[Isolation and characteristics of a protein-polysaccharide complex, secreted by Bifidobacterium adolescentis]

Extracellular fibrillar protein-polysaccharide complex (PPC) of Bifidobacterium adolescentis was found to be bound to the outer surface of the cell wall. However, at the late stages of B. adolescentis cultivation (48-72 h of growth), it also occurred in the culture liquid, which can be explained by the expansion of the outer material of the cell wall. PPCs isolated from the cell surface and culture liquid contained proteins and carbohydrates in a ratio of 1:1 and from 1:4 to 1:5, respectively. PPC exerted a concentration-dependent bifidogenic effect: it stimulated growth, acidogenesis, accumulation of extracellular proteins and enzymes, and sugar utilization in B. adolescentis cells grown in synthetic Eagle's medium. PPC also promoted the rehabilitation of anabiotic forms of B. adolescentis. The PPC variants III-DN-48 and IV-DN-24, isolated from the cell surface of B. adolescentis, had the most pronounced bifidogenic effect.