Selection and characterization of a Patagonian Pichia kudriavzevii for wine deacidification.
OBJECTIVE
The purpose of this study was to select autochthonous yeasts with metabolic ability to degrade L-malic acid for its potential use in young wine deacidification.


RESULTS
Fifty seven Patagonian nonSaccharomyces yeast of oenological origin were identified by conventional molecular methods and tested in their capability to grow at the expense of L-malic acid. Only four isolates belonging to Pichia kudriavzevii species showed this property, and one of them was selected to continue with the study. This isolate, named as P. kudriavzevii ÑNI15, was able to degrade L-malic acid in microvinifications, increasing the pH 0·2-0·3 units with a minimal effect on the acid structure of wine. Additionally, this isolate produced low levels of ethanol, important levels of glycerol (10·41 ± 0·48 g l(-1) ) and acceptable amounts of acetic acid (0·86 ± 0·13 g l(-1) ). In addition, it improved the sensorial attributes of wine increasing its fruity aroma.


CONCLUSIONS
The selection of yeasts for oenological use among nonSaccharomyces species led to the finding of a yeast strain with novel and interesting oenological characteristics which could have significant implications in the production of well-balanced and more physicochemical and microbiological stable young wines.


CONCLUSIONS
The use of P. kudriavzevii ÑNI15 as mixed starter with S. cerevisiae would eliminate the cultural and cellar operations undertaken to adjust the musts acidity, therefore improving wine quality and reducing production costs.
Grupo de Enología, Facultad de Ingeniería, Instituto de Investigación y Desarrollo en Ingeniería de Procesos, Biotecnología y Energías Alternativas (PROBIEN - Consejo Nacional de Investigaciones Científicas y Técnicas, CONICET), Facultad de Ingeniería, Universidad Nacional del Comahue (UNCo), Neuquén, Argentina.
S M
SM
Del Mónaco
N B
NB
Barda
N C
NC
Rubio
A C
AC
Caballero
D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D008293:Malates / Q000378:metabolism*; D010843:Pichia / Q000378:metabolism*; D012441:Saccharomyces cerevisiae / Q000378:metabolism; D014920:Wine / Q000382:microbiology*; D015003:Yeasts / Q000302:isolation & purification / Q000378:metabolism
D008293:Malates; C030298:malic acid
indigenous Saccharomyces cerevisiae; malic acid; nonSaccharomyces diversity; wine aroma; wine yeast