[The biological properties of Bifidobacterium]

The possibility of the formation of exoenzymes, such as DNAase, RNAase and hemolysin, by bifidobacteria was studied in comparison with their acid-forming and adhesive activity. Bifidobacterium reference strains, originally isolated from healthy adults and children, were studied. The study involved altogether 73 strains of bifidobacteria, including 24 B. bifidum strains, 13 B. adolescentis strains, 7 B. infantis strains, 10 B. breve strains and 19 B. longum strains. The bifidobacteria under study were shown to differ not only in the presence and activity of properties useful for macroorganisms, but also in the presence of enzymes having depolymerizing activity (DNAase, hemolysin). Thus, out of 73 strains under study 9 proved to be DNAase-positive and 6, hemolysin positive. At the same time a specific feature of bifidobacteria was their high acid-forming activity with the complete absence of RNAase activity and insignificant DNAase- and hemolysin-forming activity.