Plasma membrane injury induced by nonyl gallate in Saccharomyces cerevisiae.

The aim was to investigate the antifungal actions of nonyl gallate against Saccharomyces cerevisiae ATCC 7754. The maximum potency of both the growth inhibitory and the fungicidal effect against the yeast strain was found in nonyl gallate among n-alkyl gallates tested. Nonyl gallate induced ROS generation dose-dependently in growing cells. This ester rapidly killed yeast cells even when cell division was restricted by cycloheximide. This ester inhibited glucose-induced medium acidification and promoted the efflux of intracellular potassium ions in a nongrowing condition. Moreover, nonyl gallate induced a leakage of calcein from artificially prepared liposomes to a greater extent than dodecyl gallate did. These results suggested nonyl gallate injured plasma membrane of S. cerevisiae, resulting in its exhibition of fungicidal effect accompanying with a leakage of intracellular materials from the cells. Our study reveals new knowledge on the antifungal actions of nonyl gallate against S. cerevisiae. When nonyl gallate is applied as a food preservative, the level of its addition to foods may be reduced because of its potent antifungal activity compared with weak acids including sorbic acid and benzoic acid.