Uptake and expulsion of 14C-xylitol by xylitol-cultured Streptococcus mutans ATCC 25175 in vitro.
The effect of successive cultivations in the presence of 6% xylitol on the uptake and expulsion of 14C-xylitol was studied using the cells of Streptococcus mutans 25175. Three sequential cultivations did not alter the growth inhibition percentage (approximately 50%) observed in the presence of 6% xylitol. The 14C-xylitol uptake experiments performed with growing and resting cells showed that both the uptake and the expulsion of xylitol were enhanced by xylitol-culturing. Both xylitol-cultured and resting control cells contained only one major labeled compound which was identified as 14C-xylitol 5-phosphate. The label subsequently was expelled from the cells as 14C-xylitol. These results indicate that S. mutans possesses an intracellular xylitol cycle and this cycle is regulated by adding xylitol to the growth medium.
Söderling
E
E
Department of Biochemistry, University of Turku, Finland.
Pihlanto-Leppälä
A
A
D002250:Carbon Radioisotopes / Q000378:metabolism; D002455:Cell Division / Q000187:drug effects; D002855:Chromatography, Thin Layer; D003470:Culture Media; D004352:Drug Resistance, Microbial; D013295:Streptococcus mutans / Q000187:drug effects / Q000378:metabolism*; D014993:Xylitol / Q000378:metabolism* / Q000494:pharmacology
D002250:Carbon Radioisotopes; D003470:Culture Media; D014993:Xylitol