10.2172/822038.

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Daniel P. Molloy. LETHALITY OF PSEUDOMONAS FLUORESCENS STRAIN CLO145A TO THE 2 ZEBRA MUSSEL SPECIES PRESENT IN NORTH AMERICA. Office of Scientific and Technical Information (OSTI), octubre de 2001. http://dx.doi.org/10.2172/811381.

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Thomashow, Linda, Leonid Chernin, Ilan Chet, David M. Weller y Dmitri Mavrodi. Genetically Engineered Microbial Agents for Biocontrol of Plant Fungal Diseases. United States Department of Agriculture, 2005. http://dx.doi.org/10.32747/2005.7696521.bard.

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The objectives of the project were: a) to construct the site-specific integrative expression cassettes carrying: (i) the chiA gene for a 58-kDa endochitinase, (ii) the pyrrolnitrin biosynthesis operon, and (iii) the acdS gene encoding ACC deaminase; b) to employ these constructs to engineer stable recombinant strains with an expanded repertoire of beneficial activities; c) to evaluate the rhizosphere competence and antifungal activity of the WT and modified strains against pathogenic fungi under laboratory and greenhouse conditions; and d) to monitor the persistence and impact of the introduced strains on culturable and nonculturable rhizosphere microbial populations in the greenhouse and the field. The research generally support our concepts that combining strategically selected genes conferring diverse modes of action against plant pathogens into one organism can improve the efficacy of biological control agents. We hypothesized that biocontrol agents (BCAs) engineered to expand their repertoire of beneficial activities will more effectively control soilborne plant pathogens. In this work, we demonstrated that biocontrol activity of Pseudomonas fluorescens Q8r1-96 and Q2-87, both producing the antibiotic 2,4-diacetylphloroglucinol (2,4-DAPG) effective against the plant pathogenic fungus Rhizoctonia solani, can be improved significantly by introducing and expressing either the 1.6-kb gene chiA, encoding the 58-kDa endochitinase ChiA from the rhizosphere strain SerratiaplymuthicaIC1270, or the 5.8-kb prnABCDoperon encoding the broad-range antibiotic pyrrolnitrin (Prn) from another rhizosphere strain, P. fluorescens Pf-5. The PₜₐcchiAandPₜₐcprnABCDcassettes were cloned into the integrative pBK-miniTn7-ΩGm plasmid, and inserted into the genomic DNA of the recipient bacteria. Recombinant derivatives of strains Q8r1-96 and Q2-87 expressing the PₜₐcchiA or PₜₐcprnABCD cassettes produced endochitinase ChiA, or Prn, respectively, in addition to 2,4-DAPG, and the recombinants gave significantly better biocontrol of R. solani on beans under greenhouse conditions. The disease reduction index increased in comparison to the parental strains Q8r1-96 and Q2-87 to 17.5 and 39.0% from 3.2 and 12.4%, respectively, in the case of derivatives carrying the PₜₐcchiAcassette and to 63.1 and 70% vs. 2.8 and 12,4%, respectively, in the case of derivatives carrying the PₜₐcprnABCDcassette. The genetically modified strains exhibited persistence and non-target effects comparable to those of the parental strains in greenhouse soil. Three integrative cassettes carrying the acdS gene encoding ACC deaminase cloned under the control of different promoters were constructed and tested for enhancement of plant growth promotion by biocontrol strains of P. fluorescens and S. plymuthica. The integrative cassettes constructed in this work are already being used as a simple and efficient tool to improve biocontrol activity of various PGPR bacteria against fungi containing chitin in the cell walls or highly sensitive to Prn. Some parts of the work (e. g., construction of integrative cassettes) was collaborative while other parts e.g., (enzyme and antibiotic activity analyses) were fully synergistic. The US partners isolated and provided to the Israeli collaborators the original biocontrol strains P. fluorescens strains Q8r1-96 and Q2-87 and their mutants deficient in 2,4-DAPG production, which were used to evaluate the relative importance of introduction of Prn, chitinase or ACC deaminase genes for improvement of the biocontrol activity of the parental strains. The recombinant strains obtained at HUJI were supplied to the US collaborators for further analysis.

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Lindow, Steven E., Shulamit Manulis, Dan Zutra y Dan Gaash. Evaluation of Strategies and Implementation of Biological Control of Fire Blight. United States Department of Agriculture, julio de 1993. http://dx.doi.org/10.32747/1993.7568106.bard.

