Teses / dissertações sobre o tema "Vie végétale"
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Kazakou, Elena. "Vie, mort et décomposition des feuilles d'espèces de succession secondaire méditerranéenne : vers une intégration de la gestion des éléments minéraux par les végétaux". Montpellier 2, 2006. http://www.theses.fr/2006MON20041.
Texto completo da fonteThe main aim of this work is to determine the links between the processes occurring before, during and after leaf senescence. Two experiments were set up: one in a gradient of an old-field succession and a second one in a common garden experiment, where 18 species characterising the three stages of this succession were transplanted in two fertilisation levels. Our results demonstrate that leaf life span and nutrient resorption efficiency are two important and alternative strategies of nutrient conservation. Litter decomposability is successfully predicted by some traits of green leaves, especially those describing leaf robustness (leaf dry matter content, leaf tensile strength and leaf resistance to fracture). The leaf economic spectrum describing nutrient use in plants was found across species differing in successional stage. Species from early succession with high resource acquisition rates are replaced during succession by species which tend to conserve resources efficiently, the latter tending to produce leaves with low decomposition rates. Finally, in order to scale up from species to the ecosystem functioning, we propose to use leaf dry matter content as a functional marker of litter decomposability
Breton, Audrey. "Potentialité de la biomasse végétale pour le traitement des eaux usées domestiques : développement d’un procédé de biofiltration pour l’assainissement non collectif". Thesis, Toulouse, INPT, 2013. http://www.theses.fr/2013INPT0082.
Texto completo da fonteIn France, 13 million people are concerned by on-site wastewater treatment (OSWWT). An OSWWT system consists of pretreatment, usually a septic tank, followed by a treatment system. Recent regulatory developments open up a range of possibilities as to possible treatment systems for wastewater treatment. The objective of this thesis is to develop a system of wastewater treatment based on plant biomass from waste of agriculture. Analytical monitoring of six individual houses allowed the study of the characteristics of the wastewater before and after their entry into the pretreatment system. Waters are characterized by a wide variability from one family to another and from the same house. The organic load per person is treating an average of 60 gDBO5.j-1 for a volume of water discharged 90 L.j-1, that to say effluent two times more concentrated than indicated by the regulations. The design and monitoring of a pilot scale laboratory were used to evaluate the potential of several plant biomass for the treatment of pretreated wastewater. They are compared to a reference medium with proven effectiveness in water treatment. The study of treatment performance for two different volume loads of different backgrounds was performed during forty weeks. This study resulted in the development and implementation of a pilot in situ for single house. The approach of life cycle analysis has been applied to in situ pilot in order to optimize the process in place. In addition, LCA has to make a comparison with different existing OSWWT
Chateau, Sophie. "Les marqueurs de la compétence cellulaire à la transformation génétique via agrobacterium tumefaciens, chez les plantes modèles petunia hybrida L. Et arabidopsis thaliana L". Amiens, 2000. http://www.theses.fr/2000AMIE0105.
Texto completo da fonteFaivre, Nicolas. "Quelle pyrodiversité pour quelle biodiversité ? Une étude comparative multi-échelle de deux écosystèmes méditerranéens". Thesis, Aix-Marseille 3, 2011. http://www.theses.fr/2011AIX30013.
