17 research outputs found
Etude de la diversitĂ© des souches dâOenococcus oeni responsables de la fermentation malolactique des vins dans diffĂ©rentes rĂ©gions vitivinicoles
Oenococcus oeni is the main species of lactic acid bacteria of oenological interest, it performs most of malolactic fermentation. O. oeni strains have often been studied to select malolactic starters. These strains have various genetic and phenotypic characteristics. However, the use of different typing methods failed so far to obtain a complete picture of the enological diversity of this species. The growing interest of winegrowers to better control the spontaneous requires a better knowledge of this diversity.The population of indigenous O. oeni strains present during MLF in different regions has been studied in an attempt to obtain a more complete picture of the diversity of the species and to know whether it would be appropriate to select strains of regions or wineries. The analysis of a large number of wines showed the presence of strains specific to wineproducing areas, different kind of wines, and wineries. SNP Genotyping allowed us to classify these strains in the already known genetic groups and confirmed the existence of specific groups to a specific kind of product. Some of these strains belonging to the same specific genetic groups showed similar behavior and technological properties. In addition to the diversity analysis, trials of production of strains and use of lees to ameliorate the MLF have been done to improve the achievement of spontaneous MLF. Taken together, these studies emphasize the high genetic diversity of the species O. oeni, the study of specific strains of type of wine could help understand the adaptation of this species to this environment.Oenococcus oeni est la principale espĂšce de bactĂ©rie lactique dâintĂ©rĂȘt oenologique, elle rĂ©alise la plupart des fermentations malolactiques. Les souches dâO. oeni ont souvent Ă©tĂ© Ă©tudiĂ©es dans le but de sĂ©lectionner des levains malolactiques. Ces souches possĂšdent des caractĂ©ristiques gĂ©nĂ©tiques, et phĂ©notypiques variĂ©es. NĂ©anmoins, lâutilisation de diffĂ©rentes mĂ©thodes de typage nâa pas permis Ă ce jour dâobtenir une image exhaustive de la diversitĂ© oenologique de cette espĂšce. LâintĂ©rĂȘt grandissant des viticulteurs pour mieux maitriser les FML spontanĂ©es nĂ©cessite de mieux connaitre cette diversitĂ©.La population de souches indigĂšnes dâO. oeni prĂ©sentes dans les FML de diffĂ©rentes rĂ©gions a Ă©tĂ© Ă©tudiĂ©e, pour tenter dâobtenir une image plus complĂšte de la diversitĂ© de cette espĂšce et savoir sâil serait pertinent de sĂ©lectionner des souches de rĂ©gions ou dâexploitations. Lâanalyse dâun trĂšs grand nombre de vins a mis en Ă©vidence la prĂ©sence de souches spĂ©cifiques aux rĂ©gions, appellations, produits et exploitations Ă©tudiĂ©es. Un gĂ©notypage Ă lâaide de SNP a permis de les classer dans les groupes gĂ©nĂ©tiques dĂ©jĂ connu et a confirmĂ© lâexistence de groupes spĂ©cifiques Ă un type de produit. Certaines de ces groupes rassemblent des souches prĂ©sentant des comportements phĂ©notypiques et des capacitĂ©s fermentaires similaires. En complĂ©ment de lâanalyse de diversitĂ©, des essais ont Ă©tĂ© menĂ©s pour proposer des protocoles de production de souches et dâutilisation de lies pour amĂ©liorer la rĂ©alisation des FML spontanĂ©es. Lâensemble de ces travaux soulignent la grande diversitĂ© gĂ©nĂ©tique de lâespĂšce O. oeni, lâĂ©tude des souches spĂ©cifiques de type de vin pourrait aider Ă comprendre son adaptation Ă cet environnement
Isolation, selection, and characterization of highly ethanol-tolerant strains of Oenococcus oeni from south Catalonia
