Glucose repression of FLO11 gene expression regulates pellicle formation by a wild pellicle-forming yeast strain isolated from contaminated wine

ABSTRACT

Some wild strains of Saccharomyces cerevisiae form a pellicle on the surface of contaminated wines during the post-fermentation period of wine making. In this study, we found that both pellicle formation and FLO11 expression by a wild pellicle-forming strain of S. cerevisiae isolated from contaminated wine were repressed in a glucose-containing medium. Substitution of the promoter region of FLO11 in the cells with a constitutive promoter caused derepression of pellicle formation in the glucose-containing medium and wine. These findings indicate that glucose repression of the expression of the FLO11 gene, but not the glucose repression of the expression of other glucose-repressed genes, is responsible for the glucose-dependent regulation of pellicle formation by the wild pellicle-forming yeast strain. Furthermore, we found that the wild pellicle-forming strain had the same deletion of the 111-bp repression sequence in the FLO11 promoter as the flor strains commercially used for making sherry-like wines. Based on the results obtained in this study, a new method that would prevent deleterious pellicle formation in wineries is discussed.

KEYWORDS:

• Pellicle formation
• wild yeast
• Saccharomyces cerevisiae
• contaminated wine
• FLO11 expression
• glucose repression

Acknowledgments

We thank Mr Shuhei Mochiduki of our laboratory for his technical support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was partially supported by JSPS KAKENHI [grant number 24780069].