Texto completo da fonteAim and Background. Fire is an integral component of Mediterranean type ecosystems and other fire-prone systems worldwide but the perception of fire as an ecological disaster remains a widely-held view among human societies. Understanding whether and to what extent fire is beneficial or detrimental to biodiversity is a current research priority for conservation management in fire-prone systems. My research has attempted to quantify the multi-scale effects of fire on various facets of vegetation diversity, including landscape diversity, taxonomic diversity and functional diversity from a landscape ecology perspective. We used two contrasted Mediterranean study cases i.e., south-eastern France and south-western Australia in order to distinguish from their differences common ecological patterns.Methods. Fires and their effects on vegetation are normally studied as single and localized events. Here, we considered landscape-scale fire mosaics resulting from the compilation of fire events that occurred among time and space in a given landscape. The diversity of those fire mosaics has been quantified and permitted to define a new parameter i.e., pyrodiversity. This research proposes a conceptual and practical methodology for the objective characterization of pyrodiversity based on the comparison of two Mediterranean environments: south-west of Western Australia and southern France. Fire patterns were analyzed retrospectively over a 50-year period while vegetation, habitats and species diversity were quantified at the landscape scale using a monitoring protocol developed within the EBONE EU-project. Using the same geographical scale for fire and vegetation patterns permitted to cross the information on biodiversity and pyrodiversity. The relationship between pyrodiversity and biodiversity was examined at the community level (i.e., habitat) and landscape level (mosaic of habitats) with considering successively habitat diversity, taxonomic diversity and functional diversity.ResultsThis study provides evidence that high pyrodiversity (i.e., spatio-temporal diversity of fire patterns) is associated to various successional trajectories of vegetation and thereby maximizes the diversity of habitats at landscape scale. The results indicate that fire significantly contributes with environmental factors and land management to determine the composition of habitats across a landscape and spatial heterogeneity of landscape mosaics. Whether considering the effects of a single fire event on plant species or on plant functional traits, I found that plant diversity varies with fire frequency according to the intermediate disturbance hypothesis at the habitat level. At the landscape level, the pyrodiversity-biodiversity relationship verified the heterogeneous disturbance hypothesis i.e., maxima of alpha and beta diversity are associated to fire mosaics of high spatiotemporal heterogeneity. At the regional scale, pyrodiversity enhances habitat diversity (gamma diversity) within the landscape until a certain threshold. The two studies areas display contrasting profiles of pyrodiversity due to their different fire management strategies but also exhibit taxonomically unrelated floras. Hence, the two Mediterranean biomes were characterized by different ecosystem resilience and resistance to fire. Despite these differences, the two Mediterranean biomes show convergence trends in their ecological response to the gradient of pyrodiversity.Conclusion. This study tackled the Pyrodiversity-Biodiversity paradigm and demonstrated that Mediterranean-type ecosystems need pyrodiversity to maintain the variety of habitats and species at both habitat and landscape levels. Fire effects on vegetation cannot be interpreted directly from a local perspective with considering a single fire event
Hoare, Catherine. "Les Végétaux dans la vie du peuple WE (Côte d'Ivoire)". Paris 6, 1988. http://www.theses.fr/1988PA066091.
Texto completo da fonteCapel, Eliott. "La grande révolution terrestre du Silurien-Dévonien : diversité et évolution des premières plantes terrestres". Electronic Thesis or Diss., Université de Lille (2022-....), 2022. https://pepite-depot.univ-lille.fr/ToutIDP/EDSMRE/2022/2022ULILR059.pdf.
Texto completo da fontePlants underwent an extensive Silurian-Devonian diversification during their progressive colonization of terrestrial surfaces (440-360 Ma). Nonetheless, the tempo and mode of this radiation remains controversial, and drivers of diversity have yet to be clearly identified. This thesis, through a series of newly-compiled datasets of plant macrofossils, and via a wide array of quantitative methods, characterizes temporal and spatial dynamics. It further evaluates the biases that may alter our perception of this landmark event. Firstly, a four-factor model was found adequate to describe the underlying structure of early vegetation dynamics. The pattern suggests ecological shifts during transitions phases, further corroborated through an in-depth characterization of global plant diversity patterns. Nevertheless, the general pattern of Silurian-Devonian plant diversity was found to heavily depend on sampling effort, although several signals of diversification and extinction seemed to be dissociated from it, implying real underlying biological signals. A subsequent continental-scale study further demonstrated that, in addition to sampling heterogeneity, geological incompleteness remained an important element in driving apparent early land plant diversity patterns. This bias is not easily corrected even with the most advanced sampling-standardization methods. Furthermore, paleogeographical discrepancies were assessed to uncover a possible spatial component into early land plant radiation. This led to the discovery of a climatologically-driven plant distribution and dispersion, further enhanced during colder periods. Lastly, this thesis includes a review of an Early Devonian plant fossil assemblage from northern France, providing taxonomically up to date and well-dated occurrences to integrate in future studies
Boulanger, Vincent. "Pression d'herbivorie et dynamique des communautés végétales : Influence à court et moyen termes des populations de cervidés sur la diversité des communautés végétales en forêt". Phd thesis, Nancy 1, 2010. http://tel.archives-ouvertes.fr/tel-00518080.
