title: 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine, an effective peptide antibiotic from the epiphyte Pantoea agglomerans 48b/90.
abstract: The epiphyte Pantoea agglomerans 48b/90, which has been isolated from soybean leaves, belongs to the Enterobacteriaceae, as does the plant pathogen Erwinia amylovora, which causes fire blight on rosaceous plants such as apples and leads to severe economic losses. Since P. agglomerans efficiently antagonizes phytopathogenic bacteria, the P. agglomerans strain C9-1 is used as a biocontrol agent (BlightBan C9-1). Here we describe the bioassay-guided isolation of a peptide antibiotic that is highly active against the plant pathogen E. amylovora and pathovars of Pseudomonas syringae, and we elucidate its structure. Bioassay-guided fractionation using anion-exchange chromatography followed by hydrophobic interaction liquid chromatography yielded the bioactive, highly polar antibiotic. The compound was identified as 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine by using high-resolution electrospray ionization mass spectrometry and nuclear magnetic resonance techniques. This peptide was found to be produced by three of the nine P. agglomerans strains analyzed. Notably, the biocontrol strain P. agglomerans C9-1 also produces 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine. Previously, 2-amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine has been characterized only from Serratia plymuthica. 2-Amino-3-(oxirane-2,3-dicarboxamido)-propanoyl-valine has been shown to inhibit the growth of the human pathogen Candida albicans efficiently, but its involvement in the defense of epiphytes against phytopathogenic bacteria has not been investigated so far.
authors.affiliation: Institut für Mikrobiologie, Mikrobielle Phytopathologie, Friedrich-Schiller-Universität Jena, Neugasse 25, D-07743 Jena, Germany.
authors.forename: Ulrike F
authors.initials: UF
authors.lastname: Sammer
authors.forename: Beate
authors.initials: B
authors.lastname: Völksch
authors.forename: Ute
authors.initials: U
authors.lastname: Möllmann
authors.forename: Michaela
authors.initials: M
authors.lastname: Schmidtke
authors.forename: Peter
authors.initials: P
authors.lastname: Spiteller
authors.forename: Michael
authors.initials: M
authors.lastname: Spiteller
authors.forename: Dieter
authors.initials: D
authors.lastname: Spiteller
mesh_terms: D000900:Anti-Bacterial Agents / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D023181:Antimicrobial Cationic Peptides; D001431:Bacteriological Techniques; D044084:Erwinia amylovora / Q000187:drug effects; D006801:Humans; D008826:Microbial Sensitivity Tests; D020636:Pantoea / Q000737:chemistry*; D010455:Peptides / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology; D010935:Plant Diseases / Q000235:genetics / Q000382:microbiology; D044224:Pseudomonas syringae / Q000187:drug effects; D012705:Serratia / Q000187:drug effects / Q000235:genetics; D013025:Glycine max / Q000382:microbiology
chemical_list: C548064:2-amino-3-(oxirane-2,3-dicarboxamido)propanoylvaline; D000900:Anti-Bacterial Agents; D023181:Antimicrobial Cationic Peptides; D010455:Peptides