Elucidation of ethanol tolerance mechanisms in Saccharomyces cerevisiae by global metabolite profiling.
Ethanol, the major fermentation product of yeast, is a stress factor in yeast. We previously constructed an ethanol-tolerant mutant yeast iETS3 by using the global transcriptional machinery engineering. However, the ethanol-tolerance mechanism has not been systematically investigated. In this study, global metabolite profiling was carried out, mainly by gas chromatography/time-of-flight mass spectrometry (GC/TOF MS), to investigate the mechanisms of ethanol tolerance in iETS3. A total of 108 intracellular metabolites were identified by GC/TOF MS and high performance liquid chromatography, and these metabolites were mostly intermediates of the central carbon metabolism. The metabolite profiles of iETS3 and BY4741, cultured with or without ethanol, were significantly different based on principal component and hierarchical clustering analyses. Our metabolomic analyses identified the compositional changes in cell membranes and the activation of glutamate metabolism and the trehalose synthetic pathway as the possible mechanisms for the ethanol tolerance. These metabolic traits can be considered possible targets for further improvement of ethanol tolerance in the mutant. For example, the KGD1 deletion mutant, with up-regulated glutamate metabolism, showed increased tolerance to ethanol. This study has demonstrated that metabolomics can be a useful tool for strain improvement and phenotypic analysis of microorganisms under stress.
Department of Biotechnology, Graduate School, Korea University, Seoul, Republic of Korea.
Sooah
S
Kim
Department of Biotechnology, Graduate School, Korea University, Seoul, Republic of Korea.
Jungyeon
J
Kim
Department of Biotechnology, Graduate School, Korea University, Seoul, Republic of Korea.
Ju Hwan
JH
Song
Department of Biotechnology, Graduate School, Korea University, Seoul, Republic of Korea.
Young Hoon
YH
Jung
Department of Biotechnology, Graduate School, Korea University, Seoul, Republic of Korea.
Il-Sup
IS
Choi
Department of Life Sciences, Ewha Womans University, Seoul, Republic of Korea.
Wonja
W
Choi
Department of Bio and Fermentation Convergence Technology, Kookmin University, Seoul, Republic of Korea.
Yong-Cheol
YC
Park
Department of Agricultural Biotechnology and Center for Food and Bioconvergence, Seoul National University, Seoul, Republic of Korea.
Jin-Ho
JH
Seo
Department of Biotechnology, Graduate School, Korea University, Seoul, Republic of Korea. khekim@korea.ac.kr.
Kyoung Heon
KH
Kim
D016000:Cluster Analysis; D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D055432:Metabolomics / Q000379:methods*; D025341:Principal Component Analysis; D012441:Saccharomyces cerevisiae / Q000254:growth & development* / Q000378:metabolism; D029701:Saccharomyces cerevisiae Proteins / Q000378:metabolism*; D013312:Stress, Physiological
D029701:Saccharomyces cerevisiae Proteins; D000431:Ethanol
Ethanol tolerance; Metabolite profiling; Metabolomics; Saccharomyces cerevisiae