Texto completo da fonteDelalandre, Léo. "Relations traits-environnement chez les végétaux : du cycle de vie des organismes au cycle de vie des données". Electronic Thesis or Diss., Université de Montpellier (2022-....), 2024. http://www.theses.fr/2024UMONG001.
Texto completo da fonteComparative ecology has highlighted recurring associations between plant functional traits and their environment. These relationships may vary depending on the level of organization considered – within species, between species, and among groups of species – but this dependency remains poorly studied. A fundamental distinction in life history theories is made between annual species (completing their life cycle in one year) and perennial species (life cycle over more than one year, usually with multiple reproductive events). Annual and perennial herbaceous plants differ in their functioning (growth rate, investment in seed production, allocation to roots, etc.). However, despite their frequent coexistence, few studies have considered potential differences in trait-environment relationships between these two groups. The objective of this thesis is to understand the specific variations in the traits of annual plants depending on resource availability, based on in situ measurements and in a common garden setting.We studied herbaceous communities in the Grands Causses, where annuals and perennials coexist in two contrasting environmental conditions: i) fertilization and high disturbance, and ii) poor soil and less intense disturbance. We show that variations in traits related to growth rate and leaf tissue density are lower in annuals than in perennials. This is explained by (a) a higher species turnover in perennials, and (b) the presence of species with larger differences in trait values between environments in perennials. Intraspecific variations are identical between the two groups of species. Measurements made during this first part were used to complete a trait database under development. On this occasion, I contributed to the structuring of this database through data management work, aiming to propose modalities for sharing functional trait data and associated environmental variables; a synthesis of this work is proposed.Secondly, we analyzed intraspecific variability in annuals from these communities, in order to test its origin (genetic or plastic), to identify the most variable traits in response to fertilization, and to compare this variability between species. Thirty populations were grown in a common garden, with low or high fertilization. The results indicate that i) the observed trait variations in situ are likely of plastic origin; ii) plasticity is low in morphological leaf and root traits but high in biomass allocation and nitrogen content; iii) species preferring nutrient-rich environments are more plastic in their nitrogen content.Finally, a literature review was undertaken to determine which traits are determinant for annual and perennial herbaceous plants, reasoning on demographic components (reproduction, growth, survival), the importance of which differs according to the life cycle. We propose an opinion article aiming to better integrate life cycle and commonly measured morpho-physio-phenological traits.This thesis proposes a study of the relationships between functional traits and the environment at different levels of organization: between life cycles, between species, and within species. It highlights that trait-environment relationships can vary between these levels, fitting into a renewed interest in context dependency in comparative ecology
Quinte, Jana. "Cycle de la vie des plantes à fleurs - lebenszyklus der blütenpflanzen : étude comparative des conceptions d'élèves en Alsace et au Baden-Württemberg". Thesis, Strasbourg, 2016. http://www.theses.fr/2016STRAG013/document.
Texto completo da fonteThis research aims to investigate students’ conceptions about the life cycle of flowering plants in both Alsace and Baden-Württemberg, in primary and secondary schools, to detect potential factors influencing student’s conceptions and to identify main learning obstacles. Three elements structured this PhD-thesis: 1) an exploratory investigation with the help of interviews (n=49) ; 2) a context analysis of references in natural sciences and in the socio-cultural domain, of “curricula to teach” through school programmes and manuals, and of “taught curricula” ; 3) a main investigation using questionnaires (n=1388). The instruments included questions to key concepts (seed, flower, fruit) and processes (pollination, fecundation, fructification, formation of seeds, dissemination), which characterize the life cycle of flowering plants. Students were especially asked to order different development stages of plants and to explain their ordering. Different mental models could be derived from the results. Moreover, results were related to those of the context analysis. Conceptualizations of the life cycle of plants depend, amongst others, on those of the sexual reproduction and thus the type of plant (flower, fruit tree). Cultural differences were also identified
Schneider, Rémi. "Contribution à la connaissance de l'arôme et du potentiel aromatique du Melon B. (Vitis vinifera L. ) et des vins de Muscadet". Montpellier 2, 2001. http://www.theses.fr/2001MON20156.
