Isolation, selection and characterisation of microorganisms with potential to form unique consortium for wine production

The Defined Consortium of Wine Microorganisms was obtained from non-saccharomyces and saccharomyces yeasts and lactic acid bacteria isolated from places where autochthonous microflora can be expected to occur (grape berries, wine lees or cellar spaces). A total of 42 microorganisms were obtained by surface smears, fallouts from the air or isolation from fermented must. All isolates were then tested and the best strains were selected on the basis of technological and phenotypic characterization using standard microbiological techniques. The main criteria for the selection of strains were the ability to ferment and the production of organoleptically active compounds. Sulphur dioxide or ethanol tolerance, β-glucosidase activity, a taxonomic identification, the tendency to produce sulphane or the ability of lactic acid bacteria to perform malolactic fermentation were also considered. According to these results, the non-saccharomyces yeast Starmerella bacillaris, the saccharomyces yeast Saccharomyces cerevisiae and the lactic acid bacterium Levilactobacillus brevis were selected as part of the Defined Consortium of Wine Microorganisms.