Twenty-one strains of Oenococcus oeni were isolated during the malolactic fermentation of wines from south Catalonia. Due to their high ethanol tolerance (14 %, or more), these strains may serve as promising starters. The strains were screened by assays in a wine-like medium and by their co-inoculation in wine, resulting in the selection of well-performing strains, subsequently shown not to produce the main biogenic amines and lacking the genes involved in their synthesis. The genetic diversity of the isolates was studied by multilocus sequence typing (MLST), in which seven housekeeping genes were sequenced. Although the concatenated allelic profi le of some strains was the same, the profi les obtained by random amplifi cation of polymorphic DNA together with the variable number of tandem repeats at several loci showed that none of the strains were identical. A phylogenetic tree was constructed based on MLST with the seven genes and clearly showed two phylogroups, in accordance with previous studies. The best-performing strains occurred in members of both subgroups, suggesting that the grouping of housekeeping genes is not directly related to adaptation and ethanol tolerance. [Int Microbiol 2013; 16(2):113-123]Keywords: Oenococcus oeni; malolactic fermentation; wine production; multilocus sequence typing (MLST);strain selectio
Selection and characterization of autochthonous strains of Oenococcus oeni for vinification in Priorat (Catalonia, Spain)
The use of autochthonous strains of Oenococcus oeni for inducing malolactic fermentation (MLF) in wines is increasing because they are well adapted to the conditions of a specific area. The main aim of this work was to select O. oeni strains from Priorat (Catalonia, Spain) wines that would be able to carry out the MLF while maintaining the characteristics of the wine. Forty-five autochthonous strains were selected based on their degradation of L-malic acid, resistance to low pH and high ethanol, and the absence of biogenic amine genes. The three strains with the best characteristics were inoculated and MLF was carried out successfully with the final wines showing good characteristics. One of the inoculated O. oeni strains would be a good candidate to study as possible starter culture. It shows that autochthonous O. oeni strains, once selected, have the potential to be used as an inoculum for wines.Multi-strain indigenous Yeast and Bacterial starters for âWild-fermentâ Wine productio
Appl Environ Microbiol
Understanding the mechanisms behind the typicity of regional wines inevitably brings attention to microorganisms associated with their production. Oenococcus oeni is the main bacterial species involved in wine and cider making. It develops after the yeast-driven alcoholic fermentation and performs the malolactic fermentation, which improves the taste and aromatic complexity of most wines. Here, we have evaluated the diversity and specificity of O. oeni strains in six regions. A total of 235 wines and ciders were collected during spontaneous malolactic fermentations and used to isolate 3,212 bacterial colonies. They were typed by multilocus variable analysis, which disclosed a total of 514 O. oeni strains. Their phylogenetic relationships were evaluated by a second typing method based on single nucleotide polymorphism (SNP) analysis. Taken together, the results indicate that each region holds a high diversity of strains that constitute a unique population. However, strains present in each region belong to diverse phylogenetic groups, and the same groups can be detected in different regions, indicating that strains are not genetically adapted to regions. In contrast, greater strain identity was seen for cider, white wine, or red wine of Burgundy, suggesting that genetic adaptation to these products occurred. This study reports the isolation, genotyping, and geographic distribution analysis of the largest collection of O. oeni strains performed to date. It reveals that there is very high diversity of strains in each region, the majority of them being detected in a single region. The study also reports the development of an SNP genotyping method that is useful for analyzing the distribution of O. oeni phylogroups. The results show that strains are not genetically adapted to regions but to specific types of wines. They reveal new phylogroups of strains, particularly two phylogroups associated with white wines and red wines of Burgundy. Taken together, the results shed light on the diversity and specificity of wild strains of O. oeni, which is crucial for understanding their real contribution to the unique properties of wines.Multi-strain indigenous Yeast and Bacterial starters for âWild-fermentâ Wine productio
Two different Oenococcus oeni lineages are associated to either red or white wines in Burgundy: genomics and metabolomics insights
