EFFECTS OF CERTAIN SALTS ON GLUCOSYLTRANSFERASE SYNTHESIS BY STREPTOCOCCUS-MUTANS STRAIN PS-14

We investigated the effects of various salts on the synthesis of extracellular glucosyltransferase in a partially defined medium (M4) by Streptococcus mutans strain PS-14 and by certain other selected strains. The levels of glucosyltransferase produced by S. mutans strain PS-14 were found to increase to a maximum of seven-fold with increasing (NH4)2SO4 concentrations. However, at a 2% concentration of the salt, the level was stimulated 2.5-fold, and the growth was inhibited by 75%. A 1% concentration of MgSO4 or NaCl also caused an increase of glucosyltransferase of six-fold or 2.4-fold, respectively. However, for S. mutans strain B-13N, the enzyme production was not stimulated by (NH4)SO4, MgSO4, or NaCl. Moreover, the enzyme production by serotypes c, e, and f was found to be stimulated by 1% (NH4)2SO4, whereas the enzyme production by serotypes d and g was not affected.