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A Novel Antifungal Pseudomonas fluorescens Isolated from Potato Soils in Greenland


A rhizobacterium with high antifungal activity was isolated from a potato field at Inneruulalik, South Greenland. Phylogenetic analysis based on multi locus sequence typing showed that the bacterium was affiliated with strains of Pseudomonas fluorescens. The bacterium, denoted as Pseudomonas fluorescens In5, inhibited in vitro a broad range of phytopathogenic fungi, and the antifungal activity increased with decreasing temperature. Microcosm experiments demonstrated that P. fluorescens In5 protected tomato seedlings from Rhizoctonia solani. Transposon mutagenesis showed that the major cause for the antifungal activity of P. fluorescens In5 was a novel non-ribosomal peptide synthase (NRPS) gene. In addition, transposon mutagenesis showed that P. fluorescens In5 also contained a putative quinoprotein glucose dehydrogenase gene, which was involved in growth inhibition of phytopathogenic fungi. Although P. fluorescens In5 contained the capacity to synthesize hydrogen cyanide, β-1,3-glucanase, protease, and chitinase, these did not seem to play a role in the in vitro and microcosm antifungal assays.

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  1. 1.

    Abbas A, Morrissey JP, Marquez PC, Sheehan MM, Delany IR, O’Gara F (2002) Characterization of interactions between the transcriptional repressor PhlF and its binding site at the phlA promoter in Pseudomonas fluorescens F113. J Bacteriol 11:3008–3016

    Article  Google Scholar 

  2. 2.

    Ajit NS, Verma R, Shanmugam V (2006) Extracellular chitinases of fluorescent pseudomonads antifungal to Fusarium oxysporum f. sp dianthi causing carnation wilt. Curr Microbiol 4:310–316

    Article  Google Scholar 

  3. 3.

    Anzai Y, Kim H, Park JY, Wakabayashi H, Oyaizu H (2000) Phylogenetic affiliation of the pseudomonads based on 16S rRNA sequence. Int J Syst Evol Microbiol 50(Pt4):1563–1589

    Google Scholar 

  4. 4.

    Arora NK, Khare E, Oh JH, Kang SC, Maheshwari DK (2008) Diverse mechanisms adopted by fluorescent Pseudomonas PGC2 during the inhibition of Rhizoctonia solani and Phytophthora capsici. World J Microbiol Biotechnol 4:581–585

    Article  Google Scholar 

  5. 5.

    Aziz RK, Bartels D, Best AA, DeJongh M, Disz T, Edwards RA, Formsma K, Gerdes S, Glass EM, Kubal M, Meyer F, Olsen GJ, Olson R, Osterman AL, Overbeek RA, Mcneil LK, Paarmann D, Paczian T, Parrello B, Pusch GD, Reich C, Stevens R, Vassieva O, Vonstein V, Wilke A et al (2008) The RAST server: rapid annotations using subsystems technology. BMC Genomics 9:75

  6. 6.

    Baker KF, Cook RJ (1974) Biological control of plant pathogens. Freedman and company, San Francisco, 433 pp

  7. 7.

    Bangera MG, Thomashow LS (1999) Identification and characterization of gene cluster for synthesis of the polyketide antibiotic 2, 4-diacetylphloroglucinol from Pseudomonas fluorescens Q2–87. J Bacteriol 10:3155–3163

    Google Scholar 

  8. 8.

    Blumer C, Haas D (2000) Iron regulation of the hcnABC genes encoding hydrogen cyanide synthase depends on the anaerobic regulator ANR rather than on the global activator GacA in Pseudomonas fluorescens CHA0. Microbiology Sgm 146:2417–2424

    Google Scholar 

  9. 9.

    Case RJ, Boucher Y, Dahllof I, Holmstrom C, Doolittle WF, Kjelleberg S (2007) Use of 16S rRNA and rpoB genes as molecular markers for microbial ecology studies. Appl Environ Microbiol 1:278–288

    Article  Google Scholar 

  10. 10.

    de Bruijn I, de Kock MJD, Yang M, de Waard P, van Beek TA, Raaijmakers JM (2007) Genome-based discovery, structure prediction and functional analysis of cyclic lipopeptide antibiotics in Pseudomonas species. Mol Microbiol 2:417–428

    Google Scholar 

  11. 11.

    de Souza JT, Raaijmakers JM (2003) Polymorphisms within the prnD and pltC genes from pyrrolnitrin and pyoluteorin-producing Pseudomonas and Burkholderia spp. FEMS Microbiol Ecol 1:21–34

    Google Scholar 

  12. 12.

    de Werra P, Pechy-Tarr M, Keel C, Maurhofer M (2009) Role of gluconic acid production in the regulation of biocontrol traits of Pseudomonas fluorescens CHA0. Appl Environ Microbiol 12:4162–4174

    Article  Google Scholar 

  13. 13.

