title: Structure determination of the exopolysaccharide of Lactobacillus fermentum TDS030603-a revision.
abstract: The highly viscous neutral exopolysaccharide, produced in large amounts by Lactobacillus fermentum TDS030603 in MRS broth and in a chemically defined medium supplemented with glucose, was investigated by GLC(-EIMS) monosaccharide and methylation analysis, periodate oxidation, MALDI-TOF mass spectrometry, and 1D/2D NMR spectroscopy. The GLC(-EIMS) analyses showed that the EPS contained d-glucose and d-galactose in an averaged molar ratio of 2.6:1.0, consisting of terminal d-Glcp, 3-substituted d-Glcp, 2,3-disubstituted d-Glcp, and 6-substituted d-Galp in an averaged molar ratio of 1.3:1.0:1.1:1.1, with a trace of terminal d-Galp (0.1). Combined with the NMR data of the EPS (previously reported constituent analysis: terminal Glcp, 3-substituted Glcp, 2,3-disubstituted Glcp, and 6-substituted Galp in an averaged molar ratio of 1.2:1.1:1.0:1.1) and oligosaccharides isolated after partial acid hydrolysis, a branched tetrasaccharide repeating unit, with some heterogeneity in the side chain, having the following structure is proposed: [fromula see text].
authors.affiliation: NMR Spectroscopy, Bijvoet Center, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands. g.gerwig@rug.nl
authors.forename: Gerrit J
authors.initials: GJ
authors.lastname: Gerwig
authors.forename: Justyna M
authors.initials: JM
authors.lastname: Dobruchowska
authors.forename: Tala
authors.initials: T
authors.lastname: Shi
authors.forename: Tadasu
authors.initials: T
authors.lastname: Urashima
authors.forename: Kenji
authors.initials: K
authors.lastname: Fukuda
authors.forename: Johannis P
authors.initials: JP
authors.lastname: Kamerling
mesh_terms: D002240:Carbohydrate Sequence; D006868:Hydrolysis; D052197:Limosilactobacillus fermentum / Q000737:chemistry*; D008745:Methylation; D008969:Molecular Sequence Data; D009005:Monosaccharides / Q000737:chemistry; D010084:Oxidation-Reduction; D010504:Periodic Acid / Q000737:chemistry; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D009005:Monosaccharides; D011135:Polysaccharides, Bacterial; D010504:Periodic Acid; C009288:metaperiodate
keywords: Exopolysaccharide; Lactic acid bacteria; Lactobacillus fermentum; NMR spectroscopy; Structural analysis