Yeast and filamentous fungi microbial communities in organic red grape juice : effect of vintage, maturity stage, SO2, and bioprotection

Changes are currently being made to winemaking processes to reduce chemical inputs [particularly sulfur dioxide (SO2)] and adapt to consumer demand. In this study, yeast growth and fungal diversity were investigated in merlot during the prefermentary stages of a winemaking process without addition of SO2. Different factors were considered, in a two-year study: vintage, maturity level and bioprotection by the adding yeast as an alternative to SO2. The population of the target species was monitored by quantitative-PCR, and yeast and filamentous fungi diversity was determined by 18S rDNA metabarcoding. A gradual decrease of the α-diversity during the maceration process was highlighted. Maturity level played a significant role in yeast and fungal abundance, which was lower at advanced maturity, while vintage had a strong impact on Hanseniaspora spp. population level and abundance. The presence of SO2 altered the abundance of yeast and filamentous fungi, but not their nature. The absence of sulfiting led to an unexpected reduction in diversity compared to the presence of SO2, which might result from the occupation of the niche by certain dominant species, namely Hanseniaspora spp. Inoculation of the grape juice with non-Saccharomyces yeast resulted in a decrease in the abundance of filamentous fungi generally associated with a decline in grape must quality. Lower abundance and niche occupation by bioprotection agents were observed at the overripened stage, thus suggesting that doses applied should be reconsidered at advanced maturity. Our study confirmed the bioprotective role of Metschnikowia pulcherrima and Torulaspora delbrueckii in a context of vinification without sulfites

Décomposition en ondelettes de maillages triangulaires 3D irrégulièrement subdivisés. Application à la compression

- Nous proposons un nouvel algorithme de subdivision qui permet la simplification des maillages triangulaires quelconques à l'aide de la transformée en ondelettes. Cet algorithme est appliqué à la compression sans pertes des maillages. Des résultats expérimentaux montrent l'efficacité de cette approche dans des représentations multirésolutions

Non-Saccharomyces yeasts as bioprotection in the composition of red wine and in the reduction of sulfur dioxide

Non-Saccharomyces yeasts have been used for many years due to their technological potential, particularly as a « booster » of wine fruity aroma in mixed fermentations with Saccharomyces cerevisiae. Recently, a new application has emerged, bioprotection, which consists in colonizing the environment in the context of sulfite reduction in wines. The chemical and sensory impact of non-Saccharomyces yeast according to different modes of application in a context of fermentation without addition of SO2 was evaluated through trial with Merlot N. (Vitis vinifera L.). An effective niche occupation by non-Saccharomyces yeasts was highlighted during the prefermentary stages by Quantitative-PCR and MALDI-TOF MS identification. Chemical analysis (GC-MS and GC MS/MS) of finish wine showed the significant impact of the dose applications, with bioprotection characterized by linear esters and sequential application by acetates of higher alcohol contents. Moreover, a separation according to the species used in bioprotection was revealed. Finally, using a panel trained, the sensory analysis confirmed that the use of non-Saccharomyces yeast was a fruity booster in sequential inoculation and, to a less extent, when used as bioprotection. This study shows for the first time that the use of non-Saccharomyces yeast as a bioprotection has a significant impact on the aromatic profile of wines

Ancient DNA and kinship analysis of human remains deposited in Merovingian necropolis sarcophagi (Jau Dignac et Loirac, France, 7th-8th century AD)

International audienc

Bioprotection as an alternative to SO₂ in the pre-fermentation phase

Additives have been used in the food industry for many years, to prevent food spoilage and extend shelf life. These chemical additives are a source of controversy and their use must be reduced in the face of societal demand. In enology, this applies in particular to sulfur dioxide (SO2). There has been recent research on bioprotection as an alternative to sulfite addition in the pre-fermentation phase. This technical article discusses the many advantages of using bioprotection agents

Mitigating the effects of climate change on berry composition by canopy management

Oral presentatio

Pouvoirs des familles, familles de pouvoir

La famille constitue depuis longtemps un objet d’étude privilégié des historiens des sociétés. Ayant abandonné l’attention presque exclusive accordée autre­fois aux seuls lignages aristocratiques voire royaux, cette histoire de la famille a connu depuis un demi-siècle de profonds renouvellements, tant thématiques que méthodologiques. Directement impliquée dans l’histoire quantitative, notamment par le biais de la « reconstruction des familles », la thématique familiale s’est retrouvée au centre de l’histoire des mentalités. Ultérieurement enfin, via l’importation de problématiques venues des autres sciences sociales et le recours à la démarche « micro-historique », la famille s’est muée en un espace social et anthropologique au sein duquel sont mises à jours les dynamiques qui affectent ces réalités familiales. Dans le même temps, ces réflexions sur le passé d’une réalité sociale toujours vivante viennent en écho aux interrogations contemporaines sur le devenir de la famille nucléaire. La « crise » d’un modèle familial pluriséculaire et les recompositions familiales auxquelles elles donnent lieu placent ces réflexions sur la famille au cœur d’un débat de société particulièrement intense. Dans ce contexte qui fait de la famille un sujet d’actualité brûlant, le colloque organisé à Toulouse a voulu dresser un bilan des travaux les plus récents des meilleurs spécialistes du sujet, il s’est inscrit dans une démarche délibérément comparatiste tout en insistant sur les continuités et les ruptures identifiables tant en termes de problématiques, de démarches que de résultats. Compte tenu de la spécificité du laboratoire à l’origine de cette réflexion, le comparatisme concerne essentiellement les espaces français et ibérique, ce dernier étant compris au sens large puisqu’il intègre les sociétés coloniales ibéro-américaines. Dans le même temps, ce colloque a fait le choix de la transdisciplinarité et de la longue durée, depuis le bas Moyen-Âge jusqu’au xxe siècle. Cette longue phase chronologique coïncide avec l’émergence puis le développement de la structure nucléaire, modèle familial précisément en cours de redéfinition aujourd’hui. À son propos, leurs auteurs y confrontent des approches historiques, sociologiques, anthropologiques et juridiques qui toutes éclairent les complexités de cette histoire tout en contextualisant les interroga­tions contemporaines

The Mediterranean region under climate change

This book has been published by Allenvi (French National Alliance for Environmental Research) to coincide with the 22nd Conference of Parties to the United Nations Framework Convention on Climate Change (COP22) in Marrakesh. It is the outcome of work by academic researchers on both sides of the Mediterranean and provides a remarkable scientific review of the mechanisms of climate change and its impacts on the environment, the economy, health and Mediterranean societies. It will also be valuable in developing responses that draw on “scientific evidence” to address the issues of adaptation, resource conservation, solutions and risk prevention. Reflecting the full complexity of the Mediterranean environment, the book is a major scientific contribution to the climate issue, where various scientific considerations converge to break down the boundaries between disciplines