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Potassium and sodium content and acid production of nongrowing cariogenic streptococci
Author(s) -
LUOMA HEIKKI
Publication year - 1971
Publication title -
european journal of oral sciences
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.802
H-Index - 93
eISSN - 1600-0722
pISSN - 0909-8836
DOI - 10.1111/j.1600-0722.1971.tb02010.x
Subject(s) - potassium , chemistry , sodium , ammonium , fermentation , extracellular , biochemistry , food science , organic chemistry
– Washed cells of K‐l streptococcus, cariogenic to rat, were incubated in buffer solutions free of growth‐promoting agents. In the presence of external potassium at pH 5.8, only a high concentration of ammonium could reduce the fermentative accumulation of potassium by the cells. In the absence of extracellular potassium, a high concentration of external sodium or ammonium extruded the “original” potassium of the fermenting cells. Acid production by the organisms, as indicated by the decrease in the suspension pH, increased markedly with the increase in external potassium. The ammonium ion interfered with the cellular potassium transfer more than did sodium, but acid production was lower in the presence of the latter. The fermentative decrease in the suspension pH from 7.2 to 4.7 in the presence of potassium was slightly inhibited by a large addition of external sodium. Concomitantly the cellular sodium was increased threefold.