Abstract
An enzyme which possesses lytic activity against cariogenic streptococci was obtained from strains of streptomyces in soil and sewage. The strains of streptomyces which produced a highly active enzyme in the culture supernatant were identified as Streptomyces griseus strain H-402 and Streptomyces gloaisporus strain 1829. The enzyme of S. globisporus strongly lysed the strains of cariogenic streptococci in the tris acid malate-NaOH buffer, pH 7.0.
This study is concerned with the estimation of the bacteriolytic activity of the enzyme derived from S. globisporus on cariogenic microorganisms such as the strains of Streptococcus mutans, Lactobacillus casei and Actinomyces viscosus, and also deals with the effect of fluoride ion, sodium N-lauroylsarcosinate and sodium dehydroacetate on the activity of the bacteriolytic enzyme.
Twenty seven strains of S. mutans employed in this experiment were all sensitive to the bacteriolytic enzyme. Dergrees of bacteriolysis were compared with each of 5 serological groups of S. mutans. Strains of group a and b were more sensititive to the enzyme than group, c, d and E. Cariogenic L. casei ATCC 4646 and A. viscosus T6 were also extremely sensitive, whereas 4 strains of Streptococcus sanguis were less sensitive to the enzyme.
Strains of S. mutans and S. sanguis which showed the least sensitivity to the enzyme were significantly lysed by prolonged incubation with the enzyme.
The bacteriolytic activity was apparently enhanced by the presence of 20 μg/ml of lysozyme or 0.3% of sodium N-lauroylsarcosinate. 0.2% of sodium dehydroacetate was also effective in enhanceing of the enzyme activity. The enzyme activity was not influenced by fluoride ions with a concentration of less than 200 ppm, whereas 40% of the enzyme activity was supressed in the presence of fluoride ions with a concentration of more than 400 ppm. The enzyme activity was also supressed by halide ions such as F-, Cl-, Br-, and I-.
