Sucrose metabolism by prominent members of the flora isolated from cariogenic and non-cariogenic dental plaques

Abstract

Sucrose metabolism by resting-cell suspensions of pure cultures of representative members of the predominant cultivable flora isolated from cariogenic and non-cariogenic dental plaque was investigated by means of radiochemical techniques. Streptocococcus mutans utilized sucrose at a considerably faster rate than S. sanguis, S. mitis, Actinomyces viscosus, A. naeslundii, or Lactobacillus casei, forming lactic acid, intracellular polysaccharide, insoluble extracellular glucan, and lactic acid from intracellular polysaccharide catabolism at faster rates than the other bacteria. The Actinomyces formed more volatile acids than the streptococci, mostly acetic, and S. sanguis formed more soluble extracellular polysaccharide than the other bacteria. The metabolic activity of S. mutans resembled the pattern of sucrose metabolism of cariogenic plaque, whereas the metabolic activity of the Actinomyces species, the predominant members of non-cariogenic plaque flora, resembled the sucrose metabolism of non-cariogenic plaques.