Physiological profiles relevant for novel alcoholic beverage design amongDekkera bruxellensisstrains from different provenances

Abstract

A selection of D. bruxellensis strains from different geographical and beverage sources were tested for their potential to develop novel alcoholic beverages. Selected strains were initially clustered based on genetic similarities determined by PCR fingerprinting. Physiological profiles were subsequently determined during the fermentation experiments that were carried out in a defined synthetic medium supplemented with glucose and 4-vinylphenol for 22 days, as static cultures under microaerobic conditions. There were significant differences (p ≤ 0.05) in ethanol, glycerol and acetic acid yields and in the growth rates between the strains. During prolonged fermentation, a reduction in ethanol and acetic acid was observed, ranging from 43 to 54% for ethanol and from 4 to 45% for acetic acid, which was strain or genetic group specific. Consumption of ethanol and acetic acid occurred during the stationary phase, suggesting that ethanol and acetic acid were utilized for processes other than growth and must have had an impact on the formation of the aromatic profile. The conversion of 4-vinylphenol to 4-ethylphenol was much more efficient and was completed within 4 days of fermentation. Although further investigation is needed, the results indicate a potential of this previously undesired microorganism to be useful for a wide range of applications. Copyright © 2016 The Institute of Brewing & Distilling