    Delaney SM, Mavrodi DV, Bonsall RF, Thomashow LS (2001) phzO, a gene for biosynthesis of 2-hydrolyated phenazine compounds in Pseudomonas aureofaciens 30-84. J Bacteriol 1:318–327

    Article  Google Scholar 

  14. 14.

    Dennis JJ, Zylstra GJ (1998) Plasposons: modular self-cloning minitransposon derivatives for rapid genetic analysis of gram-negative bacterial genomes. Appl Environ Microbiol 7:2710–2715

    Google Scholar 

  15. 15.

    Doolittle WF (1999) Phylogenetic classification and the universal tree. Science 5423:2124–2128

    Article  Google Scholar 

  16. 16.

    Frapolli M, Defago G, Moenne-Loccoz Y (2007) Multilocus sequence analysis of biocontrol fluorescent Pseudomonas spp. producing the antifungal compound 2,4-diacetylphloroglucinol. Environ Microbiol 8:1939–1955

    Article  Google Scholar 

  17. 17.

    Guo YB, Li JY, Li L, Chen F, Wu WL, Wang JH, Wang HM (2009) Mutations that disrupt either the pqq or the gdh gene of Rahnella aquatilis abolish the production of an antibacterial substance and result in reduced biological control of grapevine crown gall. Appl Environ Microbiol 21:6792–6803

    Article  Google Scholar 

  18. 18.

    Haas D, Defago G (2005) Biological control of soil-borne pathogens by fluorescent pseudomonads. Nat Rev Microbiol 4:307–319

    Article  Google Scholar 

  19. 19.

    Hammer PE, Hill DS, Lam ST, Vanpee KH, Ligon JM (1997) Four genes from Pseudomonas fluorescens that encode the biosynthesis of pyrrolnitrin. Appl Environ Microbiol 6:2147–2154

    Google Scholar 

  20. 20.

    Kavitha K, Mathiyazhagan S, Sendhilvel V, Nakeeran S, Chandrasekar G, Fernando WG (2005) Broad spectrum action of phenazine against active and dormant structures of fungal pathogens and root knot nematode. Arch Phytopathol Plant Prot 1:69–76

    Article  Google Scholar 

  21. 21.

    Kay E, Dubuis C, Haas D (2005) Three small RNAs jointly ensure secondary metabolism and biocontrol in Pseudomonas fluorescens CHA0. Proc Natl Acad Sci USA 47:17136–17141

    Article  Google Scholar 

  22. 22.

    Laville J, Blumer C, Von Schroetter C, Gaia V, Defago G, Keel C, Haas D (1998) Characterization of the hcnABC gene cluster encoding hydrogen cyanide synthase and anaerobic regulation by ANR in the strictly aerobic biocontrol agent Pseudomonas fluorescens CHAO. J Bacteriol 12:3187–3196

    Google Scholar 

  23. 23.

    Laville J, Voisard C, Keel C, Maurhofer M, Defago G, Haas D (1992) Global control in Pseudomonas fluorescens mediating antibiotic synthesis and suppression of black root-rot of tobacco. Proc Natl Acad Sci USA 5:1562–1566

    Article  Google Scholar 

  24. 24.

    Lemanceau P, Alabouvette C (1991) Biological control of Fusarium diseases by fluorescent Pseudomonas and nonpathogenic Fusarium. Crop Prot 4:279–286

    Article  Google Scholar 

  25. 25.

    Maiden MCJ, Bygraves JA, Feil E, Morelli G, Russell JE, Urwin R, Zhang Q, Zhou JJ, Zurth K, Caugant DA, Feavers IM, Achtman M, Spratt BG (1998) Multilocus sequence typing: a portable approach to the identification of clones within populations of pathogenic microorganisms. Proc Natl Acad Sci USA 6:3140–3145

    Article  Google Scholar 

  26. 26.