Oenococcus oeni is the bacterium most often associated with spontaneous malolactic fermentation (MLF) of wine. During MLF, malic acid is transformed into lactic acid and several metabolites are modified, modulating wineâs total acidity and improving its sensory properties. Previous works have suggested that certain genetic groups of O. oeni strains are associated to different kinds of products. In the present study we have spotted two groups of strains isolated mainly from Burgundy wines, one associated to red wines and the other to white wines. Sequencing 14 genomes of red and white wine strains revealed that they share a common ancestor that probably colonised two different substrates âred and white wine-associated environmentsâ, diverging over time and disseminating to various regions. Their capacity to perform MLF and modify the volatile profile of wine was determined by fermenting a chardonnay wine and analysing its volatile fraction with a non-targeted metabolomics approach by GC-MS. The strains had a different impact on the volatile composition depending on their group of origin. These results show for the first time a correspondence between the product of origin of the strains and the volatile profile of the wines they produce. Furthermore, the genetic features that might be implied in these different phenotypes are examined
Study of the diversity of Oenococcus oeni strains responsible for malolactic fermentation of wine in different winemaking regions
Oenococcus oeni est la principale espĂšce de bactĂ©rie lactique dâintĂ©rĂȘt oenologique, elle rĂ©alise la plupart des fermentations malolactiques. Les souches dâO. oeni ont souvent Ă©tĂ© Ă©tudiĂ©es dans le but de sĂ©lectionner des levains malolactiques. Ces souches possĂšdent des caractĂ©ristiques gĂ©nĂ©tiques, et phĂ©notypiques variĂ©es. NĂ©anmoins, lâutilisation de diffĂ©rentes mĂ©thodes de typage nâa pas permis Ă ce jour dâobtenir une image exhaustive de la diversitĂ© oenologique de cette espĂšce. LâintĂ©rĂȘt grandissant des viticulteurs pour mieux maitriser les FML spontanĂ©es nĂ©cessite de mieux connaitre cette diversitĂ©.La population de souches indigĂšnes dâO. oeni prĂ©sentes dans les FML de diffĂ©rentes rĂ©gions a Ă©tĂ© Ă©tudiĂ©e, pour tenter dâobtenir une image plus complĂšte de la diversitĂ© de cette espĂšce et savoir sâil serait pertinent de sĂ©lectionner des souches de rĂ©gions ou dâexploitations. Lâanalyse dâun trĂšs grand nombre de vins a mis en Ă©vidence la prĂ©sence de souches spĂ©cifiques aux rĂ©gions, appellations, produits et exploitations Ă©tudiĂ©es. Un gĂ©notypage Ă lâaide de SNP a permis de les classer dans les groupes gĂ©nĂ©tiques dĂ©jĂ connu et a confirmĂ© lâexistence de groupes spĂ©cifiques Ă un type de produit. Certaines de ces groupes rassemblent des souches prĂ©sentant des comportements phĂ©notypiques et des capacitĂ©s fermentaires similaires. En complĂ©ment de lâanalyse de diversitĂ©, des essais ont Ă©tĂ© menĂ©s pour proposer des protocoles de production de souches et dâutilisation de lies pour amĂ©liorer la rĂ©alisation des FML spontanĂ©es. Lâensemble de ces travaux soulignent la grande diversitĂ© gĂ©nĂ©tique de lâespĂšce O. oeni, lâĂ©tude des souches spĂ©cifiques de type de vin pourrait aider Ă comprendre son adaptation Ă cet environnement.Oenococcus oeni is the main species of lactic acid bacteria of oenological interest, it performs most of malolactic fermentation. O. oeni strains have often been studied to select malolactic starters. These strains have various genetic and phenotypic characteristics. However, the use of different typing methods failed so far to obtain a complete picture of the enological diversity of this species. The growing interest of winegrowers to better control the spontaneous requires a better knowledge of this diversity.The population of indigenous O. oeni strains present during MLF in different regions has been studied in an attempt to obtain a more complete picture of the diversity of the species and to know whether it would be appropriate to select strains of regions or wineries. The analysis of a large number of wines showed the presence of strains specific to wineproducing areas, different kind of wines, and wineries. SNP Genotyping allowed us to classify these strains in the already known genetic groups and confirmed the existence of specific groups to a specific kind of product. Some of these strains belonging to the same specific genetic groups showed similar behavior and technological properties. In addition to the diversity analysis, trials of production of strains and use of lees to ameliorate the MLF have been done to improve the achievement of spontaneous MLF. Taken together, these studies emphasize the high genetic diversity of the species O. oeni, the study of specific strains of type of wine could help understand the adaptation of this species to this environment
