Plasma membrane injury induced by nonyl gallate in Saccharomyces cerevisiae

Aims: The aim was to investigate the antifungal actions of nonyl gallate against Saccharomyces cerevisiae ATCC 7754. Methods and Results: 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. Conclusions: 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. Significance and Impact of the Study: 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.