Freeze-Drying of Wine Yeasts and Oenococcus oeni and Selection of the Inoculation Conditions after Storage

ALE CE; OTERO M. C.; PASTERIS, S.E.

Journal of Bioprocessing & Biotechniques

OMICS International

Año: 2015 vol. 05 p. 1 - 8

Modern winemaking industry has new challenges focused on the application of preserved starter?s microbialcultures for the optimization of the fermentation process that ensuring flavor characteristics and the reproducibilityof the final products obtained. Thus, the aim of the present work was to select the inoculation conditions for preselectedSaccharomyces cerevisiae mc2 (SC), Kloeckera apiculata mF (KA) and Oenococcus oeni X2L (OO) afterfreeze-drying and storage in both pure and mixed cultures. The strains were grown in 17% Natural Grape Juice (NGJ)and then lyophilized in 10% individual sugars (glucose, fructose, sucrose, maltose and trehalose), 2.4% sodiumglutamate, 4% yeast extract and NGJ by using different culture combinations: 1)- pure cultures (KA1, SC1, OO1),2)- mixed yeast cultures (KA2, SC2), 3)- mixed microbial cultures (KA3, SC3, OO3). After lyophilization, the strainswere stored for 12 months at 4 and 25°C. Viability post-lyophilization was culture/lyoprotectant-dependent whilesurvival to storage depended on time and temperature being O. oeni the more resistant strain to the all process, thenK. apiculata and S. cerevisiae, respectively. Freeze-drying of mixed KA-SC in 10% fructose and OO in 17% NGJup to 6 months of storage at 4°C were the best conditions for the maintenance of the fermentative properties of thestrains and for glycerol production. The inoculation of grape musts with KA-SC and OO lyophilized individually withlow-cost lyoprotectants would ensure the proper development of the fermentation processes and glycerol synthesis,thus increasing the organoleptic characteristics of wines by a non-Saccharomyces strain. Therefore, the starterculture should include K. apiculata, S. cerevisiae and O. oeni strains.