Le Challenge ROSE : évaluation itérative d'approches de recherche parallÚles pour le désherbage intra-rang
National audienceEn 2017, les ministĂšres chargĂ©s de l'agriculture et de la transition Ă©cologique ont lancĂ©, en partenariat avec le ministĂšre chargĂ© de la recherche et l'Agence Nationale de la Recherche (ANR), un appel Ă projets « Challenge ROSE ». Il s'agit de susciter la mise au point de solutions technologiques innovantes permettant de contribuer Ă atteindre les objectifs du plan Ecophyto II : rĂ©duire l'utilisation des produits phytopharmaceutiques, garantir une meilleure maĂźtrise de l'ensemble des risques et diminuer la dĂ©pendance de l'agriculture Ă ces produits. Les Ă©quipes de recherche des projets retenus vont se focaliser sur le dĂ©sherbage de l'intra-rang (espacement entre plants sur une mĂȘme rangĂ©e) en cultures lĂ©gumiĂšres de plein champ et en grandes cultures Ă fort Ă©cartement. L'ensemble de la chaĂźne d'intervention sera pris en compte (observation et dĂ©tection des cultures et des mauvaises herbes, interprĂ©tation, action de dĂ©sherbage) grĂące Ă des avancĂ©es scientifiques dans plusieurs domaines : les capteurs, la modĂ©lisation, la robotique et leur combinaison. Les Ă©quipes de recherche disposeront d'une parcelle de l'AgroTechnoPĂŽle sur le site de l'Irstea Ă Montoldre dans l'Allier. Durant quatre ans, ces Ă©quipes vont se confronter chaque annĂ©e Ă des Ă©preuves rĂ©elles de terrain. L'efficacitĂ© du dĂ©sherbage, dans le respect des cultures en place, sera l'objet des campagnes d'Ă©valuation annuelles menĂ©es par le LNE et Irstea, avec la participation de VetAgro Sup
La fermentation malolactique dans les vins de base de cognac : Une étape peu suivie mais trÚs fréquente
Article de revue professionnelleLes donnĂ©es sur la fermentation malolactique (FML) des vins de base de cognac (VDB) sont aujourdâhui encore trĂšs fragmentaires et rares. Son effet sur la qualitĂ© des eaux-de-vie est flou. Le seul fait bien Ă©tabli est la diminution de la teneur en Ă©thanal. On ignore sa frĂ©quence, car les vins ne sont pas analysĂ©s pour la contrĂŽler ; mais gĂ©nĂ©ralement on admet quâelle est inhabituelle. Pourtant elle peut se dĂ©rouler rapidement aprĂšs la fermentation alcoolique, ou jamais. Dans ce travail, les populations de levures et de bactĂ©ries indigĂšnes ont Ă©tĂ© Ă©tudiĂ©es depuis le dĂ©but de la vinification jusquâĂ la distillation du VDB. Les dynamiques sont diffĂ©rentes selon les chais et les pratiques mises en Ćuvre pour les fermentations alcooliques. Le fait marquant et inattendu est que la FML sâest achevĂ©e dans la majoritĂ© des cas, malgrĂ© les conditions trĂšs variables des chais. Par ailleurs, cette Ă©tude fournit des donnĂ©es sur les cinĂ©tiques fermentaires, sur les espĂšces microbiennes (levures et bactĂ©ries). Des souches dâO. oeni ont Ă©tĂ© typĂ©es. Ces rĂ©sultats dĂ©montrent lâintĂ©rĂȘt dâune Ă©tude approfondie de la FML et de son impact sur le cognac
Le Challenge ROSE (2018â2021) : Ă©valuation itĂ©rative dâapproches de recherche parallĂšles pour le dĂ©sherbage intra-rang.
En 2017, les ministĂšres chargĂ©s de lâagriculture et de la transition Ă©cologique ont lancĂ©, en partenariat
avec le ministĂšre chargĂ© de la recherche et lâAgence Nationale de la Recherche (ANR), un appel Ă
projets «Challenge ROSE». Il sâagit de susciter la mise au point de solutions technologiques innovantes
permettant de contribuer Ă atteindre les objectifs du plan Ecophyto II : rĂ©duire lâutilisation des produits
phytopharmaceutiques, garantir une meilleure maĂźtrise de lâensemble des risques et diminuer la
dĂ©pendance de lâagriculture Ă ces produits.
