Amparo Querol

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The identification and classification of yeasts have traditionally been based on morphological, physiological and biochemical traits. Various kits have been developed as rapid systems for yeast identification, but mostly for clinical diagnosis. In recent years, different molecular biology techniques have been developed for yeast identification, but there is(More)
A simple and rapid method of yeast strain characterization based on mitochondrial DNA restriction analysis was applied to the control of wine fermentations conducted by active dry yeast strains. This molecular approach allows us to understand several important aspects of this process, such as the role of the active dry yeast strain and that of the natural(More)
In this study, we identified a total of 33 wine yeast species and strains using the restriction patterns generated from the region spanning the internal transcribed spacers (ITS 1 and 2) and the 5.8S rRNA gene. Polymerase chain reaction (PCR) products of this rDNA region showed a high length variation for the different species. The size of the PCR products(More)
Along the fermentation process yeasts are affected by a succession of stress conditions that affect their viability and fermentation efficiency. Among the stress conditions the most relevant are high sugar concentration and low pH in musts, temperature and, as fermentation progresses, ethanol accumulation. Nowadays, due to the demanding nature of modern(More)
Wine yeast strains show a high level of chromosome length polymorphism. This polymorphism is mainly generated by illegitimate recombination mediated by Ty transposons or subtelomeric repeated sequences. We have found, however, that the SSU1-R allele, which confers sulfite resistance to yeast cells, is the product of a reciprocal translocation between(More)
Natural strains of Saccharomyces cerevisiae are prototrophic homothallic yeasts that sporulate poorly, are often heterozygous, and may be aneuploid. This genomic constitution may confer selective advantages in some environments. Different mechanisms of recombination, such as meiosis or mitotic rearrangement of chromosomes, have been proposed for wine(More)
Using mitochondrial DNA restriction endonuclease analysis, the dynamics of the natural Saccharomyces cerevisiae strains present in spontaneous wine fermentations have been studied. We observed a sequential substitution of Sacch. cerevisiae strains along fermentation agreeing with different fermentation phases. When the restriction pattern's similarity(More)
AIMS To study the diversity and dynamics of indigenous Saccharomyces wine populations during Malbec spontaneous fermentation, a representative Patagonian red wine, at both industrial and laboratory scale. METHODS AND RESULTS Two molecular techniques, including restriction fragment length polymorphism of mitochondrial (mt) DNA and polymorphism of amplified(More)
A rapid method based on mtDNA restriction analysis is described for yeast strain identification. The method is an adaptation of that devised by Querol et a]. [Syst. Appl. Microbiol. 15 (1992) 439] for Saccharomyces cerevisiae wine strains, and consists of the standard miniprep isolation of yeast total DNA, and the use of restriction endonucleases that(More)
Table olives are a traditional fermented vegetable of the Mediterranean countries, but their production and consumption are now spread all around the world. Yeasts can play a double role in this food. They are present throughout the fermentative process and it is generally accepted that they can produce compounds with important organoleptic attributes(More)