Texto completo da fontePelosse, Perrine. "Rôle des compromis évolutifs dans la spécialisation et la coexistence d'espèces compétitrices : développements théoriques et expérimentaux chez les insectes parasitoïdes". Phd thesis, Université Claude Bernard - Lyon I, 2008. http://tel.archives-ouvertes.fr/tel-00369569.
Texto completo da fonteBourdy, Geneviève. "Ethnopharmacologie et vie sexuelle à Vanuatu. Etude pharmacochimique de Dysoxylum gaudichaudianum (Juss. ) Miq". Montpellier 1, 1989. http://www.theses.fr/1989MON13501.
Texto completo da fonteRenoux, Eddy. "L'impact des genres de vie littoraux sur les couverts végétaux du Nord-Ouest de Madagascar". Phd thesis, Université de Nantes, 2011. http://tel.archives-ouvertes.fr/tel-00584931.
Texto completo da fonteWalling, Emilie. "La biosynthèse d'exopolysaccharides par les bactéries lactiques du vin : approche génétique, enzymatique et physiologique de la production de glucane par Pediococcus damnosus". Bordeaux 2, 2003. http://www.theses.fr/2003BOR21014.
Texto completo da fontePediococcus damnosus is a wine lactic acid bacteria. Some strains spoil the wine by thickening its texture. This is due to microbial glucan production. The genetics of glucan biosynthesis was studied. A 5,5 kb plasmid is involved. It carries three open reading frames encoding the functions of replication (Rep), mobilisation (Mob), and glucosyltransfer (Dps). Dps is a good candidate as a glucan synthase. Moreover,, gene dps is present in all the ropy P. Damnosus strains isolated from altered wine and cider, but also in a ropy Oenococcus oeni strain; The physiological parameters for glucan production are described, as well as a PCR detection for contaminating agents. A method for the direct purification of DNA from wine microorganisms is established
Dusza, Yann. "Toitures végétalisées et services écosystémiques : favoriser la multifonctionnalité via les interactions sols-plantes et la diversité végétale". Thesis, Paris 6, 2017. http://www.theses.fr/2017PA066033/document.
Texto completo da fonteGreen roofs are urban constructed ecosystems, associated with multiple ecosystem services, such as urban heat island and stormwater runoff mitigation or support for biodiversity. Enhancing the quality and quantity of expected ecosystem services requires to understand how interactions between substrate composition, substrate depth and plant community affect multiple ecosystem functions. However, such interactions have never been studied on green roofs. Using experimental approaches under controlled and real conditions on a Parisian rooftop, we focused on the influence of soil-plant interactions on key ecosystem functions related to carbon, nitrogen and water cycles as well as pollination. We highlighted that interactions between substrate type, substrate depth, plant species and plant diversity affect (1) the level of ecosystem functions and (2) interactions between functions. We found that the choice of green roof components could lead to trade-offs between ecosystem services. We propose general guidelines for the conception and management of multifunctional green roofs
Lyon, Florent. "Amélioration de la durée de vie d'essences de bois peu durables à l'aide d'un traitement combiné boates/huiles végétales". Phd thesis, Université Montpellier II - Sciences et Techniques du Languedoc, 2007. http://tel.archives-ouvertes.fr/tel-00567069.
Texto completo da fonteLyon, Florent. "Amélioration de la durée de vie d'essences de bois peu durables à l'aide d'un traitement combiné borates/huiles végétales". Montpellier 2, 2007. http://www.theses.fr/2007MON20105.
Texto completo da fonteDo, Quoc Tuan. "Pharmacognosie inverse : des molécules naturelles aux plantes via Selnergy, un outil original de criblage biologique virtuel". Orléans, 2007. http://www.theses.fr/2007ORLE2066.
