Structure and properties of the exopolysaccharide produced by Streptococcus macedonicus Sc136

Abstract

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.

Novel sulfated phosphoglycolipids from Natronomonas moolapensis

“…Furthermore, NOE-coupling of H gal 1-H gal 3 is observed (data not shown). Consistent with Vincent et al (2001), the 1D 1 H TOCSY with selective excitation of the anomeric proton revealed only three proton signals which could be assigned to H gal 2-H gal 4 (Suppl. Fig.…”

Biodiversity of Exopolysaccharides Produced by Streptococcus thermophilus Strains Is Reflected in Their Production and Their Molecular and Functional Characteristics

“…To our knowledge, this has never been found in EPS from S. thermophilus until now. EPS from Lactobacillus helveticus TY1-2 (76), Lactobacillus acidophilus LMG 9433 (50), and Streptococcus macedonicus Sc 136 (73) have been reported to contain the same monomers (galactose, glucose, and N-acetylglucosamine) as the EPS from S. thermophilus ST 30 (this study), albeit in different ratios. The EPS from Lactobacillus rhamnosus GG (30) is composed of N-acetylglucosamine, galactose, and rhamnose.…”

Lactic Acid Bacteria: Genetics, Metabolism and Applications

“…In recent work the available information is transformed into structure-function relationships (Jay et al 1998;Vincent et al 2001;Duboc et al 2002). Beyond these structure-based relationships, molecular modeling is appearing as a growingly important tool for the development of atomic-scale models (Perez et al 1996;Faber et al 2002) presenting a link to macroscopic properties such as rheology and the capacity for interactions with other molecules present in the medium (Figure 1).…”

“…Modification of EPSs into biologically active carbohydrates can be envisaged. Recently, Vincent et al (2001) determined the structure of a polysaccharide produced by Streptococcus macedonicus Sc136 that contains the trisaccharide sequence ,B-D-GlcpNAc-(1-+3)-,8-D-Galp-(1-+4)-,8-D-Glcp. This corresponds to an internal EPS backbone of lacto-N-tetraose and lacto-N-neotetraose.…”