title: In situ localisation and quantification of surfactins in a Bacillus subtilis swarming community by imaging mass spectrometry.
abstract: Surfactins are a family of heptacyclopeptides in which the C-terminal carbonyl is linked with the beta-hydroxy group of a fatty acid acylating the N-terminal function of a glutamic acid residue. The fatty acyl chain is 12-16 carbon atoms long. These compounds, which are secreted by the Gram-positive bacterium Bacillus subtilis in stationary phase in liquid cultures, play an important role in swarming communities on the surface of agar media in the formation of dendritic patterns. TOF secondary ion MS (TOF-SIMS) imaging was used to map surfactins within 16-17 h swarming patterns, with a 2 mum spatial resolution. Surfactins were mainly located in the central mother colony (the site of initial inoculation), in a 'ring' surrounding the pattern and along the edges of the dendrites. In the mother colony and the interior of the dendrites, surfactins with shorter chain lengths are present, whereas in the ring surrounding the swarm community and between dendrites, surfactins with longer fatty acyl chain lengths were found. A quantitative analysis by MALDI-TOF MS showed a concentration gradient of surfactin from the mother colony to the periphery. The concentration of surfactin was approximately 400 pmol/mL in the mother colony and approximately 10 pmol/mL at the base of the dendrites, decreasing to 2 pmol/mL at their tips.
authors: Institut de Chimie des Substances Naturelles, CNRS, UPR 2301, Av. de la Terrasse, Gif-sur-Yvette, France.
authors: Delphine
authors: D
authors: Debois
authors: Kassem
authors: K
authors: Hamze
authors: Vincent
authors: V
authors: Guérineau
authors: Jean-Pierre
authors: JP
authors: Le Caër
authors: I Barry
authors: IB
authors: Holland
authors: Philippe
authors: P
authors: Lopes
authors: Jamal
authors: J
authors: Ouazzani
authors: Simone J
authors: SJ
authors: Séror
authors: Alain
authors: A
authors: Brunelle
authors: Olivier
authors: O
authors: Laprévote
mesh_terms: D001412:Bacillus subtilis / Q000378:metabolism*; D001426:Bacterial Proteins / Q000032:analysis*; D055666:Lipopeptides / Q000032:analysis*; D010456:Peptides, Cyclic / Q000032:analysis*; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D001426:Bacterial Proteins; D055666:Lipopeptides; D010456:Peptides, Cyclic; C009365:surfactin peptide