Characterization and technological properties of Oenococcus oeni isolates associated to Patagonian Pinot noir grapes

BRAVO FERRADA, B; HOLLMANN, A; DELFEDERICO, L; VALEZ LA HENZ, D; CURYLEN, Y; CABALLERO, A; SEMORILE, L

MONTEVIDEO, URUGUAY

Congreso; XX Congreso Latinoamericano de Microbiología; 2010

In present work the red wine Pinot noir variety, 2008 vintage, from Patagonian region was monitored, and several different lactic acid bacteria were isolated. By analysis of a fragment of rpoB gene, species-specific PCR of malolactic enzyme, and sequence of 16-rRNA gene, three isolates were identified as Oenococcus oeni. Polyphasic typing made by carbohydrate fermentation behaviour and RAPD-PCR grouped the isolates and O. oeni reference strain in three different clusters. With the aim to evaluate the possibility of use those indigenous O. oeni isolates as malolactic starters, the ethanol tolerance and malolactic activity were studied. All isolates were able to growth in all ethanol concentration tested (6, 10 and 14%). After 220 h, cell mass of three isolates growing in MRS-TJ supplemented with 6 and 10% of ethanol reached values very similar to those obtained under optimal conditions, but higher alcohol con centration (14%) produced a partial decrease in the cell mass. Finally when malolactic activity was assayed it was observed that three O. oeni isolates were able to exhaust the malic acid content in the media after 84 h of incubation. Furthermore, a clear correlation between OD600 and malolactic activity was also found. The O. oeni isolates obtained were well characterized showing phenotypic and genotypic differences. The results presented above suggest that three isolates could be used as starter cultures in winemaking of Pinot noir variety.