Journal of Dental Research, Vol 69, 1244-1247, Copyright © 1990 by International & American Associations for Dental Research Online Journals
Biochemical mechanisms of enhanced inhibition of fluoride on the anaerobic sugar metabolism by Streptococcus sanguis
S. Hata, Y. Iwami, K. Kamiyama and T. Yamada
Department of Oral Biochemistry, Tohoku University School of Dentistry, Sendai, Japan.
The effect of fluoride on acid production by Streptococcus sanguis ATCC
10556 was compared under anaerobic and aerobic conditions. The rate of acid
production under constant-pH and pH-free-fall conditions was determined
during glucose metabolism by resting cells. Anaerobic glycolysis was
inhibited more strongly by fluoride than was aerobic glycolysis.
Intracellular levels of 3-phosphoglyceric, 2-phosphoglyceric, and
phosphoenolpyruvic acids were lower under anaerobic conditions than under
aerobic conditions. Thus, S. sanguis had a low phosphoenolpyruvate (PEP)
potential under anaerobic conditions. This low PEP potential was suggested
to account for the more effective fluoride inhibition of enolase and,
consequently, the reduced transport of sugar by the PEP-dependent
phosphotransferase system of this micro-organism.
