Improving an Industrial Sherry Base Wine by Yeast Enhancement Strategies.

There is growing interest in yeast selection for industrial fermentation applications since it is a factor that protects a wine's identity. Although it is strenuous evaluating the oenological characteristics of yeasts in selection processes, in many cases the most riveting yeasts produce some undesirable organoleptic characteristics in wine. The aim of the present work is to improve an industrial yeast strain by reducing its hydrogen sulfide (HS) production.

Culturable Yeast Diversity of Grape Berries from ssp. (Gmelin) Hegi.

L. ssp. (Gmelin) Hegi is recognized as the dioecious parental generation of today's cultivars.

The Role of Yeasts as Biocontrol Agents for Pathogenic Fungi on Postharvest Grapes: A Review.

In view of the growing concern about the impact of synthetic fungicides on human health and the environment, several government bodies have decided to ban them. As a result, a great number of studies have been carried out in recent decades with the aim of finding a biological alternative to inhibit the growth of fungal pathogens. In order to avoid the large losses of fruit and vegetables that these pathogens cause every year, the biological alternative's efficacy should be the same as that of a chemical pesticide.

Culturable Yeasts as Biofertilizers and Biopesticides for a Sustainable Agriculture: A Comprehensive Review.

The extensive use of synthetic fertilizers and pesticides has negative consequences in terms of soil microbial biodiversity and environmental contamination. Faced with this growing concern, a proposed alternative agricultural method is the use of microorganisms as biofertilizers. Many works have been focused on bacteria, but the limited literature on yeasts and their potential ability to safely promote plant growth is gaining particular attention in recent years.

Rethinking about flor yeast diversity and its dynamic in the "criaderas and soleras" biological aging system.

Fino wine is one of the most important Sherry wines and it is obtained through a complex and dynamic biological aging system. In this study, wine and veil of flor samples from fifty-two barrels with different aging levels and distributed in three different wineries from the Jerez-Xèrés-Sherry winemaking area have been analyzed during two years. Some of the wine compounds most deeply involved in flor yeast metabolism were analyzed to take into account the blending effect of this system.

Bacteriophages as an Up-and-Coming Alternative to the Use of Sulfur Dioxide in Winemaking.

Certain acetic and lactic acid bacteria are major causes of quality defects in musts and wines, giving rise to defects such as a "vinegary," "sharp, like nail polish-remover" taste or preventing alcoholic and/or malolactic fermentation. Sulfur dioxide is the major tool currently used in the control of these bacteria in wine. The aim of this work was to isolate bacteriophages from musts and wine of different grape varieties that were able to eliminate lactic and acetic acid bacteria spoilages at the laboratory scale.

Wild Grape-Associated Yeasts as Promising Biocontrol Agents against Fungal Pathogens.

The increasing level of hazardous residues in the environment and food chains has led the European Union to restrict the use of chemical fungicides. Thus, exploiting new natural antagonistic microorganisms against fungal diseases could serve the agricultural production to reduce pre- and post-harvest losses, to boost safer practices for workers and to protect the consumers' health. The main aim of this work was to evaluate the antagonistic potential of epiphytic yeasts against , and pathogen species.

New Genes Involved in Osmotic Stress Tolerance in .

Adaptation to changes in osmolarity is fundamental for the survival of living cells, and has implications in food and industrial biotechnology. It has been extensively studied in the yeast , where the Hog1 stress activated protein kinase was discovered about 20 years ago. Hog1 is the core of the intracellular signaling pathway that governs the adaptive response to osmotic stress in this species.

Rapid and not culture-dependent assay based on multiplex PCR-SSR analysis for monitoring inoculated yeast strains in industrial wine fermentations.

Wine industry needs a simple method for rapid diagnosis of the dominance of inoculated strains that could be performed routinely during the fermentation process. We present a suitable, high-throughput, and low-cost method to monitor rapidly the dominance of inoculated yeast strains in industrial fermentations of red and white wines using an activated carbon cleaning pretreatment, and a rapid DNA extraction method plus multiplex PCR-SSR analysis. We apply this technique directly to samples of fermenting wines without previously isolating yeast colonies.

A long term field study of the effect of fungicides penconazole and sulfur on yeasts in the vineyard.

This research deals with how two fungicide treatments against powdery mildew, penconazole as a systematic fungicide and sulfur as an inorganic broad-spectrum fungicide, affect the diversity and density of wine yeasts associated with grape berry surfaces and subsequent spontaneous fermentations. Unlike other studies in this area, this work aims to evaluate this effect on the population dynamics in the environment, the conditions of which are not reproducible in the laboratory. A long term (three year) sampling plan was thus devised.

Novel wine yeast with mutations in YAP1 that produce less acetic acid during fermentation.

Acetic acid, a byproduct formed during yeast alcoholic fermentation, is the main component of volatile acidity (VA). When present in high concentrations in wine, acetic acid imparts an undesirable 'vinegary' character that results in a significant reduction in quality and sales. Previously, it has been shown that saké yeast strains resistant to the antifungal cerulenin produce significantly lower levels of VA.

Influence of different floor management strategies of the vineyard on the natural yeast population associated with grape berries.

Some oenological practices, such as the massive utilisation of commercial yeast and the consequent colonisation of wineries, can contribute to reducing the native yeast biodiversity. In this context, the vineyard could be a reservoir of autochthonous yeasts of oenological interest. Thus, the evaluation of the influence of different agricultural parameters on the biodiversity of yeast population in the vineyard is necessary.

Remanence and survival of commercial yeast in different ecological niches of the vineyard.

The use of commercial wine yeast strains as starters has been grown extensively over the past three decades. Wine yeasts are annually released in winery environments; however, little is known about the fate of these strains in the vineyard. To evaluate the industrial starter yeasts' ability to survive in nature and become part of the natural microbiota of musts, commercial yeast was disseminated voluntarily in an experimental vineyard in the Madrid region (Spain).

Influence of the farming system and vine variety on yeast communities associated with grape berries.

Wine production in most countries is based on the use of commercial strains leading to the colonisation of the wineries by these strains with the consequent reduction of autochthonous biodiversity. This implies that wine styles could therefore become standardised. The vineyard could be an important source of native yeasts of oenological interest.