Technological properties of Oenococcus oeni strains   isolated from typical southern Italian wines.
OBJECTIVE
To isolate indigenous Oenococcus oeni strains suitable as starters for malolactic fermentation (MLF), using a reliable polyphasic approach.


RESULTS
Oenococcus oeni strains were isolated from Nero di Troia wines undergoing spontaneous MLF. Samples were taken at the end of alcoholic fermentation and during MLF. Wine samples were diluted in a sterile physiological solution and plated on MRS and on modified FT80. Identification of O. oeni strains was performed by a polymerase chain reaction (PCR) experiment using strain-specific primers. Strains were further grouped using a multiplex RAPD-PCR analysis. Then, six strains were inoculated in two winelike media with two different ethanol concentrations (11 and 13% vol / vol) with a view to evaluate their capacity to grow and to perform MLF. In addition, a quantitative PCR (qRT-PCR) approach was adapted to monitor the physiological state of the strains selected.


CONCLUSIONS
A positive correlation between the malolactic activity performance and the ability to develop and tolerate stress conditions was observed for two selected O. oeni strains.


CONCLUSIONS
The results reported are useful for the selection of indigenous MLF starter cultures with desired oenological traits from typical regional wines. It should be the base for the improvement in organoleptic quality of typical red wine.
Capozzi
V
V
Dipartimento di Scienze degli Alimenti, Facoltà di Agraria, Foggia, Italy.
Russo
P
P
Beneduce
L
L
Weidmann
S
S
Grieco
F
F
Guzzo
J
J
Spano
G
G
D000431:Ethanol / Q000378:metabolism; D005285:Fermentation; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000378:metabolism; D008293:Malates / Q000378:metabolism*; D056585:Oenococcus / Q000254:growth & development / Q000302:isolation & purification* / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D019105:Random Amplified Polymorphic DNA Technique; D013312:Stress, Physiological; D013447:Sulfites / Q000378:metabolism; D014920:Wine / Q000382:microbiology*
D008293:Malates; D013447:Sulfites; D019344:Lactic Acid; D000431:Ethanol; C030298:malic acid