Transcription profiling of sparkling wine second fermentation

Area of Science:

• Enology
• Microbiology
• Yeast Genetics

Background:

• Sparkling wine production via the traditional method involves a second fermentation.
• Yeast cells face unique stress factors during this stage, including high ethanol, low pH, nitrogen starvation, low temperature, and CO2 overpressure.
• While yeast transcription during primary fermentation is well-studied, the response during secondary fermentation remains largely unexplored.

Purpose of the Study:

• To investigate the transcriptional profile of Saccharomyces cerevisiae under the specific stress conditions of sparkling wine's second fermentation.
• To identify the key cellular pathways and genes affected during this critical winemaking phase.

Main Methods:

• Analysis of the yeast transcriptome (gene expression profile) of Saccharomyces cerevisiae.
• Comparison of gene expression patterns under second fermentation conditions versus primary fermentation.

Main Results:

• The study identified affected pathways primarily related to aerobic respiration, vacuolar, and peroxisomal functions.
• A strong correlation was observed between yeast transcription profiles during primary and second fermentations.
• Ethanol concentration emerged as the primary driver of gene transcription, with low temperature also showing a notable influence.

Conclusions:

• The findings provide the first comprehensive look at yeast gene expression during sparkling wine secondary fermentation.
• Ethanol and low temperature are key environmental factors modulating yeast's genetic response in this process.
• Understanding these responses can aid in optimizing sparkling wine quality and production efficiency.