AMOUNT DISTRIBUTION AND METABOLISM OF SOLUBLE POLYSACCHARIDES IN HUMAN DENTAL PLAQUE

Twenty-four-hr. accumulations of human dental plaque were extracted with distilled water and cold 0. 5 [image] sodium hydroxide for soluble hexose components. Seventy-six plaques had a mean soluble polysaccharide content of 9. 0 (S. D. 3. 52) percent dry weight of plaque. The major component sugars of this material were glucose and fructose, and only small amounts of typical bacterial cell wall sugars were present Plaque which was dried and stored before extraction gave higher values for soluble polysaccharide 10. 7 (S. D. 2. 46) percent dry weight of plaque than fresh plaque collected into water 7. 3 (S. D. 3. 95). When plaque was incubated at 37[degree]C for 2 hr. the water-soluble polysaccharide generally decreased indicating that it was metabolized. The sodium hydroxide soluble polysaccharide often increased. It is concluded that this polysaccharide is a major part of the plaque matrix, that it is present as the extracellular polysaccharide dextran and levan, and that some part of the water-soluble fraction of this material can be metabolized by the plaque.