Inhibition of the expression of cell-associated fructosyltransferase in Streptococcus salivarius by octyl beta-D-glucopyranoside.

Octyl beta-D-glucopyranoside prevented the expression of cell-associated fructosyltransferase activity in Streptococcus salivarius ATCC 25975 grown in batch culture or incubated in nonproliferating cell suspension medium. This effect was not due to the direct inhibition of enzyme activity nor due to the loss of active enzyme into the external medium. The prevention of enzyme expression did not appear to be due to the inhibition of a general translocation mechanism for protein secretion, since fructosyltransferase activity was not detected within the cytoplasm of lysed cells grown in the presence of octyl beta-D-glucopyranoside; nor was there any observed inhibition of the secretion of the extracellular enzyme glucosyltransferase. These and other observations supported the view that fructosyltransferase was not secreted across the cytoplasmic membrane in an active form before becoming associated with the cell surface.