Genome-wide transcriptional responses to sulfite in Saccharomyces cerevisiae.

Sulfite is a commonly used preservative in foods, beverages, and Pharmaceuticals because it is toxic to many microorganisms. In order to understand the global response of Saccharomyces cerevisiae to sulfite, genome-wide transcript profiling following sulfite exposure was obtained. The transcription levels of 21 genes were increased more than 2-fold, while those of 37 genes decreased to a similar extent. Genes involved in carbohydrate metabolism represented the highest proportion of induced genes, which may account for the easily acquired resistance to sulfite. Most of down-regulated genes are involved in transcription, protein biosynthesis, and cell growth. The down-regulation of these genes is thought to reflect growth arrest which occurs during sulfite treatment, allowing cells to save energy. Cells treated with sulfite generated more than 70% of acetaldehyde than untreated cells, suggesting that the increased acetaldehyde production is correlated with the induction of PDC1 gene encoding pyruvate decarboxylase.