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Modulation of Glycerol and Ethanol Yields During Alcoholic Fermentation in Saccharomyces cerevisiae Strains Overexpressed or Disrupted for GPD1 Encoding Glycerol 3‐Phosphate Dehydrogenase
Author(s) -
Michnick Sumio,
Roustan JeanLouis,
Remize Fabienne,
Barre Pierre,
Dequin Sylvie
Publication year - 1997
Publication title -
yeast
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.923
H-Index - 102
eISSN - 1097-0061
pISSN - 0749-503X
DOI - 10.1002/(sici)1097-0061(199707)13:9<783::aid-yea128>3.0.co;2-w
Subject(s) - glycerol 3 phosphate dehydrogenase , glycerol , biochemistry , fermentation , acetoin , acetaldehyde , alcohol dehydrogenase , pyruvate decarboxylase , dehydrogenase , ethanol fermentation , biology , ethanol , yeast , saccharomyces cerevisiae , enzyme
The possibility of the diversion of carbon flux from ethanol towards glycerol in Saccharomyces cerevisiae during alcoholic fermentation was investigated. Variations in the glycerol 3‐phosphate dehydrogenase (GPDH) level and similar trends for alcohol dehydrogenase (ADH), pyruvate decarboxylase and glycerol‐3‐phosphatase were found when low and high glycerol‐forming wine yeast strains were compared. GPDH is thus a limiting enzyme for glycerol production. Wine yeast strains with modulated GPD1 (encoding one of the two GPDH isoenzymes) expression were constructed and characterized during fermentation on glucose‐rich medium. Engineered strains fermented glucose with a strongly modified [glycerol] : [ethanol] ratio. gpd1 Δ mutants exhibited a 50% decrease in glycerol production and increased ethanol yield. Overexpression of GPD1 on synthetic must (200 g/l glucose) resulted in a substantial increase in glycerol production (×4) at the expense of ethanol. Acetaldehyde accumulated through the competitive regeneration of NADH via GPDH. Accumulation of by‐products such as pyruvate, acetate, acetoin, 2,3 butane‐diol and succinate was observed, with a marked increase in acetoin production. © 1997 John Wiley & Sons, Ltd.