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Comparison of the thickening properties of four Lactobacillus delbrueckii subsp. bulgaricus strains and physicochemical characterization of their exopolysaccharides

2003; Oxford University Press; Volume: 221; Issue: 2 Linguagem: Inglês

10.1016/s0378-1097(03)00214-3

1574-6968

Sandrine Pétry, Sylviane Furlan, W. Earle Waghorne, Luc Saulnier, Jutta Cerningâ€, Emmanuelle Maguin,

Polysaccharides Composition and Applications

It is now well established that physicochemical properties of exopolysaccharides (EPS) can vary between strains of a given species and according to growth conditions. The EPS production of four strains of Lactobacillus bulgaricus was monitored during growth in milk and in a chemically defined media. All strains, including the non-ropy one, produced EPS. The monosaccharide composition, molar mass (M(w)), and intrinsic viscosity of these EPS were determined and compared. Further characterization using high-performance size-exclusion chromatography revealed the presence of two fractions in all EPS: one fraction exhibited a high M(w) and a high intrinsic viscosity while the other had a low M(w) and a low intrinsic viscosity. Strikingly, the EPS synthesized by the non-ropy strain was mainly composed of the low-M(w) fraction while for the ropy strains, the fraction of high M(w) varied between 43 and 90%. According to our results, we propose that the ratio between the high-M(w) and low-M(w) fractions is critical for the texturing properties of L. bulgaricus EPS.