Elemental Sulfur Inhibits Yeast Growth via Producing Toxic Sulfide and Causing Disulfide Stress.

Elemental sulfur is a common fungicide, but its inhibition mechanism is unclear. Here, we investigated the effects of elemental sulfur on the single-celled fungus Saccharomyces cerevisiae and showed that the inhibition was due to its function as a strong oxidant. It rapidly entered S. cerevisiae . Inside the cytoplasm, it reacted with glutathione to generate glutathione persulfide that then reacted with another glutathione to produce H 2 S and glutathione disulfide. H 2 S reversibly inhibited the oxygen consumption by the mitochondrial electron transport chain, and the accumulation of glutathione disulfide caused disulfide stress and increased reactive oxygen species in S. cerevisiae . Elemental sulfur inhibited the growth of S. cerevisiae ; however, it did not kill the yeast for up to 2 h exposure. The combined action of elemental sulfur and hosts' immune responses may lead to the demise of fungal pathogens.