0000000000054704
AUTHOR
C. Charpentier
The plasma membrane ATPase of Kloeckera apiculata: purification, characterization and effect of ethanol on activity
Partially (6-fold) purified plasma membrane ATPase from an ethanol-sensitive yeast, Kloeckera apiculata, had an optimum pH of 6.0, an optimum temperature of 35°C, a K m of 3.6 mM ATP and a V max of 11 μmol Pi/min.mg protein. SDS-PAGE of the semi-purified plasma membrane showed a major band of 106 kDa. No in vivo activation of the ATPase by glucose was observed. Although 4% (v/v) ethanol decreased the growth rate by 50% it did not affect the ATPase. Concentrations of ethanol ≥2% (v/v) did, however, inhibit the enzyme in vitro. The characteristics of the enzyme did not change during growth in the presence of ethanol.
Dosage du sotolon au cours de l'élaboration des vins jaunes du Jura
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Sorption of aroma compounds to oak wood in wine ageing conditions
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Conditions optimales de formation du sotolon à partir de l'acide alpha-cétobutyrique dans le vin jaune du Jura
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Optimal Conditions for the Formation of Sotolon from .alpha.-Ketobutyric Acid in the French "Vin Jaune"
Sotolon (3-hydroxy-4,5-dimethyl-2(5H)-furanone) is a key flavor compound in the French flor-sherry Vin Jaune. Sotolon in Vin Jaune (120-268 microgram/L) is produced during the development of yeast film over a period of 6 years. In a synthetic medium resembling wine, the formation of sotolon was studied for different organic acids and acetaldehyde. Then, sotolon was quantified by HPLC on a Lichrospher 100 Diol column. Under the conditions of temperature, pH, and alcoholic content similar to the ageing of wine in barrels, sotolon was formed by a purely chemical mechanism from alpha-ketobutyric acid and acetaldehyde. The formation of sotolon increases by increasing temperature and decreasing p…
Quantification of sotolon in French "vins jaunes" during ageing under the yeast film
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Vinification des vins de voile, vin jaune, Xérès et autres
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Characterization of the production regions of Chardonnay wines by analysis of free amino acids
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Production de sotolon par les levures isolées des "vins jaunes" du Jura
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Le sotolon, marqueur de la typicité d'arôme des vins jaunes du Jura
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Ageing on lees ( sur lies ) and the use of speciality inactive yeasts during wine fermentation
Abstract: The chapter begins by describing the lees and autolysis phenomena: mechanism and released products. It then reviews the influence of ageing ‘ sur lies ’ on the organoleptic and hygienic properties and the stability of white, red and sparkling wines. The chapter includes a description of different yeast preparations mimicking the lees and their use in winemaking.