Search results for "Fermentació"
showing 10 items of 22 documents
Aproximaciones para mejorar el crecimiento de bacterias lácticas iniciadoras OM13 durante las primeras etapas de producción de aceitunas verdes de me…
2018
The present research aimed at determining the optimal conditions for the lactic acid fermentation of green Spanish-style table olives. The work is a follow-up, and focuses on the performance of the commercial starter strain Lactobacillus pentosus OM13 by applying an acclimatization step and the addition of nutrients, and concentrations of lactic acid that were previously investigated. The acclimatization of the cells warranted the dominance of the starter culture even at an inoculation level of 2 Log cycles lower than that commonly used in standard fermentation. A significant effect was found in terms of acidification kinetics within the first week of fermentation, with the highest decrease…
Effect of temperature on the prevalence of Saccharomyces non-cerevisiae species against a S. cerevisiae wine strain in wine fermentation: competition…
2017
Saccharomyces cerevisiae is the main microorganism responsible for the fermentation of wine. Nevertheless, in the last years wineries are facing new challenges due to current market demands and climate change effects on the wine quality. New yeast starters formed by non-conventional Saccharomyces species (such as S. uvarum or S. kudriavzevii) or their hybrids (S. cerevisiae x S. uvarum and S. cerevisiae x S. kudriavzevii) can contribute to solve some of these challenges. They exhibit good fermentative capabilities at low temperatures, producing wines with lower alcohol and higher glycerol amounts. However, S. cerevisiae can competitively displace other yeast species from wine fermentations,…
The Use of Mixed Populations of Saccharomyces cerevisiae and S. kudriavzevii to Reduce Ethanol Content in Wine: Limited Aeration, Inoculum Proportion…
2017
Saccharomyces cerevisiae is the most widespread microorganism responsible for wine alcoholic fermentation. Nevertheless, the wine industry is currently facing new challenges, some of them associate with climate change, which have a negative effect on ethanol content and wine quality. Numerous and varied strategies have been carried out to overcome these concerns. From a biotechnological point of view, the use of alternative non-Saccharomyces yeasts, yielding lower ethanol concentrations and sometimes giving rise to new and interesting aroma, is one of the trendiest approaches. However, S. cerevisiae usually outcompetes other Saccharomyces species due to its better adaptation to the fermenta…
Caracterización enológica y molecular de híbridos naturales y artificiales entre las especies saccharomyces cerevisiae y saccharomyces kudriavzevii
2018
La industria enológica debe dar respuesta a las nuevas demandas del consumidor, así como responder ante los cambios en la materia prima(mosto) debidos al cambio climático, de gran repercusión en la calidad y aceptación del vino. Para ello se exigen cambios en las prácticas enológicas como el desarrollo de cultivos iniciadores de levaduras adaptadas a las nuevas condiciones de fermentación como son las bajas temperaturas para obtener vinos más aromáticos o el desarrollo de levaduras que produzcan más aromas, mayor concentración de glicerol y menos etanol. S. cerevisiae se ha descrito como la especie predominante en la fermentación alcohólica; sin embargo, otras especies del género Saccharomy…
Caracterización de los compuestos aromáticos en embutidos crudos curados y estudio de los factores que afectan a su generación.
2007
207 páginas.-- Tesis Doctoral del Departament de Medicina Preventiva i Salut Pública, Ciències de l'Alimentació, Toxicologia i Medicina Legal de l'Universitat de València (UV) y del Departamento de Ciencia de los Alimentos del Instituto de Agroquímica y Tecnología de los Alimentos (IATA-CSIC).-- Fecha de defensa: 30/05/2007.
Protective role of glutathione addition against wine-related stress in Oenococcus oeni
2016
FIliació URV: SIInclòs a la memòria: SI Oenococcus oeni is the main species responsible for the malolactic fermentation (MLF) of wine due to its ability to survive in this environment. Some wine-related stress factors, such as ethanol and low pH, may alter the cell redox balance of O. oeni. For the first time, the ability to uptake glutathione (GSH), an almost universal tripeptide with antioxidant properties, has been associated to the improvement of stress response in O. oeni. Despite the inability of O. oeni to synthesize GSH, this bacterium can capture it from the media. The ability of 30 O. oeni strains to uptake GSH was assessed in this study. Although all of the strains tested were ab…
Stabilization process in Saccharomyces intra- and interspecific hybrids in fermentative conditions
2015
© 2015 Sociedad Española de Microbiologia. All rights reserved. We evaluated the genetic stabilization of artificial intra- (Saccharomyces cerevisiae) and interspecific (S. cerevisiae × S. kudriavzevii) hybrids under wine fermentative conditions. Large-scale transitions in genome size and genome reorganizations were observed during this process. Interspecific hybrids seem to need fewer generations to reach genetic stability than intraspecific hybrids. The largest number of molecular patterns recovered among the derived clones was observed for intraspecific hybrids, particularly for those obtained by rare-mating. Molecular marker analyses revealed that unstable clones could change during the…
Molecular and enological characterization of a natural Saccharomyces uvarum and Saccharomyces cerevisiae hybrid
2015
Available online 17 March 2015
Mitotic Recombination and Genetic Changes in Saccharomyces cerevisiae during Wine Fermentation
2000
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 strains. We studied the stability of the URA3 locus of a URA3/ura3 wine yeast in consecutive grape must fermentations. ura3/ura3 homozygotes were detected at a rate of 1 x 10(-5) to 3 x 10(-5) per generation, and mitotic rearrangements for chromosomes VIII and XII appeared after 30 mitotic divisions. We used the karyotype as a meiotic marker an…
Physiological and genomic characterisation of Saccharomyces cerevisiae hybrids with improved fermentation performance and mannoprotein release capaci…
2015
Yeast mannoproteins contribute to several aspects of wine quality by protecting wine against protein haze, reducing astringency, retaining aroma compounds and stimulating lactic-acid bacteria growth. The selection of a yeast strain that simultaneously overproduces mannoproteins and presents good fermentative characteristics is a difficult task. In this work, a Saccharomyces cerevisiae × S. cerevisiae hybrid bearing the two oenologically relevant features was constructed. According to the genomic characterisation of the hybrids, different copy numbers of some genes probably related with these physiological features were detected. The hybrid shared not only a similar copy number of genes SPR1…