title: Purification and structural data of a highly substituted exopolysaccharide from Pseudomonas stutzeri AS22.
abstract: Pseudomonas stutzeri AS22, when grown on media containing starch and yeast extract and incubated at 30 °C and 200 rpm for 24h, was found to produce an acidic and high-molecular mass exopolysaccharide (EPS22). The EPS22 was purified and a yield of 1.3g/l was achieved. The average molecular mass of the EPS22 was determined by high-performance size-exclusion chromatography (HPSEC) and showed an average molecular mass of 9.9 × 10(5)Da and a polydispersity index Mw/Mn (Mw, weight-average and Mn, number-average) of 1.197 ± 0.015. Structural data of this EPS22 were determined using a combination approach including monosaccharide composition (HPAEC-PAD and GLC), methylation analysis (GC-MS) and NMR spectroscopy analysis. EPS22 was found to be a complex heteropolysaccharide with a repeating unit mainly composed of glucose, mannose and lactyl rhamnose in a molar ratio of 1:1.1:0.7. The acidic nature of the polysaccharide is due to the presence of three non-osidic substituents consisting of a lactyl, acetyl, and pyruvyl groups.
authors.affiliation: Laboratory of Enzyme Engineering and Microbiology, Sfax-University, National School of Engineering of Sfax (ENIS), BP 1173, Sfax 3038, Tunisia.
authors.forename: Hana
authors.initials: H
authors.lastname: Maalej
authors.affiliation: Centre de Recherches sur les Macromolécules Végétales, C.N.R.S., Université Joseph Fourier, BP 53, Grenoble Cedex 9 38041, France.
authors.forename: Claire
authors.initials: C
authors.lastname: Boisset
authors.affiliation: Laboratory of Enzyme Engineering and Microbiology, Sfax-University, National School of Engineering of Sfax (ENIS), BP 1173, Sfax 3038, Tunisia. Electronic address: hmidet_noomen@yahoo.fr.
authors.forename: Noomen
authors.initials: N
authors.lastname: Hmidet
authors.affiliation: Centre de Recherches sur les Macromolécules Végétales, C.N.R.S., Université Joseph Fourier, BP 53, Grenoble Cedex 9 38041, France.
authors.forename: Laurine
authors.initials: L
authors.lastname: Buon
authors.affiliation: Centre de Recherches sur les Macromolécules Végétales, C.N.R.S., Université Joseph Fourier, BP 53, Grenoble Cedex 9 38041, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Heyraud
authors.affiliation: Laboratory of Enzyme Engineering and Microbiology, Sfax-University, National School of Engineering of Sfax (ENIS), BP 1173, Sfax 3038, Tunisia.
authors.forename: Moncef
authors.initials: M
authors.lastname: Nasri
mesh_terms: D002236:Carbohydrate Conformation; D005947:Glucose / Q000737:chemistry; D006868:Hydrolysis; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000302:isolation & purification; D044223:Pseudomonas stutzeri / Q000737:chemistry*; D012210:Rhamnose / Q000032:analysis
chemical_list: D011135:Polysaccharides, Bacterial; D005947:Glucose; D012210:Rhamnose
keywords: Exopolysaccharide EPS22; High molecular mass; Pseudomonas stutzeri AS22; Purification; Structural data