Genetically Improved Yeast Strains with Lower Ethanol Yield for the Wine Industry Generated Through a Two-Round...

Area of Science:

• Enology
• Microbiology
• Yeast Genetics

Background:

• Rising alcohol content in wine, driven by climate change, poses challenges for the wine industry.
• Current methods to reduce wine alcohol are often ineffective, costly, or impact wine quality.
• Microbiological solutions, specifically through yeast strain improvement, are being explored.

Purpose of the Study:

• To develop improved Saccharomyces cerevisiae strains with reduced ethanol yield through a breeding program.
• To address the issue of high alcohol levels in wine caused by climate change.

Main Methods:

• A two-round breeding program was implemented to select for yeast strains with lower ethanol production.
• The heritability of the ethanol yield trait was assessed.
• Selected strains were used for pilot-scale wine production from natural grape must.

Main Results:

• The ethanol yield trait exhibited high heritability (0.619).
• A significant reduction in ethanol yield (10.7%) was achieved within one generation.
• Selected strains, particularly "C2-1B4" and "C7-1B7", produced wine with 0.3–1.5% ABV less than anticipated.

Conclusions:

• Selective breeding is an effective strategy for developing Saccharomyces cerevisiae strains with reduced ethanol yield.
• Improved yeast strains offer a promising microbiological solution for mitigating high alcohol levels in wine.
• Further research is needed to elucidate the relationship between sugar concentration, ethanol yield, and the underlying genetic factors.