Search results for "Yeast in winemaking"

Adaptive evolution of wine yeast.

2003

Abstract Alcoholic fermentation is one of the main phases in wine production. It is usually conducted by yeasts belonging to the species Saccharomyces cerevisiae. Industrial S. cerevisiae strains are highly specialized organisms, which have evolved to utilize to their full potential the different environments or ecological niches. So, during the alcoholic fermentation, the yeast has been adapted to different kinds of stress conditions; this adaptation is call “domestication”. In this review, we describe the different mechanisms involved in the adaptive evolution of wine yeast strains.

Isolating Wine Yeasts that are Specific to the Apold Region and Identifying them through RFLP Genetic Methods

2015

The present study aims at isolating, identifying and selecting autochthonous wine yeast strains with a view to establish a crop bank specific to the Apold area. 569 wine yeast strains were isolated during the alcoholic fermentation of must from the Apold area, 458 were identified through cultural methods and with the help of the API 20 C AUX test (Biomeriux, France). Six yeast strains (A87, A169, A296, A314, A132 and A413) were genetically identified through the PCR-ITS RFLP method of the 5.8S-ITS segment; the resulting four strains were Saccharomyces cerevisiae - A87, A169, A296, A314 - and two Saccharomyces bayanus strains - A132 și A413. The strains we identified constitute a base for t…

Differences in the glucose and fructose consumption profiles in diverse Saccharomyces wine species and their hybrids during grape juice fermentation

2009

7 pages, 4 figures, 5 tables.

Rational selection of non-Saccharomyces wine yeasts for mixed starters based on ester formation and enological traits

2008

Thirty-eight yeast strains belonging to the genera Candida, Hanseniaspora, Pichia, Torulaspora and Zygosaccharomyces were screened for ester formation on synthetic microbiological medium. The genera Hanseniaspora and Pichia stood out as the best acetate ester producers. Based on the ester profile Hanseniaspora guilliermondii 11027 and 11102, Hanseniaspora osmophila 1471 and Pichia membranifaciens 10113 and 10550 were selected for further characterization of enological traits. When growing on must H. osmophila 1471, which displayed a glucophilic nature and was able to consume more than 90% of initial must sugars, produced levels of acetic acid, medium chain fatty acids and ethyl acetate, wit…

Molecular identification and characterization of wine yeasts isolated from Tenerife (Canary Island, Spain)

2007

Aims:  The present study was aimed at the identification, differentiation and characterization of indigenous yeasts isolated from Tenerife vineyards (viticulture region that has never been characterized before). Microbiota were studied from 14 samples taken during fermentations carried out in the 2002 vintage, from 11 wineries belonging to five wine regions on Tenerife Island. Methods and Results:  Yeasts’ strains were identified and characterized through restriction analysis of the 5·8S-internal transcribed spacer region and the mitochondrial DNA. At the beginning of alcoholic fermentation, 26 yeast species were found, where 14 species were present in significant frequencies in only one sa…

Characterization of wine yeast strains of the Saccharomyces genus on the basis of molecular markers: Relationships between genetic distance and geogr…

1996

Summary We identify and characterize 31 Saccharomyces strains from different wine regions, deposited at the Spanish Type Culture Collection, according to mtDNA restriction patterns and chromosomal profiles. By using this kind of information we analyze the correlation between genetic distances and ecological or geographical factors by means of a cluster analysis, assessed by an analysis of the molecular variance (AMOVA). From these analyses, red wine strains are significantly grouped according to their geographic origin, independently of the wine type and the grapevine cultivar, and white wine strians according to ecological factors (wine type of grapevine cultivars). This study also confirm…

Molecular Mechanisms Involved in the Adaptive Evolution of Industrial Yeasts

2006

Engineering a Saccharomyces cerevisiae Wine Yeast That Exhibits Reduced Ethanol Production during Fermentation under Controlled Microoxygenation Cond…

2006

ABSTRACTWe recently showed that expressing an H2O-NADH oxidase inSaccharomyces cerevisiaedrastically reduces the intracellular NADH concentration and substantially alters the distribution of metabolic fluxes in the cell. Although the engineered strain produces a reduced amount of ethanol, a high level of acetaldehyde accumulates early in the process (1 g/liter), impairing growth and fermentation performance. To overcome these undesirable effects, we carried out a comprehensive analysis of the impact of oxygen on the metabolic network of the same NADH oxidase-expressing strain. While reducing the oxygen transfer rate led to a gradual recovery of the growth and fermentation performance, its i…

Transcriptomic and proteomic insights of the wine yeast biomass propagation process

2010

Transcriptome and proteome profiles have been established for the commercial wine yeast strain T73 during an important industrial process: yeast biomass propagation. The data from both analyses reveal that the metabolic transition from fermentation to respiration is the most critical step in biomass propagation. We identified 177 ORFs and 56 proteins among those most expressed during the process, thus highlighting cell stress response, mitochondrial and carbohydrate metabolism as the most represented functional categories. A direct correlation between mRNA changes and protein abundance was observed for several functional categories such as tricarboxylic acid cycle proteins, heat shock prote…

Allelic variants of hexose transporter Hxt3p and hexokinases Hxk1p/Hxk2p in strains ofSaccharomyces cerevisiaeand interspecies hybrids

2015

The transport of sugars across the plasma membrane is a critical step in the utilization of glucose and fructose by Saccharomyces cerevisiae during must fermentations. Variations in the molecular structure of hexose transporters and kinases may affect the ability of wine yeast strains to finish sugar fermentation, even under stressful wine conditions. In this context, we sequenced and compared genes encoding the hexose transporter Hxt3p and the kinases Hxk1p/Hxk2p of Saccharomyces strains and interspecies hybrids with different industrial usages and regional backgrounds. The Hxt3p primary structure varied in a small set of amino acids, which characterized robust yeast strains used for the p…