Bacteria of the genus Bifidobacterium are widely used as the basis for probiotic preparations and fermented dietary food products for treatment and prevention of dysbiosis of the digestive tract, stimulation of immune system, and normalization of metabolism. Bacterial surface components, including polysaccharides, are important for the biological activities of bifidobacteria. In this work, we studied glycopolymers of a new strain of Bifidobacterium longum, BIM B‑476, which is resistant to various new generation antibiotics, is stable during storage, and produces biologically active polar lipids.
Stepwise extraction of bacterial cell walls with 10% CCl3CO2H at 4 °C for 24 h and 100 °C for 5 min afforded glycopolymers with oligosaccharyl phosphate repeats of two types (cold extract) and ribitol and glycerol teichoic acids (hot extract). Structures of the glycopolymers were established by monosaccharide analysis, selective cleavage with dilute acetic acid, dephosphorylation with 48% HF, one- and two-dimensional NMR spectroscopy, and high-resolution ESI MS. The ribitol teichoic acid also contains d‑alanine, which presumably terminates the main chain.
