Apparent Synergism between the Interaction of Saccharin, Acesulf ame K, and Fluoride with Hexitol Metabolism by Streptococcus mutans

Abstract

Acesulfame, a structural analogue of saccharin, like the parent compound, markedly decreased the sorbitol- and mannitol-dependent growth rate and growth yield of <i>Streptococcus mutans </i>NCTC 10449 and also decreased the amount of acid produced from these hexitols by the organism. One mechanism by which acesulfame may exert these effects is by competitively inhibiting the interaction of NAD(H) or NADP(H) with a number of pyridine nucleotide-dependent oxidoreductases found in hexitol-adapted cells. Sodium fluoride appeared to act synergistically with both saccharin and acesulfame in serving to decrease both the hexitol-dependent growth rate and growth yield of the organism and also the total amounts of organic acids produced from sorbitol and mannitol. The synergistic negative effects exerted upon hexitol metabolism by saccharin, acesulfame, and fluoride may be due to their collective role in decreasing intracellular levels of phosphoenolpyruvate (PEP), thus interfering with the PEP-dependent transport of sorbitol and mannitol into the cell.