Influences the Expression of Genes Involved in PDH Bypass and Glyceropyruvic Fermentation in .

Previous studies reported that the use of in sequential culture fermentation with mainly induced a reduction of volatile acidity in wine. The impact of the presence of this yeast on the metabolic pathway involved in pyruvate dehydrogenase (PDH) bypass and glycerol production in has never been investigated. In this work, we compared acetic acid and glycerol production kinetics between pure culture and its sequential culture with during alcoholic fermentation. In parallel, the expression levels of the principal genes involved in PDH bypass and glyceropyruvic fermentation in were investigated. A sequential culture of / at an inoculation ratio of 10:1 produced 40% less acetic acid than pure culture and led to the enhancement of glycerol content (12% higher). High expression levels of pyruvate decarboxylase and , acetaldehyde dehydrogenase , alcohol dehydrogenase and glycerol-3-phosphate dehydrogenase genes during the first 3 days of fermentation in sequential culture conditions are highlighted. Despite the complexity of correlating gene expression levels to acetic acid formation kinetics, we demonstrate that the acetic acid production pathway is altered by sequential culture conditions. Moreover, we show for the first time that the entire acetic acid and glycerol metabolic pathway can be modulated in by the presence of at the beginning of fermentation.