17 research outputs found
Unravelling the role of lactic acid bacteria on sparkling wine elaboration through metabolomics approach
Grape berry bacterial microbiota: Impact of the ripening process and the farming system
cited By 24International audienceno abstrac
Comparison of the effect of pulsed electric field or high voltage electrical discharge for the control of sweet white must fermentation process with the conventional addition of sulfur dioxide
International audienceThe present work discusses the efficiency of pulsed electrical treatments for the inactivation of yeasts. The application of pulsed electric fields (PEFs) and high voltage electrical discharges (HVEDs) as alternatives to sulfites, which are used as anti-microbial to stop the fermentation of sweet white wine, was investigated. The influence of sulfite concentration (from 0 mg.L-1 to 500 mg.L-1), PEF (from 4 kV.cm(-1) to 20 kV.cm(-1); from 0.25 ms to 6 ms) and HVED (40 kV/cm; 1 ms or 4 ms) treatments on the inactivation of total yeasts and non-Saccharomyces yeasts was determined. The addition of SO2 (250 mg.L-1) resulted in 8 log total yeast reduction. The maximum yeast inactivation obtained with PEF and HVED was respectively 3 and 4 logs. The use of SO2, HVED and PEF allows decreasing the non-Saccharomyces yeast level by 7, 5 and 4 logs respectively. However, the wine browning was less pronounced for the samples treated by PEF in comparison with HVED and SO2 treatments. PEF seems to be the most suitable alternative technique to sulfite addition
Evaluating the influence of operational parameters of pulsed light on wine related yeasts: focus on inter- and intra-specific variability sensitivity
In oenology, there is a growing demand by consumers for wines produced with less inputs (such as sulphite, frequently used for microbial control). Emerging control methods for managing microorganisms in wine are widely studied. In this study, the efficiency of pulsed light (PL) treatment was investigated. A drop-platted system was used to evaluate the impact of three PL operational parameters: the fluence per flash, the total fluence and the flash frequency. Fluence per flash appeared to be a key parameter prior to total fluence, thus demonstrating the importance of the effect of peak voltage during PL treatments. The efficiency of PL treatment was assessed on 198 strains distributed amongst fourteen yeast species related to wine environment, and an important variability in PL response was observed. Brettanomyces bruxellensis strains were strongly sensitive to PL, with intraspecific variation. PL was then applied to red wines inoculated with 9 strains of B. bruxellensis, Saccharomyces cerevisiae and Lachancea thermotolerans. Results confirmed interspecific response variability and a higher sensitivity of B. bruxellensis species to PL. Wine treatments with a total fluence of 22.8 J cm-2 resulted in more than 6 log reduction for different B. bruxellensis strains. These results highlight the potential of PL for wine microbial stabilization
Fermentation indigÚne et pied de cuve . Résultats du projet Casdar « Levains Bio »
Article de revue professionnelleDepuis plusieurs annĂ©es, les producteurs de vins biologiques ont tendance Ă utiliser les micro-organismes indigĂšnes pour la rĂ©alisation des fermentations alcooliques (rĂ©sultats de lâenquĂȘte nationale sur les pratiques et les besoins Ćnologiques en bio 2014 ITAB). Les producteurs de vins conventionnels sont Ă©galement intĂ©ressĂ©s par ces itinĂ©raires. La flore indigĂšne est imposĂ©e par la nature, elle varie notamment selon le millĂ©sime et les conditions climatiques. Elle est composĂ©e dâun consortium dâespĂšces et de souches variĂ©es, dâintĂ©rĂȘt technologique incertain et de performances technologiques trĂšs inĂ©gales. Cette pratique peut donc mener Ă des difficultĂ©s de fermentation, avec des risques de fermentation incomplĂšte, de dĂ©viations aromatiques (H2S, phĂ©nols volatils, acĂ©tate dâĂ©thyle) ou des altĂ©rations sur vins (production de SO2 ou dâaciditĂ© volatile).
