Spoilage of red wine by the yeast species
Dekkera bruxellensis
is a common problem for the global wine
industry. When conditions are conducive for growth of these yeasts in wine, they ef
fi
ciently convert non-
volatile hydroxycinnamic acids into aroma-active ethylphenols, thereby reducing the quality of the wine.
It has been demonstrated previously that dissolved oxygen is a key factor which stimulates
D. bruxellensis
growth in wine. We demonstrate that whereas the presence of oxygen accelerates the growth of this
species, oxygen-limited conditions favour 4-ethylphenol production. Consequently, we evaluated wine
spoilage potential of three
D. bruxellensis
strains (AWRI1499, AWRI1608 and AWRI1613) under oxygen-
limited conditions. Each strain was cultured in a chemically-de
fi
ned wine medium and the fermentation
products were analysed using HPLC and HS-SPME
e
GC/MS. The strains displayed different growth
characteristics but were equally capable of producing ethylphenols. On the other hand, signi
fi
cant dif-
ferences were observed for 18 of the remaining 33 metabolites analysed and duo-trio sensory analysis
indicated signi
fi
cant aroma differences between wines inoculated with AWRI1499 and AWRI1613. When
these wines were spiked with low concentrations of 4-ethylphenol and 4-ethylguaiacol, no sensorial
differences could be perceived. Together these data suggest that the three predominant
D. bruxellensis
strains previously isolated during a large survey of Australian wineries do not differ substantively in their
capacity to grow in, and spoil, a model wine medium.