| Popis: |
Prospection of yeasts from oenological environments can provide knowledge of new native strains that are capable of ferment must and positively influence the composition and sensory characteristics of the wine. This work is addressed to the biotechnological characterization of indigenous yeast of Tannat must, an emblematic and widespread vineyard of Uruguay. Fifty-three yeast strains were morphologically characterized and further identified by amplification and sequencing of ITS and D1-D2 regions, grouping into a total of fifteen species. A representative strain of each species was selected and evaluated for its technological traits. In presence of ethanol (6 to 16% v/v) and SO2 (40 mg/L), native Saccharomyces cerevisiae T19-3FS presented the best growth rates and minors lag phase. Of the non-Saccharomyces strains, S. bacillaris T19-3MS stood out for its behavior in vinification conditions, more closely related with Saccharomyces strains. S. cerevisiae T19-3FS, S. bacillaris T19-3MS, S. diversa T19-1FS and P. terricola T19-1FN conducted a successful fermentation process reaching final ethanol concentration ≥ 10% v/v, and showed K + R phenotype, highlighting its potential use in pure starter cultures for the production of finished wines. It also notes that S. diversa T19-1FS exhibits BGL activity making it interesting to explore its possible activity onto non-volatile glycosides during fermentation, to enhance aromatic compounds. Regarding the rest of the NS yeast studied, they could be good candidates for use in mixed-fermentations with Saccharomyces. |
