The exopolysaccharides produced by Streptococcus thermophilus Rs and Sts have the same repeating unit but differ in viscosity of their milk cultures

Structure of the exopolysaccharide produced by Streptococcus thermophilus S3

“…cremoris, 13,14 and Streptococcus thermophilus. [15][16][17][18] S. thermophilus strains in combination with Lb. delbrueckii subsp.…”

Structure of the extracellular polysaccharide produced by Lactobacillus delbrueckii subsp. bulgaricus 291

“…Both GLC and GLC -MS analyses were performed using conditions as described previously. 23 Matrixassisted laser desorption ionization time-offlight mass spectrometry (MALDI-TOF -MS) experiments were performed using a Voyager-DE mass spectrometer equipped with a nitrogen laser. Samples were prepared by mixing directly on the target 1 mL oligosaccharide alditol solution with 2 mL aq 10% 2,5-dihydroxybenzoic acid as matrix solution.…”

“…27,28 For methylation analysis, the polysaccharide and isolated oligosaccharide alditols were subsequently permethylated, hydrolyzed, reduced, and acetylated, as described previously. 23 The obtained partially methylated alditol acetates were identified by GLC and by GLC -MS. 26,29 Partial acid hydrolysis. -The exopolysaccharide (15 mg) was treated with 0.3 M trifluoroacetic acid (15 mL) for 1 h at 100°C.…”

Binding Interactions Between α-glucans from Lactobacillus reuteri and Milk Proteins Characterised by Surface Plasmon Resonance

“…35 Thus, EPS-milk protein interactions, but also the intrinsic viscosity of the EPS itself, 36 are important for the texture. Intrinsic viscosity increases with increasing EPS molecular weight 34 and chain stiffness 36,37 . High molecular weight EPS may thus increase the viscosity by interacting with κ-casein and by contributing with its high intrinsic viscosity, while EPS with rigid chains may not interact with milk proteins and only contribute to texture solely by increasing the viscosity of the serum phase.…”

“…The molecular mass may not directly affect the HoPS chain flexibility, but analysis of heteropolysaccharides of Streptococcus thermophilus showed that increased molecular weight of EPS resulted in increased viscosity, although the protein-EPS network did not seem to be affected. 34 The gluc55730 and glucML1 of the lowest molecular mass give most efficient binding to native β-lactoglobulin and glucan size may influence the higher level of κ-casein binding in addition to a high content of α-(1,6) linkages. In case of glucan binding to native β-lactoglobulin, the suppression by a high degree of α-(1,6) linkages may be more important than the size of the glucan for the binding level.…”