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Engineering pathways for malate degradation in Saccharomyces cerevisiae
H Volschenk1, M Viljoen, J Grobler
1Department of Microbiology, University of Stellenbosch, South Africa.
Nature Biotechnology
|March 1, 1997
Summary
This study engineered Saccharomyces cerevisiae for efficient malic acid degradation, crucial for wine production. Introducing genes from other yeasts enabled malate breakdown, improving wine balance, especially in cooler climates.
Area of Science:
- Enology
- Yeast Biotechnology
- Metabolic Engineering
Background:
- Deacidification of grape musts is essential for balanced wine production, particularly in cooler climates.
- Major wine acids include tartaric and malic acid.
- Saccharomyces cerevisiae exhibits inefficient malic acid degradation due to limitations in malate transport and malic enzyme activity.
Purpose of the Study:
- To engineer Saccharomyces cerevisiae for efficient malic acid degradation.
- To introduce functional malate degradation pathways into S. cerevisiae.
Main Methods:
- Cloning and expression of Schizosaccharomyces pombe malate permease (mae1) gene in S. cerevisiae.
- Co-expression of S. pombe malic enzyme (mae2) or Lactococcus lactis malolactic (mleS) gene with mae1.
- Testing degradation efficiency in glycerol-ethanol medium and synthetic grape must.
Main Results:
- Recombinant S. cerevisiae expressing mae1 and mae2 genes degraded 8 g/L of malate aerobically within 7 days.
- Recombinant S. cerevisiae expressing mae1 and mleS genes fermented 4.5 g/L of malate in synthetic grape must within 4 days.
Conclusions:
- Engineered S. cerevisiae strains demonstrate efficient malic acid degradation capabilities.
- This metabolic engineering approach offers a viable strategy for wine deacidification and balance improvement.