RT Journal Article
SR Electronic
T1 β-Glucosidase Activity and <em>bgl</em> Gene Expression of <em>Oenococcus oeni</em> Strains in Model Media and Cabernet Sauvignon Wine
JF American Journal of Enology and Viticulture
JO Am. J. Enol. Vitic.
FD American Society for Enology and Viticulture
SP 99
OP 105
DO 10.5344/ajev.2010.10044
VO 62
IS 1
A1 Nair Olguín
A1 Joan Oriol Alegret
A1 Albert Bordons
A1 Cristina Reguant
YR 2011
UL http://www.ajevonline.org/content/62/1/99.abstract
AB Strains of Oenococcus oeni performing malolactic fermentation might prove an interesting source of β-glucosidase enzymes, which can release aromatic volatile compounds from their flavorless glycoconjugate precursors present in wine. Many studies have been conducted using strains cultured in winelike media, but little is known about the activity of these strains in real wine. In this work, real Cabernet Sauvignon red wine was used as the culture medium to test β-glucosidase activity and bgl gene expression of four O. oeni strains. Assays in wine were compared with winelike medium and mixtures of wine and MRS broth medium. β-Glucosidase activity was detected in both whole-cell and supernatant fractions for all four strains tested, although results varied depending on the conditions. The highest activity was found in wine (4 U/mg) and the activity was inhibited in the presence of fructose. To measure bgl expression, the RNA of O. oeni was extracted directly from red wine for the first time. Using real-time qPCR, the relative expression of the bgl gene was evaluated. The expression of this gene varied depending on the strain and it was overexpressed in samples of wine diluted with MRS. These results could be of importance to the wine industry and in studies of strain adaptation to wine for the selection of starters.