Enhancement of the initial rate of ethanol fermentation due to dysfunction of yeast stress response components Msn2p and/or Msn4p.
Sake yeasts (strains of Saccharomyces cerevisiae) produce high concentrations of ethanol in sake fermentation. To investigate the molecular mechanisms underlying this brewing property, we compared gene expression of sake and laboratory yeasts in sake mash. DNA microarray and reporter gene analyses revealed defects of sake yeasts in environmental stress responses mediated by transcription factors Msn2p and/or Msn4p (Msn2/4p) and stress response elements (STRE). Furthermore, we found that dysfunction of MSN2 and/or MSN4 contributes to the higher initial rate of ethanol fermentation in both sake and laboratory yeasts. These results provide novel insights into yeast stress responses as major impediments of effective ethanol fermentation.
National Research Institute of Brewing, 3-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-0046, Japan.
Daisuke
D
Watanabe
Hong
H
Wu
Chiemi
C
Noguchi
Yan
Y
Zhou
Takeshi
T
Akao
Hitoshi
H
Shimoi
D000434:Alcoholic Beverages / Q000382:microbiology*; D004268:DNA-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D000431:Ethanol / Q000378:metabolism*; D005285:Fermentation; D015966:Gene Expression Regulation, Fungal; D018869:Heat-Shock Response; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012441:Saccharomyces cerevisiae / Q000235:genetics / Q000378:metabolism* / Q000502:physiology; D029701:Saccharomyces cerevisiae Proteins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*
D004268:DNA-Binding Proteins; C081935:MSN2 protein, S cerevisiae; C081937:MSN4 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D014157:Transcription Factors; D000431:Ethanol