Dans le cadre du projet Casdar « Levains Bio » de 2012 Ă 2015, des expĂ©rimentations ont Ă©tĂ© conduites dans les quatre rĂ©gions participant au programme (Aquitaine, Bourgogne, Languedoc-Roussillon, Val de Loire), sur la technique dâensemencement par pied de cuveâŻ(PDC). Lâobjectif du projet est dâamĂ©liorer la maĂźtrise de cette pratique et de fournir Ă terme aux professionnels, des protocoles Ă©prouvĂ©s permettant dâutiliser la flore indigĂšne et de sĂ©curiser aussi ses fermentations alcooliques (FA)âŻ.
Les essais sont rĂ©alisĂ©s en collaboration par lâInstitut français de la vigne et du vin (IFV), lâInstitut supĂ©rieur de la vigne et du vin (ISVV) et les Syndicat des vignerons bio des quatre rĂ©gions, lâITAB, lâIFPC, Microflora. Ils sont rĂ©alisĂ©s en vinification en blanc et en vinification en rouge, Ă lâĂ©chelle pilote au chai expĂ©rimental mais Ă©galement, depuis 2014, sur site en condition rĂ©elle chez des viticulteurs et des lycĂ©es viticoles collaborant au projet
Researh on the origin and the side effects of chitosan stabilizing properties in wine
International audienc
Des outils pour fiabiliser les fermentations des vins et cidres biologiques en utilisant les levures et bactéries indigÚnes
Ce numĂ©ro comprend les articles correspondant aux prĂ©sentations du Colloque Casdar 2018.With the development of organic wines and ciders, there is a real tendency to carry out spontaneousfermentations, which involve the development of indigenous yeasts and bacteria. Indeed, thesemicroorganisms are sometimes considered as components of the terroir that participate in the typicity ofwines and ciders. However, no scientific knowledge allows us to assert such a specificity, while the lackof control of these microorganisms can lead to difficulties of fermentation, aromatic deviations oralterations. The project CASDAR Levains Bio relied on a network of laboratories, technical institutes andassociations of organic producers to provide the necessary knowledge and practical solutions forcarrying out indigenous fermentations with a good level of control. It has been shown that there is awide diversity of strains of the yeast Saccharomyces cerevisiae and the lactic acid bacteriumOenococcus oeni, that strains are genetically adapted to certain products, but not to regions orproduction sites. Protocols have been developed to allow for the selection of strains from farms or forthe production of "pieds de cuve". Some of the solutions have been successfully transferred toproducers.Avec le dĂ©veloppement des vins et cidres bio, on observe une vraie tendance Ă la rĂ©alisation defermentations spontanĂ©es, en laissant se dĂ©velopper les levures et bactĂ©ries indigĂšnes. En effet, cesmicroorganismes sont parfois considĂ©rĂ©s comme des Ă©lĂ©ments du terroir qui participent Ă la typicitĂ© desvins et des cidres. Pourtant, aucune connaissance scientifique ne permet dâaffirmer une telle spĂ©cificitĂ©,alors que la non-maĂźtrise de ces microorganismes peut conduire Ă des difficultĂ©s de fermentation, desdĂ©viations aromatiques ou des altĂ©rations. Le projet Casdar Levains Bio sâest appuyĂ© sur un rĂ©seau delaboratoires, instituts techniques et associations de producteurs bio pour apporter les connaissancesnĂ©cessaires et des solutions pratiques pour rĂ©aliser des fermentations indigĂšnes avec un bon niveau demaĂźtrise. Il a Ă©tĂ© montrĂ© quâil existe une grande diversitĂ© de souches de la levure Saccharomycescerevisiae et de la bactĂ©rie lactique Oenococcus oeni, que des souches sont gĂ©nĂ©tiquement adaptĂ©es Ă certains produits, mais pas Ă des rĂ©gions ou Ă des sites de production. Des protocoles ont Ă©tĂ© mis aupoint pour permettre de sĂ©lectionner des souches issues des exploitations ou pour rĂ©aliser des pieds decuve de microorganismes indigĂšnes. Certaines des solutions ont Ă©tĂ© transfĂ©rĂ©es avec succĂšs auprĂšsdes producteurs
Innov. agron.
