pH Change in Artificial Dental Plaque Formed by Glucosyltransferase and Some Oral Bacteria During Batch and Continuous Culture

Abstract

Streptococcus mutans alone or cell-free glucosyltransferase (G-Tase)-together with either Streptococcus sanguis, Streptococcus salivarius, Actinomyces viscosus, or Lactobacillus casei cells-formed artificial dental plaque that firmly adhered to glass electrodes in a continuous culture system containing sucrose. The pH in these artificial plaque samples decreased more than did that of the surrounding medium. In the absence of GTase, the bacteria other than S. mutans did not form firmly-adhering plaque on glass electrodes. The pH of the plaque formed with GTase alone did not show the pH decrease seen when the plaque contained bacteria, but, because it catalyzed the synthesis of glucan, it is suggested that the glucan acts as a diffusion barrier to retard acid loss from plaque containing acid-producing bacteria.

Sensitivity of the Periodontal Pathogen Aggregatibacter actinomycetemcomitans at Mildly Acidic pH

“…The role of secreted acids in dental caries has been well studied 21,27 . However, the role of acids in periodontitis is not clear.…”

Kinetic Properties of Glucosyltransferase Adsorbed Onto Saliva-Coated Hydroxyapatite

“…These extracellular enzymes, synthesizing polysaccharides from sucrose, are associated with the formation of acquired pellicle and d e n t a l plaque [1,2]. For example; glucans were shown to act as a barrier, retarding loss of acid from in vitro formed plaque [12]. For example; glucans were shown to act as a barrier, retarding loss of acid from in vitro formed plaque [12].…”

Insolubilization of exogenous primer dextran with 1,3-α-d-glucan synthase fromStreptococcus mutans

“…formation of dental plaque [1]. Furthermore, the IG acts as a diffusion barrier for acids in dental plaque, inducing tooth decalcification by acids [2]. It has been suggested by several authors that various strains of S. mutans secrete at least 2 glucosyltransferases synthesizing different products [3][4][5][6][7][8].…”