Texto completo da fonteEl, khawand Toni. "Extraction et hémisynthèse de stilbènes de la vigne et du vin pour une application en santé humaine et végétale". Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0402.
Texto completo da fonteStilbenes are a group of defence molecules produced by grapevine to fight against pathogens. They are consequently found in wine, where they acquire an added value through their proven positive effects on human health. Knowing that the efficacy of stilbenes against some oomycetes and fungus pathogens that attack grapevine increases with their oligomerization degree, the first objective of this thesis was to optimize and proceed to oxidative coupling reactions of resveratrol and ɛ-viniférine extracted from grapevine canes, in the presence of metal salts, in order to produce stilbene oligomers. On the one hand, these hemisynthesis reactions led to the formation of stilbenes with high molecular weight, and to the production of extracts with high antifungal activity against two major grapevine pathogens, Plasmopara viticola and Botrytis cinerea. On the other hand, these oxidative coupling reactions carried out on wine helped study the mechanisms of the oxidative transformation of resveratrol in wine, identify the resulting oligomers and determine the conditions conducive to their formation. Finally, the potential effects of these oligomers on human health were studied, by evaluating the level of their anti-inflammatory activity
Chalopin, Matthieu. "Rôle du récepteur aux œstrogènes dans la cardio et la vasculo-protection induites par les polyphénols du vin rouge". Angers, 2011. http://www.theses.fr/2011ANGE0035.
Texto completo da fonteMillan, Mathieu. "Analyse de la variabilité des traits architecturaux des formes de croissance dans les communautés végétales". Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT151.
Texto completo da fonteThe growth forms of plant have been studied many times but they still represent nowadays a fuzzy set, often modified because of the inconsistency and the heterogeneity of the methods used in their analysis. This lack of precision often leads to an inconsistency of the use of the growth forms as a trait in the studies of plants communities and their dynamics. We tried to remedy this situation by applying to some of them the architectural analysis initiated by Hallé and Oldeman, which has been relevant for the understanding of the tree growth form.This study aimed to 1) interpret these growth forms and their variability by means of architectural concepts, 2) study architectural traits variation within roadsides plants communities during succession and in a mowing context. Our resultats show that 1) the architectural concepts and traits are applicable to herbaceous, treelet and bush grosth forms, 2) the expression of the reiteration is the main source of structural variation of growth forms at specific and intraspecific levels and 3) that traits values are changing during succession within the communities : Plants living at early successionnal stages got a simple architectural unit and reiterate at the base of the individual while plants living at late successional stages got complex architectural unit and acrotonic reiteration.These resultats lead us to discuss the holistic value of the architectural analysis for growth forms charaterisation, of biological processes allowing for growth form variation and the interest of the use of architectural traits in plant communities studies
Mahjoubi, Habib. "Nouvelle stratégie d'amélioration de la productivité végétale en condition de stress environnemental via un meilleur contrôle du cycle cellulaire". Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAJ059/document.
Texto completo da fonteSalt stress is one of the main environmental factors limiting plant growth and yield in cereal crops. It is therefore imperative to develop varieties more tolerant to salt stress in order to increase yield and ensure food security. The signaling pathway linking salt stress perception to cellular response was addressed here by studying RSS1-like proteins in plants. RSS1 (Rice Salt Sensitive 1) protein plays an important role in salt stress tolerance. It acts at the interface of stress perception and developmental control and division in meristems. During this work, the RSS1 counterpart named TdRL1 (Triticum durum RSS-Like 1) was isolated from the durum wheat Tunisian variety "Oum Rabiaa". We have demonstrated that TdRL1 carries the conserved D and DEN-Box motifs involved in the post-translational regulation of the protein. In addition, we show that TdRL1 is the functional homologue of RSS1 since it was able to complement the loss-of-function mutant rss1, hypersensitive to salt stress. In addition, heterologous expression of TdRL1 enhances salt stress tolerance in yeast and in Arabidopsis by increasing germination and reducing the accumulation of reactive oxygen species. Our cytological studies have shown that the TdRL1 protein is cytoplasmic in interphase and is localized at the spindle during mitosis. Remarkably, TdRL1 changes its subcellular localization under salt stress treatment and shows a partial accumulation in the nucleus, highlighting the multifunctional nature of this protein during salt stress response. Our data suggest that under salt stress, TdRL1 plays a role in the regulation of the cell cycle in relation with the microtubule network. Pursuing the study of RSS1-like multifunctional proteins will open up new research areas for the creation of wheat varieties that are more resilient to environmental stresses
Sarry, Jean-Emmanuel. "Etude biochimique & moléculaire de β-D-Glucoside hydrolases de la baie de raisin (Vitis vinifera L. )". Montpellier 2, 2001. http://www.theses.fr/2001MON20059.
