Metabolic changes of Issatchenkia orientalis under acetic acid stress by transcriptome profile using RNA-sequencing

Issatchenkia orientalis (I. orientalis) is tolerant to various environmental stresses especially acetic acid stress in wine making. However, limited literature is available on the transcriptome profile of I. orientalis under acetic acid stress. RNA-sequence was used to investigate the metabolic changes due to underlying I. orientalis 166 (Io 166) tolerant to acetic acid. Transcriptomic analyses showed that genes involved in ergosterol biosynthesis are differentially expressed under acetic acid stress. Genes associated with ribosome function were downregulated, while energy metabolism-related genes were upregulated. Moreover, Hsp70/Hsp90 and related molecular chaperones were upregulated to recognize and degrade misfolded proteins. Compared to Saccharomyces cerevisiae, transcriptomic changes of Io 166 showed many similarities under acetic acid stress. There were significant upregulation of genes in ergosterol biosynthesis and for the application of wine production.