On the mechanism of xylitol-dependent inhibition of glycolysis in Streptococcus sobrinus OMZ 176.
1. The mechanism of xylitol-dependent inhibition of glycolysis in Streptococcus sobrinus OMZ 176 was investigated in aerobically and anaerobically grown cells. 2. Glucose-stimulated glycolysis was followed polarographically, by radio-HPLC-analyses of glycolytic intermediates, by measurement of ATP generated, and spectrophotometric monitoring of extent of NAD(P)+/NADPH-status. 3. Xylitol added to suspensions of S. sobrinus inhibited O2 uptake by approximately 20%, and led to a corresponding decrease in rate of lactate formation in aerobic and anaerobic cells. 4. Xylitol also delayed the onset of the glucose-dependent rapid reduction of NAD(P)+ by approximately 1 min, although the total extent of reduction was not significantly affected compared to control cells. 5. The inhibitory effect of xylitol on glucose dependent ATP synthesis, however, was decreased by 70-80%. 6. Hence the dramatic decrease in glucose-dependent synthesis of ATP may be the direct cause of decreased bacterial growth in the presence of xylitol. 7. A mechanism explaining the observed phenomena is proposed.
Forbord
B
B
Department of Physiology and Biochemistry, Dental Faculty, University of Oslo, Norway.
Osmundsen
H
H
D000255:Adenosine Triphosphate / Q000096:biosynthesis; D000332:Aerobiosis; D000693:Anaerobiosis; D002851:Chromatography, High Pressure Liquid; D005947:Glucose / Q000494:pharmacology; D006019:Glycolysis / Q000187:drug effects*; D009249:NADP / Q000378:metabolism; D010084:Oxidation-Reduction; D010101:Oxygen Consumption / Q000187:drug effects; D013053:Spectrophotometry; D016986:Streptococcus sobrinus / Q000187:drug effects / Q000378:metabolism*; D014993:Xylitol / Q000494:pharmacology*
D009249:NADP; D000255:Adenosine Triphosphate; D005947:Glucose; D014993:Xylitol