    Mavrodi DV, Bonsall RF, Delaney SM, Soule MJ, Phillips G, Thomashow LS (2001) Functional analysis of genes for biosynthesis of pyocyanin and phenazine-1-carboxamide from Pseudomonas aeruginosa PAO1. J Bacteriol 21:6454–6465

    Article  Google Scholar 

  27. 27.

    Paulsen IT, Press CM, Ravel J, Kobayashi DY, Myers GSA, Mavrodi DV, Deboy RT, Seshadri R, Ren QH, Madupu R, Dodson RJ, Durkin AS, Brinkac LM, Daugherty SC, Sullivan SA, Rosovitz MJ, Gwinn ML, Zhou LW, Schneider DJ, Cartinhour SW, Nelson WC, Weidman J, Watkins K, Tran K, Khouri H et al (2005) Complete genome sequence of the plant commensal Pseudomonas fluorescens Pf-5. Nat Biotechnol 7:873–878

    Article  Google Scholar 

  28. 28.

    R Development Core Team (2009) R: a language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria

  29. 29.

    Raaijmakers JM, Vlami M, de Souza JT (2002) Antibiotic production by bacterial biocontrol agents. Antonie Van Leeuwenhoek Int J Gen Mol Microbiol 1–4:537–547

    Article  Google Scholar 

  30. 30.

    Reasoner DJ, Geldreich EE (1985) A new medium for the enumeration and subculture of bacteria from potable water. Appl Environ Microbiol 1:1–7

    Google Scholar 

  31. 31.

    Sambrook J, Russel DW (2001) Molecular cloning: a laboratory manual, 3rd edn. Cold Spring Harbor Laboratory, Cold Spring Harbor

    Google Scholar 

  32. 32.

    Sivan A, Chet I (1989) The possible role of competition between Trichoderma harzianum and Fusarium oxysporum on rhizosphere colonization. Phytopathology 2:198–203

    Article  Google Scholar 

  33. 33.

    Svercel M, Duffy B, Defago G (2007) PCR amplification of hydrogen cyanide biosynthetic locus hcnAB in Pseudomonas spp. J Microbiol Meth 1:209–213

    Article  Google Scholar 

  34. 34.

    Trieucuot P, Derlot E, Courvalin P (1993) Enhanced conjugative transfer of plasmid DNA from Escherichia coli to Staphylococcus aureus and Listeria monocytogenes. FEMS Microbiol Lett 1:19–24

    Article  Google Scholar 

  35. 35.

    Weller DM, Raaijmakers JM, Gardener BBM, Thomashow LS (2002) Microbial populations responsible for specific soil suppressiveness to plant pathogens. Annu Rev Phytopathol 40:309–348

    Google Scholar 

  36. 36.

    Whipps JM (1987) Effect of media on growth and interactions between a range of soil-borne glasshouse pathogens and antagonistic fungi. New Phytol 1:127–142

    Article  Google Scholar 

  37. 37.

    Yen YH, Li PL, Wang CL, Wang SL (2006) An antifungal protease produced by Pseudomonas aeruginosa M-1001 with shrimp and crab shell powder as a carbon source. Enzym Microb Technol 2:311–317

    Article  Google Scholar 

  38. 38.

    Yuen GY, Schroth MN (1986) Inhibition of Fusarium oxysporum f. sp. dianthi by iron competition with an Alcaligenes sp. Phytopathology 2:171–176

    Article  Google Scholar 

  39. 39.

    Zerbino DR, Birney E (2008) Velvet: algorithms for de novo short read assembly using de Bruijn graphs. Genome Res 5:821–829

    Article  Google Scholar 

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We thank chief counselor Kenneth Høegh, Qaqortoq, Greenland, for support during sampling of material and research in Greenland. Anders Priemé and Martin Asser Hansen are thanked for establishing the near-whole genome sequence of strain In5. Eigil de Neergaard, Danish Plant Directorate and Lisa Munk, University of Copenhagen, are acknowledged for communicating unpublished data on the occurrence of fungal pathogens in Greenland. Referring to the Convention on Biological Diversity, we thank the Greenland Home Rule for permission to sample bacteria in South Greenland. This work was funded in part by the Commission for Scientific Research in Greenland.

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Correspondence to Peter Stougaard.

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Michelsen, C.F., Stougaard, P. A Novel Antifungal Pseudomonas fluorescens Isolated from Potato Soils in Greenland. Curr Microbiol 62, 1185–1192 (2011).

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  • Antifungal Activity
  • Chitinase
  • Graminearum
  • Pseudomonas Fluorescens
  • Phytopathogenic Fungus