Ana Isabel Briones

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Pulsed field electrophoresis is a suitable technique for differentiation of Saccharomyces cerevisiae strains. In this work, karyotype analysis was used to study the ecology of the wild S. Cerevisiae flora in musts in fermentation in the A.C. (Appellation Controlee) area of Valdepeñas (Spain). In order to do this, 392 colonies isolated from different vats in(More)
Enzymatic activity of potential interest in wine-making was studied for 182 non-Saccharomyces yeasts isolated from musts before and at the onset of fermentation at wine cellars operating under the La Mancha Appellation of Origin in Spain. Tests were carried out on plates containing differential substrates appropriate for each case (casein, gelatin,(More)
A total of 61 S. cerevisiae strains, 60 of them isolated from wine ecosystems, were evaluated for the presence of the gene encoding endopolygalacturonase (PGU1) and for polygalacturonase (PG) activity. Nine strains lack the gene PGU1 and did not exhibit PG activity on plate assays. Of the 52 strains showing an amplified band corresponding to the size of(More)
Yeasts are a group of microorganisms that belongs to the Fungal Kingdom. These unicellular fungi are distributed between the Basidiomycota and Ascomycota Phyla, being a paraphyletic group. Since 1865, its study has experienced a very important advance in terms of its understanding, characterization and taxonomic accommodation. Nevertheless, it is estimated(More)
Beta-glucosidase activity contributes to aroma formation during the winemaking process. This study investigated whether beta-glucosidase activity was expressed by wild Saccharomyces cerevisiae strains and by a laboratory strain. beta-Glucosidase activity was assayed on several culture media and under various growth conditions. The highest activities were(More)
Yeasts isolated from must before and during fermentation at a wine cellar of La Mancha region in Spain were characterised using Polymerase Chain Reaction / Restriction Fragments Lengths Polymorphism and Polymerase Chain Reaction / Temporal Temperature Gradient Gel Electrophoresis. S. cerevisiae strains were differentiated using mtDNA restriction analysis.(More)
In this work the actin gene was used to establish phylogenetic relationships of wider and more diffuse species of the genus Saccharomyces in food ecology by temporal temperature gradient electrophoresis (TTGE) and amplified restriction fragment length polymorphism (RFLP) analysis. Results for DNA RFLP analysis varied considerably, and some enzymes showed a(More)
A pectinolytic industrial yeast strain of Saccharomyces cerevisiae was generated containing the S. cerevisiae endopolygalacturonase gene (PGU1) constitutively expressed under the control of the 3-phosphoglycerate kinase gene (PGK1) promoter. The new strain contains DNA derived exclusively from yeast and expresses a high polygalacturonic acid hydrolyzing(More)
Wine is the result of the performance of different yeast strains throughout the fermentation in both spontaneous and inoculated processes. 22 Saccharomyces cerevisiae strains were characterized by microsatellite fingerprinting, selecting 6 of them to formulate S. cerevisiae mixed cultures. The aim of this study was to ascertain a potential benefit to use(More)
The aim of the present study was to select strains of yeast with good enological qualities which were adapted to the ecological surroundings of Guijoso Appellation of Origin (A.O). For this, 11 white and red vats from different grape varieties and stages of fermentation were studied, making a total of 28 samples, with a selection of 370 isolated yeasts.(More)