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The main objective of this study was to develop data that would facilitate a consistently effective method of biological control of fire blight disease to be developed and to enable its implementation for disease control by ensuring its compatibility with variations in the biological, environmental, and chemical conditions present in pear orchards. As considerable information on the pathogen and biological control of fire blight was already gathered from studies in California and elsewhere, an emphasis was placed on investigating the genetics and ecology of Erwinia amylovora, the causal agent of fire blight in Israel. Studies of plasmid profile, virulence on several host, serological characteristics, as well as DNA fingerprints with selected primers all revealed E. amylovora strains in Israel to be homogeneous. Strains did vary in their resistance to streptomycin, with those from more northern locations being resistant while those in the southern costal plain were all sensitive to streptomycin. Resistance appeared to be conferred by chromosomal mutations as in streptomycin-resistant strains in California. The biological control agent Pseudomonas fluorescens strain A506 colonized flowers of both the Costia and Spodona pear cultivars in Israel as well as Bartlett pear in California. Flowers that were open at the time of spray inoculation of trees subsequently harbored from 105 to 107 cells of strain A506 per flower, while those that opened subsequent to spraying developed population sizes of about 105 cells/flower within 5 days. The incidence of fire blight infections were reduced about 3-fold in several trials in which moderate amounts of disease occurred in the plot areas; this degree of biological control is similar to that observed in California and elsewhere. On two occasions warm and moist weather that favored disease led to epidemics in which nearly all flowers became infected and which was so severe that neither P. fluorescens strain A506 nor chemical bactericides reduced disease incidence. A novel method for identifying antagonistic microorganisms for biological control of fire blight and other diseases was developed. A bacterial ice nucleation gene was introduced into E. amylovora to confer an Ice+ phenotype and the population sizes of this modified pathogen on flowers that had been pre-treated with potential control agents was estimated by measuring the freezing temperature of colonized flowers. Antagonistic strains that prevented the growth of E. amylovora in flowers were readily detected as those in which flowers froze at a low temperature. The method is both rapid and unbiased and several bacterial strains with substantial biological control potential have been identified using this method.

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Chen, Yona, Jeffrey Buyer y Yitzhak Hadar. Microbial Activity in the Rhizosphere in Relation to the Iron Nutrition of Plants. United States Department of Agriculture, octubre de 1993. http://dx.doi.org/10.32747/1993.7613020.bard.

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Iron is the fourth most abundant element in the soil, but since it forms insoluble hydroxides at neutral and basic pH, it often falls short of meeting the basic requirements of plants and microorganisms. Most aerobic and facultative aerobic microorganisms possess a high-affinity Fe transport system in which siderophores are excreted and the consequent Fe complex is taken up via a cognate specific receptor and a transport pathway. The role of the siderophore in Fe uptake by plants and microorganisms was the focus of this study. In this research Rhizopus arrhizus was found to produce a novel siderophore named Rhizoferrin when grown under Fe deficiency. This compound was purified and its chemical structure was elucidated. Fe-Rhizoferrin was found to alleviate Fe deficiency when applied to several plants grown in nutrient solutions. It was concluded that Fe-Rhizoferrin is the most efficient Fe source for plants when compared with other among microbial siderophores known to date and its activity equals that of the most efficient synthetic commercial iron fertilizer-Fe EDDHA. Siderophores produced by several rhizosphere organisms including Rhizopus Pseudomonas were purified. Monoclonal antibodies were produced and used to develop a method for detection of the siderophores produced by plant-growth-promoting microorganisms in barley rhizosphere. The presence of an Fe-ferrichrome uptake in fluorescent Pseudomonas spp. was demonstrated, and its structural requirements were mapped in P. putida with the help of biomimetic ferrichrome analogs. Using competition experiments, it was shown that FOB, Cop B and FC share at least one common determinant in their uptake pathway. Since FC analogs did not affect FOB or Cop-mediated 55Fe uptake, it could be concluded that these siderophores make use of a different receptor(s) than FC. Therefore, recognition of Cop, FOB and FC proceeds through different receptors having different structural requirements. On the other hand, the phytosiderophores mugineic acid (MA and DMA), were utilized indirectly via ligand exchange by P. putida. Receptors from different biological systems seem to differ in their structural requirements for siderophore recognition and uptake. The design of genus- or species-specific drugs, probes or chemicals, along with an understanding of plant-microbe and microbe-microbe relationships as well as developing methods to detect siderophores using monoclonal antibodies are useful for manipulating the composition of the rhizosphere microbial population for better plant growth, Fe-nutrition and protection from diseases.

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