Selección de cepas patagónicas de Oenococcus oeni y Lactobacillus plantarum en base a sus características enológicas

NATALIA BRIZUELA; BARBARA BRAVO FERRADA; ELIZABETH TYMCZYSZYN; LILIANA SEMORILE

Córdoba- Córdoba

Congreso; Congreso Internacional Cycitac; 2014

Cycitac

The use of starter cultures developed from strains of yeasts and lactic acid bacteria (LAB), indigenous to each production area, is a growing practice in the global wine industry. These ecotypical strains, better adapted to the agro-ecological characteristics of the region, besides presenting a greater capacity of competition than the foreign for successful control of fermentation processes, respect the typicity of terroir in wines, expressing the distinctive organoleptic characteristics. Selection of LAB for use as starter cultures for malolactic fermentation (MLF) is essentially based on a high malolactic activity under harsh conditions encountered. Further features to be taken into account correspond to interesting oenological properties such as the presence of enzymatic activities involved in the production of desirable wine aromas and the absence of biogenic amines production. Previous studies of LAB population diversity in Patagonian red wines showed that both O. oeni and Lb. plantarum are the major species present through spontaneous MLF. The aim of this study was to evaluate 27 Lb. plantarum and 27 O. oeni isolates obtained from a Patagonian Pinot noir in order to be used as possible MLF starter cultures. The isolates were identified by PCR/ ARDRA of 16S rRNA gene and sequence analysis of the same, and typified by RAPD-PCR using Coc primer. Four strains, belonging to different genetic clusters of each species, were selected to analyze their oenological properties. The ability to metabolize beneficial compounds and the capacity to synthesize deleterious compounds to wine was studied in the eight strains. Malolactic, β- glycosidase, tannase activity and other enzymatic activities involved in the production of desirable wine aromas and the absence of capacity for biogenic amines (BA) production, were studied. Also, the eight strains were genetically screened for enzyme-encoding genes using PCR with primers specific for β-glucosidase, citrate lyase, phenolic acid decarboxylase (PAD) and proline iminopeptidase. The results of PCR screening showed that the strains possessed different combinations of enzymes and that some strains did not possess any of the enzymes tested. The results showed that the properties analyzed are strain-dependent, and any of the strains studied showed the presence the hdc, tdc and ptcA genes. Lb. plantarum strains showed an increased enzymes production capacity of oenological interest than O. oeni strains. Based on the oenological properties analyzed, Lb. platarum strains were selected, and their capacity for malolactic consumption in laboratory scale winemaking were studied. All strains exhibited results which strongly suggest its potential as possible malolactic starter cultures.