Avec le dĂ©veloppement des vins et cidres bio, on observe une vraie tendance Ă la rĂ©alisation de fermentations spontanĂ©es, en laissant se dĂ©velopper les levures et bactĂ©ries indigĂšnes. En effet, ces microorganismes sont parfois considĂ©rĂ©s comme des Ă©lĂ©ments du terroir qui participent Ă la typicitĂ© des vins et des cidres. Pourtant, aucune connaissance scientifique ne permet dâaffirmer une telle spĂ©cificitĂ©, alors que la non-maĂźtrise de ces microorganismes peut conduire Ă des difficultĂ©s de fermentation, des dĂ©viations aromatiques ou des altĂ©rations. Le projet Casdar Levains Bio sâest appuyĂ© sur un rĂ©seau de laboratoires, instituts techniques et associations de producteurs bio pour apporter les connaissances nĂ©cessaires et des solutions pratiques pour rĂ©aliser des fermentations indigĂšnes avec un bon niveau de maĂźtrise. Il a Ă©tĂ© montrĂ© quâil existe une grande diversitĂ© de souches de la levure Saccharomyces cerevisiae et de la bactĂ©rie lactique Oenococcus oeni, que des souches sont gĂ©nĂ©tiquement adaptĂ©es Ă certains produits, mais pas Ă des rĂ©gions ou Ă des sites de production. Des protocoles ont Ă©tĂ© mis au point pour permettre de sĂ©lectionner des souches issues des exploitations ou pour rĂ©aliser des pieds de cuve de microorganismes indigĂšnes. Certaines des solutions ont Ă©tĂ© transfĂ©rĂ©es avec succĂšs auprĂšs des producteurs. | With the development of organic wines and ciders, there is a real tendency to carry out spontaneous fermentations, which involve the development of indigenous yeasts and bacteria. Indeed, these microorganisms are sometimes considered as components of the terroir that participate in the typicity of wines and ciders. However, no scientific knowledge allows us to assert such a specificity, while the lack[br/] of control of these microorganisms can lead to difficulties of fermentation, aromatic deviations or alterations. The project CASDAR Levains Bio relied on a network of laboratories, technical institutes and associations of organic producers to provide the necessary knowledge and practical solutions for carrying out indigenous fermentations with a good level of control. It has been shown that there is a wide diversity of strains of the yeast Saccharomyces cerevisiae and the lactic acid bacterium Oenococcus oeni, that strains are genetically adapted to certain products, but not to regions or production sites. Protocols have been developed to allow for the selection of strains from farms or for the production of "pieds de cuve". Some of the solutions have been successfully transferred to producers
PLoS One
Brettanomyces bruxellensis is the main wine spoiler yeast all over the world, yet the structure of the populations associated with winemaking remains elusive. In this work, we considered 1411 wine isolates from 21 countries that were genotyped using twelve microsatellite markers. We confirmed that B. bruxellensis isolates from wine environments show high genetic diversity, with 58 and 42% of putative triploid and diploid individuals respectively distributed in 5 main genetic groups. The distribution in the genetic groups varied greatly depending on the country and/or the wine-producing region. However, the two possible triploid wine groups showing sulfite resistance/tolerance were identified in almost all regions/countries. Genetically identical isolates were also identified. The analysis of these clone groups revealed that a given genotype could be isolated repeatedly in the same winery over decades, demonstrating unsuspected persistence ability. Besides cellar residency, a great geographic dispersal was also evidenced, with some genotypes isolated in wines from different continents. Finally, the study of old isolates and/or isolates from old vintages revealed that only the diploid groups were identified prior 1990 vintages. The putative triploid groups were identified in subsequent vintages, and their proportion has increased steadily these last decades, suggesting adaptation to winemaking practices such as sulfite use. A possible evolutionary scenario explaining these results is discussed