Les projets retenus sont focalisĂ©s sur le dĂ©sherbage de lâintra-rang (espacement entre plants sur une
mĂȘme rangĂ©e) en cultures lĂ©gumiĂšres de plein champ et en grandes cultures Ă fort Ă©cartement.
Lâensemble de la chaĂźne dâintervention est pris en compte (observation et dĂ©tection des cultures et des
mauvaises herbes, interprétation, action de désherbage) grùce à des avancées scientifiques dans
plusieurs domaines : les capteurs, la modélisation, la robotique et leur combinaison.
Les Ă©quipes participantes disposent dâune parcelle de lâAgroTechnoPĂŽle sur le site de lâIrstea Ă
Montoldre dans lâAllier. Durant quatre ans, ces Ă©quipes vont se confronter chaque annĂ©e Ă des
Ă©preuves rĂ©elles de terrain. LâefficacitĂ© du dĂ©sherbage, dans le respect des cultures en place, sera
lâobjet des campagnes dâĂ©valuation annuelles menĂ©es par le LNE et Irstea, avec la participation de
VetAgro Sup.In 2017, the Ministries of agriculture and ecological transition launched, in partnership with the Ministry
of Research and the French National Research Agency (ANR), the call for research proposals âROSE
Challengeâ. The aim is to encourage the development of innovative technological solutions to help
achieve the objectives of the Ecophyto II plan: reducing the use of plant protection products at least by
half, ensuring better control of all risks and reducing agricultureâs dependence on chemicals.
The research teams of the selected projects will focus on intra-row weeding (intra row: spacing between
plants in the same row) in field vegetable crops and wide-spaced field crops (i.e. maize, sunflower).[br/]
The entire chain of action will be taken into account (observation and detection of crops and weeds,
interpretation, weeding) thanks to scientific advances in several fields: sensors, modelling, robotics and
their combination.
The research teams will have a plot of land belonging to the AgroTechnoPĂŽle at the Irstea site in
Montoldre, France. For 4 years, these teams will be confronted with real field events. The effectiveness
of weeding, while respecting existing crops, will be the subject of annual evaluation campaigns
conducted by the LNE and Irstea, with the participation of VetAgro Sup
Biogeography of Oenococcus oeni reveals distinctive but nonspecific populations in wine-producing regions
Understanding the mechanisms behind the typicity of regional wines inevitably brings attention to microorganisms associated with their production. Oenococcus oeni is the main bacterial species involved in wine and cider making. It develops after the yeast-driven alcoholic fermentation and performs the malolactic fermentation, which improves the taste and aromatic complexity of most wines. Here, we have evaluated the diversity and specificity of O. oeni strains in six regions. A total of 235 wines and ciders were collected during spontaneous malolactic fermentations and used to isolate 3,212 bacterial colonies. They were typed by multilocus variable analysis, which disclosed a total of 514 O. oeni strains. Their phylogenetic relationships were evaluated by a second typing method based on single nucleotide polymorphism (SNP) analysis. Taken together, the results indicate that each region holds a high diversity of strains that constitute a unique population. However, strains present in each region belong to diverse phylogenetic groups, and the same groups can be detected in different regions, indicating that strains are not genetically adapted to regions. In contrast, greater strain identity was seen for cider, white wine, or red wine of Burgundy, suggesting that genetic adaptation to these products occurred.IMPORTANCE This study reports the isolation, genotyping, and geographic distribution analysis of the largest collection of O. oeni strains performed to date. It reveals that there is very high diversity of strains in each region, the majority of them being detected in a single region. The study also reports the development of an SNP genotyping method that is useful for analyzing the distribution of O. oeni phylogroups. The results show that strains are not genetically adapted to regions but to specific types of wines. They reveal new phylogroups of strains, particularly two phylogroups associated with white wines and red wines of Burgundy. Taken together, the results shed light on the diversity and specificity of wild strains of O. oeni, which is crucial for understanding their real contribution to the unique properties of wines