title: Transcriptome analysis of acetic-acid-treated yeast cells identifies a large set of genes whose overexpression or deletion enhances acetic acid tolerance.
abstract: Acetic acid inhibits the metabolic activities of Saccharomyces cerevisiae. Therefore, a better understanding of how S. cerevisiae cells acquire the tolerance to acetic acid is of importance to develop robust yeast strains to be used in industry. To do this, we examined the transcriptional changes that occur at 12 h post-exposure to acetic acid, revealing that 56 and 58 genes were upregulated and downregulated, respectively. Functional categorization of them revealed that 22 protein synthesis genes and 14 stress response genes constituted the largest portion of the upregulated and downregulated genes, respectively. To evaluate the association of the regulated genes with acetic acid tolerance, 3 upregulated genes (DBP2, ASC1, and GND1) were selected among 34 non-protein synthesis genes, and 54 viable mutants individually deleted for the downregulated genes were retrieved from the non-essential haploid deletion library. Strains overexpressing ASC1 and GND1 displayed enhanced tolerance to acetic acid, whereas a strain overexpressing DBP2 was sensitive. Fifty of 54 deletion mutants displayed enhanced acetic acid tolerance. Three chosen deletion mutants (hsps82Δ, ato2Δ, and ssa3Δ) were also tolerant to benzoic acid but not propionic and sorbic acids. Moreover, all those five (two overexpressing and three deleted) strains were more efficient in proton efflux and lower in membrane permeability and internal hydrogen peroxide content than controls. Individually or in combination, those physiological changes are likely to contribute at least in part to enhanced acetic acid tolerance. Overall, information of our transcriptional profile was very useful to identify molecular factors associated with acetic acid tolerance.
authors.affiliation: Division of Life and Pharmaceutical Sciences, Ewha Womans University, Seoul, 120-750, Republic of Korea.
authors.forename: Yeji
authors.initials: Y
authors.lastname: Lee
authors.forename: Olviyani
authors.initials: O
authors.lastname: Nasution
authors.forename: Eunyong
authors.initials: E
authors.lastname: Choi
authors.forename: In-Geol
authors.initials: IG
authors.lastname: Choi
authors.forename: Wankee
authors.initials: W
authors.lastname: Kim
authors.forename: Wonja
authors.initials: W
authors.lastname: Choi
mesh_terms: D019342:Acetic Acid / Q000633:toxicity*; D004361:Drug Tolerance; D015870:Gene Expression; D020869:Gene Expression Profiling; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000235:genetics*; D017384:Sequence Deletion
chemical_list: D019342:Acetic Acid