Texto completo da fonteSteyer, Damien. "Etude génétique du métabolisme des acides gras et des terpènes aromatiques chez la levure en conditions fermentaires". Strasbourg, 2011. http://www.theses.fr/2011STRA6241.
Texto completo da fonteThis study describes the influence of Saccharomyces cerevisiae gene mutations onto the wine aromatic compounds using candidate gene and genetic approaches. Candidate gene approach: We have shown that Ethyl Ester Biosynthesis 1 (EEB1) appears here to play a key role in the decanoic acid detoxification during the fermentation process. Its allelic background would also explain the high concentration of ethyl decanoate (fruity) in fermentation made with enological yeasts. Geraniol concentration in wine is influenced by the yeast during the fermentation by two pathway : a reduction into citronellol byOYE2 and an esterification by ATF1 and ATF2 which esterified geraniol, geraniol isomer nerol and citronellol leading to a decrease of the monoterpenols concentration. Quantitative Trait Locus (QTL) approach: We identified 23 mQTL. We focused our work on the 4 most relevant mQTL and identified 4 candidate genes, each belonging to one different mQTL. The allelic backgrounds of the ABZ1 and PDR8 genes have an influence on the 2-phenylethanol/acetate and nérolidol production respectively. Deletion of CEM1 and PLB2 have an influence on the ethyl esters and medium chain fatty acid production. Gathering knowledge about genes involved in the volatile compounds metabolism by S. Cerevisiae would offer new ways of controlling the overall wine quality
Benoist, Anthony. "Eléments d'adaptation de la méthodologie d'analyse de cycle de vie aux carburants végétaux : cas de la première génération". Phd thesis, École Nationale Supérieure des Mines de Paris, 2009. http://pastel.archives-ouvertes.fr/pastel-00005919.
Texto completo da fonteAzzimonti, Gustavo. "Diversification de la résistance quantitative à la rouille brune du blé, à partir de la caractérisation des composantes de la résistance". Phd thesis, AgroParisTech, 2012. http://pastel.archives-ouvertes.fr/pastel-00803279.
Texto completo da fonteOswald, Marilyne. "Déterminisme génétique de la biosynthèse des terpénols aromatiques chez la vigne". Université Louis Pasteur (Strasbourg) (1971-2008), 2006. https://publication-theses.unistra.fr/public/theses_doctorat/2006/OSWALD_Marilyne_2006.pdf.
