Factors Affecting Volatile Phenol Production During Fermentations with Pure and Mixed Cultures of Dekkera bruxellensis and Saccharomyces cerevisiae

Janez Kosel, Neža Čadež and Peter Raspor^1*

University of Ljubljana, Biotechnical Faculty, Jamnikarjeva 101, SI-1000 Ljubljana, Slovenia
¹Current address: University of Primorska, Faculty of Health Sciences, Polje 42, SI-6310 Izola, Slovenia

Article history:
Received July 17, 2013
Accepted February 4, 2014

Key words:
Saccharomyces cerevisiae, Dekkera bruxellensis, wine fermentation, volatile phenols

Summary:
The paper examines the impact of ethanol, and hidroxycinnamic and vinylphenol precursors on the production of volatile phenols in fermentations of mixed and pure cultures of yeasts Saccharomyces cerevisiae and Dekkera bruxellensis. Three different D. bruxellensis strains were examined and they all showed a unique volatile phenol production pattern in the fermentations of pure and mixed cultures. Generally, the results showed that in mixed culture fermentations less vinylphenols and more ethylphenols were produced in comparison with D. bruxellensis pure culture fermentations. Vinylphenol precursors significantly inhibited the growth of S. cerevisiae and the production of ethylphenols. Nevertheless, it was found that D. bruxellensis genes encoding for enzymes coumaric acid decarboxylase (CAD) and vinylphenol reductase (VPR) are more responsive to vinylphenol precursors in  comparison with hidroxycinnamic acids. Consequently, higher concentrations of vinylphenols in the cell were found to be more cytotoxic than hidroxycinnamic acids. In general, low ethanol concentrations induced higher production of volatile phenols by S. cerevisiae and D. bruxellensis. This was confirmed with the expression pattern of gene encoding for CAD of D. bruxellensis.

*Corresponding author:      This email address is being protected from spambots. You need JavaScript enabled to view it.