Abstract
The bacteriocinogenic and highly adhesive strains were screened in laboratory stock strains of Streptececcus mutans for isolation of low -cariogenicity mutants which could act against wild strains of S. mutans All tested strains of S. mutans inhibited the growth of Streptececcus mutans and Streptececcus faecalis. In particular, S. mutans P2, C67-1, B14, and OMZ 175 showed bacteriocin activity against many tested strains of S. mutans. Of these four strains, S. mutans B14 could adhere to the smooth surface of glass and establish itself in the oral cavity of hamsters to the same degree as a highly cariogenic strain S. mutans K1-R.
S. mutans B14 produced bacteriocin on Todd-Hewitt and trypticase soy-yeast extract agar plate, but not on brain heart infusion or trypticase soy agar plate. In broth culture, stabilizing agents like agar, yeast extract, and starch had only a slight effect on the production of bacteriocin.
The bacteriocin produced by S. mutans B14 was heatstable and sensitive to protease, but insensitive to DNase, RNase, and catalase. The molecular weight of the bacteriocin was estimated at 1, 000-3, 500 by dialysis. It was assumed that molecules of bacteriocin aggregated with each other or with the materials of the culture medium because of the dialysis and gel filtration.
