title: To settle or to move? The interplay between two classes of cyclic lipopeptides in the biocontrol strain Pseudomonas CMR12a.
abstract: Pseudomonas CMR12a is a biocontrol strain that produces phenazine antibiotics and as yet uncharacterized cyclic lipopeptides (CLPs). The CLPs of CMR12a were studied by chemical structure analysis and in silico analysis of the gene clusters encoding the non-ribosomal peptide synthetases responsible for CLP biosynthesis. CMR12a produces two different classes of CLPs: orfamides B, D and E, whereby the latter two represent new derivatives of the orfamide family, and sessilins A-C. The orfamides are made up of a 10 amino acid peptide coupled to a β-hydroxydodecanoyl or β-hydroxytetradecanoyl fatty acid moiety, and are related to orfamides produced by biocontrol strain Pseudomonas protegens Pf-5. The sessilins consist of an 18-amino acid peptide linked to a β-hydroxyoctanoyl fatty acid and differ in one amino acid from tolaasins, toxins produced by the mushroom pathogen Pseudomonas tolaasii. CLP biosynthesis mutants were constructed and tested for biofilm formation and swarming motility. Orfamides appeared indispensable for swarming while sessilin mutants showed reduced biofilm formation, but enhanced swarming motility. The interplay between the two classes of CLPs fine tunes these processes. The presence of sessilins in wild type CMR12a interferes with swarming by hampering the release of orfamides and by co-precipitating orfamides to form a white line in agar.
authors.affiliation: Laboratory of Phytopathology, Faculty of Bioscience Engineering, Ghent University, Ghent, Belgium.
authors.forename: Jolien
authors.initials: J
authors.lastname: D'aes
authors.forename: Nam Phuong
authors.initials: NP
authors.lastname: Kieu
authors.forename: Valérie
authors.initials: V
authors.lastname: Léclère
authors.forename: Caroline
authors.initials: C
authors.lastname: Tokarski
authors.forename: Feyisara Eyiwumi
authors.initials: FE
authors.lastname: Olorunleke
authors.forename: Katrien
authors.initials: K
authors.lastname: De Maeyer
authors.forename: Philippe
authors.initials: P
authors.lastname: Jacques
authors.forename: Monica
authors.initials: M
authors.lastname: Höfte
authors.forename: Marc
authors.initials: M
authors.lastname: Ongena
mesh_terms: D000362:Agar; D001426:Bacterial Proteins / Q000737:chemistry; D018441:Biofilms / Q000254:growth & development*; D061046:Biological Control Agents; D047630:Depsipeptides / Q000737:chemistry; D015964:Gene Expression Regulation, Bacterial; D055666:Lipopeptides / Q000096:biosynthesis* / Q000235:genetics; D009068:Movement; D005810:Multigene Family; D009154:Mutation; D010453:Peptide Synthases / Q000235:genetics* / Q000378:metabolism; D010456:Peptides, Cyclic / Q000096:biosynthesis* / Q000235:genetics; D010619:Phenazines / Q000378:metabolism; D011549:Pseudomonas / Q000235:genetics* / Q000378:metabolism
chemical_list: D001426:Bacterial Proteins; D061046:Biological Control Agents; D047630:Depsipeptides; D055666:Lipopeptides; D010456:Peptides, Cyclic; D010619:Phenazines; C067241:tolaasin protein, Pseudomonas tolaasii; D000362:Agar; D010453:Peptide Synthases