Structure and properties of the exopolysaccharide produced by Streptococcus macedonicus Sc136.
Streptococcus macedonicus is a Gram positive lactic acid bacterium that is part of the starter flora present in Greek sheep and goat cheeses. The S. macedonicus Sc136 strain produces a high-molecular-mass, highly texturizing exopolysaccharide composed of D-glucose, D-galactose, and N-acetyl-D-glucosamine in the molar ratio of 3:2:1. The structure of the exopolysaccharide produced by S. macedonicus Sc136 was determined by chemical analysis, mass spectrometry, and nuclear magnetic resonance spectroscopy. The repeating unit was shown to be: (see text) The polysaccharide sidechain beta-D-Galf-(1-->6)-beta-D-Glcp-(1-->6)-beta-D-GlcpNAc is a key factor in the highly texturizing properties of the S.macedonicus Sc136 exopolysaccharide. Finally, the trisaccharide sequence beta-D-GlcpNAc-(1-->3)-beta-D-Galp-(1-->4)-beta-D-Glcp corresponds to the internal backbone of the lacto-N-tetraose and lacto-N-neotetraose units, which serve as a structural basis for the large majority of human milk oligosaccharides, an additional property offering an important potential for the development of improved infant nutrition products.
Vincent
S J
SJ
Nestlé Research Center, Vers-chez-les-Blanc, CH-1000 Lausanne 26, Switzerland.
Faber
E J
EJ
Neeser
J R
JR
Stingele
F
F
Kamerling
J P
JP
D002240:Carbohydrate Sequence; D008401:Gas Chromatography-Mass Spectrometry; D008745:Methylation; D008969:Molecular Sequence Data; D019906:Nuclear Magnetic Resonance, Biomolecular; D011135:Polysaccharides, Bacterial / Q000737:chemistry* / Q000302:isolation & purification / Q000378:metabolism*; D013291:Streptococcus / Q000737:chemistry*
D011135:Polysaccharides, Bacterial; C098632:exopolysaccharide, Streptococcus