Structural characterization of the exocellular polysaccharides produced by Streptococcus thermophilus SFi39 and SFi12

Article Article scientifique Article Structural characterization of the exocellular polysaccharides produced by Streptococcus thermophilus SFi39 and SFi12 eng 1997 author Lemoine Jérôme author Chirat Frédéric author Wieruszeski Jean-Michel author Strecker Gérard author Favre Nicole 716243 author Neeser Jean-Richard 25568 3512-3518 10.1128/aem.63.9.3512-3518.1997 9293002 0099-2240 We investigated the structures of the exopolysaccharides (EPSs) produced by Streptococcus thermophilus SFi39 and SFi12. Both polymers were found to have molecular masses of greater than 2 x 10(6) Da. The SFi39 EPS consisted of D-glucose and D-galactose in a molar ratio of 1:1, whereas the SFi12 EPS was composed of D-galactose, L-rhamnose, and D-glucose in a molar ratio of 3:2:1. Methylation analysis of and nuclear magnetic resonance spectra recorded from the native polysaccharide, as well as oligosaccharides released by partial acid hydrolysis, allowed the complete structural determination of the SFi39 EPS, which consists of the following tetrasaccharide repeating unit: [formula: see text] Similar spectra recorded only from the native polysaccharide were sufficient to allow the structural determination of the SFi12 EPS, which consists of the following hexasaccharide repeating unit: [formula: see text] This study shows that the texturizing properties of different S. thermophilus ropy strains are based on the production of EPSs exhibiting chemical similarities but structural differences. Carbohydrate Conformation Carbohydrate Sequence Magnetic Resonance Spectroscopy Molecular Sequence Data Molecular Structure Molecular Weight Polysaccharides Bacterial/biosynthesis/chemistry Species Specificity Streptococcus/chemistry/metabolism true Applied and environmental microbiology 63 9 720740ad-8ddb-4d6f-8180-47419a576330 Article (Published version) Public J.Lemoine.pdf 280020 application/pdf openAccess

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Structural characterization of the exocellular polysaccharides produced by Streptococcus thermophilus SFi39 and SFi12	Applied and environmental microbiology			1997	447	218

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Favre, Nicole