Flor yeast diversity and dynamics in biologically aged wines

One of the main plant defence mechanisms is the Systemic Acquired Resistance (SAR) mediated by Salicylic Acid (SA). This is a heightened and broad-spectrum immune response initiated by the exposure to pathogens, inducing resistance not only in the infected site, but also throughout the entire plant. It was demonstrated that plant immune system can be regulated by two classes of SA receptors: NONEXPRESSOR OF PR GENES 1 (NPR1) and NPR1-LIKE PROTEIN 3 and 4 (NPR3/NPR4). While NPR1 is required for SA-induction followed by the expression of pathogenesis-related (PR) protein and resistance against pathogens, NPR3/NPR4 serve as transcriptional co-repressors of SA-responsive genes.

Natural factors such as the environment in which the vine is grown play an important role in the quality of the wine. If you want to produce a good wine, it is indeed essential to produce quality grapes. To do this, we must enhance and optimize the terroir effect which, for the moment, plays a role that is not very well known. It is therefore essential, for example, to have scientifically established and well quantifiable relationships in order to have the system of areas of controlled origin accepted. R. Morlat (1989) and G. Seguin (1970) have already carried out studies on the role of certain soil factors on grape quality. In particular, they showed the importance of soil temperature and water content.

The synthetic herbicide glyphosate has been used extensively in viticulture over many decades to combat weeds. Despite this, the possible influence of residual glyphosate on both the alcoholic fermentation of grape juice and the subsequent metabolite profile of wines has not been investigated. In this study, Pinot noir juice supplemented with different concentrations of glyphosate (0 µg L-1, 10 µg L-1 and 1000 µg L-1) was fermented with commercial Saccharomyces cerevisiae yeast strains. Using a combination of analytical methods, 80 metabolites were quantified in the resulting wines.

L’étude présentée porte sur une commune de l’Entre-Deux-Mers dans le bordelais. Nous caractérisons dans un premier temps les potentialités des sols vis-à-vis de la production de vins rouges de qualité (délimitation de terroirs grâce à la prise en compte des couvertures pédologiques et des caractéristiques morphométriques du terrain : pentes, expositions, convexités. Dans un second temps, nous récapitulons l’évolution historique des occupations des sols depuis 1790 : l’emplacement des vignes est ainsi localisé sur les terroirs respectifs des communes. Enfin, une étude prospective résultant d’enquêtes sur l’utilisation du foncier, situe le devenir prévisible de l’espace étudié (en particulier dans ses composantes viticoles et urbaines).

Development of the indigenous microflora is not insignificant on the wine quality. S. cerevisiae indigenous strains are low tolerant to ethanol.