Membrane perturbation by cerulenin modulates glucosyltransferase secretion and acetate uptake by Streptococcus salivarius

Abstract

Cerulenin and dodecanoic acid prevented the synthesis and secretion of glucosyltransferase in non-proliferating cell suspensions of Streptococcus salivarius ATCC 25975 under conditions that also inhibited the incorporation of radioactively labelled acetate into the cell. In the presence of Tween 80, acetate incorporation was not markedly affected by cerulenin despite the fact that glucosyltransferase secretion was still inhibited. Cerulenin and dodecanoic acid were found to prevent the incorporation of radioactively labelled acetate by affecting the uptake of acetate by the cell. In the case of cerulenin, the inhibition of uptake of acetate by the cell was partially relieved by the addition of Tween 80. These and other observations strongly suggested that cerulenin inhibited glucosyltransferase secretion and acetate incorporation by perturbing the membrane, rather than by directly inhibiting lipid synthesis.