Texto completo da fonteThe floral character of aromatic varieties of Vitis vinifera is partly linked to the presence in the berry skin of monoterpenic alcohols such as geraniol and linalool found in large amounts. Non aromatic grapevine varieties, in contrast, exhibit much lower terpenoid concentrations. Combining genetic, biochemical and molecular approaches, we tried to decipher the metabolic pathway which leads to monoterpenic alcohols synthesis in aromatic grapevine varieties. It is commonly admitted that monoterpenoids arise from geranyl diphosphate (GPP). So we hypothesized that the high yield of monoterpenoids synthesized in aromatic plants requires either an excess of GPP synthesis and/or a specific metabolization of GPP by terpene synthases (TPS). We isolated vGPPS and vFPPS cDNAs encoding putative geranyl diphosphate synthase and farnesyl diphosphate synthase from Vitis vinifera gewurztraminer, muscat and savagnin rose varieties. Both vGPPS and vFPPS from grapevine share 90% and 88% homology with the corresponding enzymes from Arabidopsis thaliana. A functional analysis in yeast Saccharomyces cerevisiae using adapted mutants strains led us to demonstrate the farnesyl diphosphate activity of vFPPS. In contrast, this approach failed to reveal the end product of vGPPS. To determine the effect of vGPPS and vFPPS on the terpenoid biosynthesis pathway, we expressed in yeast these two cDNAs in combination with the Ocimum basilicum geraniol synthase and the Clarkia breweri linalool synthase. Under these experimental conditions, we showed that GPP amount is an important factor of the pathway together with terpene synthases which are the basic actors. Altogether, our data suggest that the functional analysis approach in yeast was an adequate system to help us for deciphering the first basic steps of the grapevine terpenoid biosynthesis pathway. This approach must now be conducted in grape to clarify differences between aromatic and non aromatic grapevine genotypes
Silvestre, Virginie. "Étude des interactions entre la cellulose et les xyloglucanes via des systèmes modèles de parois végétales primaire". Nantes, 2004. http://www.theses.fr/2004NANT2026.
Texto completo da fonteMaury, Chantal. "Etude des phénomènes impliqués dans les étapes de collage en oenologie". Montpellier, ENSA, 2001. http://www.theses.fr/2001ENSA0012.
Texto completo da fonteThe aim of that work was to better understand the behaviour of gelatines to better control this step, to estimate the potential of: plant proteins in wine fining and to understand the impact of fining treatment on wine astringency. Phenolic compounds were analysed before and after fining treatment of a model wine and six different wine with gelatines having different MW and plant proteins. Simple phenolic compounds precipitated, neither with gelatines, nor with plant proteins. Results of condensed tannins analysed by thiolysis showed that aIl gelatines precipitate the same level of condensed tannins. They selectively precipitated highly polymerised and highly galloylated tannins. Moreover, the more hydrolysed gelatines precipitated tannins which were more polymerised than those precipitated by the less hydrolysed one. The plant proteins tested in that work (wheat, rice and lupinus), precipitated a lower level of tannins than gelatines. Their selectivity for tannins was dependent of the protein used, but sorne of them were as selective tan gelatines. Polysaccharides and glycerol do not precipitate but influence the level of precipitation and the selectivity of proteins for polymerised tannins. Our results showed the presence of residual fining pro teins in wine after fining, Presumably as soluble tannins-proteins and tannins-proteins-polysaccharides complexes. Comparison between sensory evaluation and tannins analysis suggested than the reduction of astringency by fining treatment is due to the removal of highly polymerised. And highly galloylated tannins which are responsible for astringency, or to the presence of soluble tannins-pro teins complexes which reduce tannins-salivary proteins interaction, thus diminishing the astringency perception
Raymond, Olivier. "Domestication et sélection dirigée chez le rosier : analyse historique via les phénotypes morphologique, chimique et biochimique". Lyon 1, 1999. http://www.theses.fr/1999LYO10154.
Texto completo da fonteBrault, Julien. "Développement d'un procédé innovant de dégradation enzymatique des parois végétales pour la production de bioéthanol seconde génération". Thesis, Toulouse, INPT, 2013. http://www.theses.fr/2013INPT0088.
