Search results for "Making"
showing 10 items of 1218 documents
Screening of Hanseniaspora Strains for the Production of Enzymes with Potential Interest for Winemaking
2015
Some non-Saccharomyces yeasts, including Hanseniaspora, participate in the first stages of wine fermentation. Besides their importance in the wine production process some of these yeasts have been described to be potential producers of hydrolytic enzymes to industrial level. In this work, we pretend to evaluate the technological abilities of the Hanseniaspora strains deposited in the Spanish Type Culture Collection (CECT). First of all, we considered verification of the correct identification of the strains using several miniaturized biochemical systems and molecular techniques (PCR, RFLP and sequencing of the ribosomal D1/D2 region). The results allowed us to verify the correct adscription…
Stress response and expression patterns in wine fermentations of yeast genes induced at the diauxic shift
2000
During wine fermentation yeasts quickly reach a stationary phase, where cells are metabolically active by consuming sugars present in grape must. It is, consequently, of great interest at this stage to identify suitable gene promoters that may be used to induce the expression of genes with enological applications. With this aim, we have studied a group of genes showing an induction peak at the diauxic shift, and possessing stress response elements (STRE) at their promoters. We have determined their induction levels under individualized stress conditions, such as carbon source starvation or high salt concentrations. In all the cases studied, the activation and/or basal transcription are depe…
A comparative study of the wine fermentation performance of Saccharomyces paradoxus under different nitrogen concentrations and glucose/fructose rati…
2010
8 pages, 1 figure, 4 tables.-- Online version published: May 2009.-- The definitive version is available at www3.interscience.wiley.com
Selection and molecular characterization of wine yeasts isolated from the ‘El Penedès’ area (Spain)
2000
Abstract A study of the microbiota present during the wine fermentation of five grape varieties from the ‘El Penedes’ area (Spain) was carried out to select autochthonous yeast strains for industrial wine production. In this study we identified members of the genera Candida, Dekkera, Hanseniaspora, Kluyveromyces, Torulaspora, Zygosaccharomyces and Saccharomyces in wine fermentation microbiota. Strains of Saccharomyces cerevisiae, as responsible agents of the alcoholic fermentation, were considered for a selection protocol. In this work we applied different enological criteria for selection, but previously we have characterized and differentiated Saccharomyces isolates by molecular methods t…
Amino acids and volatile compounds in wines from Cabernet Sauvignon and Tempranillo varieties subjected to malolactic fermentation in barrels
2012
The aim of the present paper is to compare the behaviour of industrial lactic bacteria and indigenous bacteria of the cellar when malolactic fermentation was carried out in barrels. The effects of these bacteria on the concentration of metabolised amino acids during malolactic fermentation and on the composition of volatile compounds both before and after malolactic fermentation are studied. The experiment was performed with wines of the Tempranillo and Cabernet Sauvignon varieties. An analysis has been made of the easily extractable volatile compounds of the wood and the compounds from the grapes, and the action of the yeasts during the alcoholic fermentation. Acetoin and diacetyl decreas…
Aroma compounds in wine as influenced by apiculate yeasts
1996
Aroma compounds of wines resulting from fermentation of sterile grape musts from Monastrell variety inoculated with pure and mixed cultures of apiculate and Saccharomyces yeasts, were isolated and analyzed by gas chromatography with flame ionization and mass spectrometry. Samples fermented with mixed cultures produced a higher concentration of selected compounds and higher total amounts of alcohols and acids, in contrast with wines produced with pure cultures of Saccharomyces spp. Apiculate yeasts are important in the chemical composition and quality of wine.
Surface properties of Saccharomyces cerevisiae lees during sparkling wine ageing and their effect on flocculation
2009
Cell surface properties were determined for the first time for lees of Saccharomyces cerevisiae, and they proved to be significantly dependent on the time of sparkling wine ageing on lees. Cell surface hydrophobicity decreased from approximately 44% to 11% of affinity to hexadecane. Electron acceptor capacity (calculated as % affinity to ethyl acetate-% affinity to decane) increased from approximately -27% to 10 % and zeta potential from approximately -4 to 6mV. Mannoproteins are released from the external cell wall layer during the autolytic process, as confirmed by TOF-SIMS analysis of the cell wall chemical composition. This could explain the modifications of lees cell surface properties…
Saccharomyces Yeasts I
2011
Publisher Summary This chapter discusses the microbiological aspects of saccharomyces yeasts in wine production. Yeasts, which play a central role in the winemaking process, are unicellular fungi that reproduce by budding. Most yeast belongs to the phylum Ascomycota on the basis of their sexual development. The selection of wine yeasts with specific genetic markers provides a system for the precise monitoring of the growth of particular strains during fermentation. Analyses of this type have shown that fermentation is driven mainly by inoculated yeasts, although these sometimes become only partially established. The growth of the natural flora is not completely suppressed during the initial…
Intraspecific biodiversity and 'spoilage potential' of Brettanomyces bruxellensis in Apulian wines
2015
Abstract The yeast Brettanomyces bruxellensis, generally considered the main oenological spoilage microbe, is able to survive during the winemaking process and it confers off-odors to wine, in reason of its ability to produce considerable amounts of volatile phenols. Forty-eight isolates of B. bruxellensis, obtained from several wines collected in Apulia (Southern Italy), were genetically characterized using an integrated approach, including a strain biodiversity analysis by Sau-PCR. Furthermore, the production of volatile phenols was assessed in wine and in synthetic medium, confirming the oenological spoilage potential of the analysed strains. Our findings indicate a remarkable genetic va…
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.