Texto completo da fonteLignocellulosic biomass transformation processes in order to produce second generation bioethanol are actually widely studied all around the world but still not yet competitive compare to the first generation. The limiting key factors of the different processes are: the pre-treatment efficiency and costs, the enzymatic hydrolysis yields, and the co-fermentation C5-C6. A continuous plant matter deconstruction process, compacting a thermo-mechanico-chemical pre-treatment using alkali solution with an enzymes injection in twin-screw extruder, called bioextrusion, is developed in this study. It allows preparing the cellulosic material at a high dry matter content (>20%), to a possible simultaneous saccharification and fermentation (SSF). This continuous treatment may extract a big part of hemicelluloses (until 97%) and lignin (>50%) and configures cellulose to a better accessibility and a start of its depolymerisation by enzymes cocktail during the bioextrusion. Several raw matters (Sweet Corn Cob and Spathe, Blue Agave Bagass, Oil Palm Empty Fruit Bunch, Barley Straw, Eucalyptus Residue, Grape Pruning Residue and Sugarcane Bagass) have been characterized and theirs behaviours toward to the process were compared. Evolutions of these matters compositions throughout the process and their hydrolysability have been studied. Further to the treatment, an improvement of the saccharification yields in reactor (24h reaction time at 20% consistency) has been obtained on these matters (until 85% of theoretical C6 and 70% of theoretical C5-C6). The not optimized fermentation yields reach a maximum of 85% of theoretical converted C6 sugars, 65% of theoretical converted C5-C6 sugars, and an ethanol concentration of 15g/100g dry matter extrudate. The whole ethanol production process (with addition of energy from the recovery of the by-products) is achieved with a “consumed/produced energy” ratio of 0.5-0.6. The new process presents the advantages to minimize the energy consumption by operating low temperatures, to minimize water consumption by working at low liquid/solid ratio, to not produce fermentation ‘s inhibitors and to be quick, compact, continuous and adaptable to different biomasses
Escot, Sandra. "Contribution à l'étude des protéines glycosylées des levures et à leurs interactions avec les polyphénols des vins rouges". Dijon, 2003. http://www.theses.fr/2003DIJOS035.
Texto completo da fonteAl-Awwadi, Najim Abbas. "Effets de composés polyphénoliques de vin et de raisins dans des modèles expérimentaux de pathologies chroniques : diabète et hypertension". Montpellier 1, 2004. http://www.theses.fr/2004MON13501.
Texto completo da fontePoitou, Xavier. "Contribution à la connaissance aromatique des vins rouges : Approche sensorielle et moléculaire des nuances « végétales, vertes » en lien avec leur origine". Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0407/document.
Texto completo da fonteThe green aromas family includes in red wines a large diversity of nuances. First, this study revealed that these nuances are not directly related to known compounds (e.g. 2-méthoxy-3-alkylpyrazines, C6 alcohols). After a sensory definition, the molecular determinants of these aroma nuances were investigated based on fractionation strategies including HPLC and vacuum distillation then MDGC-O-MS. A first source of nuances associated with grapes ripeness was developed. The presence of 1,8-cineole (eucalyptol) with a varietal origin was evidenced in Cabernet Sauvignon wines. The ability of a grape variety to produce significant amounts (Fer Servadou) and an exogenous origin associated with the presence of Artemisia species in vineyards (Artemisia verlotiorum) were also highlighted. Another origin, related to the pressing of grape marc was then considered. This study shown the connection between the aromatic category of press wines and the green aromas. Furthermore, it revealed the presence of odoriferous molecules including (Z)-4-heptenol, with a sensory contribution, associated to the increase of pressure in the press tank, but not for the majority of C6 alcohols. It also suggested the involvement of several carbonyl compounds in the characteristic odor of press wines. The influence of technological parameters (without oxygen, pressure, SO2, malolactic fermentation) was also specified. Finally, this study revealed the presence of methyl salicylate as a plant defense marker against several fungal diseases (downy mildew, black rot, esca) and as a contributor to fresh green aromas of certain red wines
Bergeron, Marc. "Caractérisation du recouvrement végétal et des pratiques agricoles à l'aide d'une image TM de Landsat au nord du Viet Nam". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0015/MQ61711.pdf.
Texto completo da fontePalla, Florence. "Caractérisation et distribution spatiale des groupements végétaux de la mosaïque forêt-savane du Parc National de la Lopé (Gabon) : apport des traits caractéristiques de la végétation (traits d'histoire de vie) et des images radar PALSAR". Paris 6, 2011. http://www.theses.fr/2011PA066377.
Texto completo da fonteLefeuvre, Dorothée. "Réactions de substitution nucléophile et d'oxydation des ellagitannins C-arylglycosidiques". Bordeaux 1, 2006. http://www.theses.fr/2006BOR13271.
Texto completo da fonteIsorez, Géraldine. "Contribution à la chimie des flavonoïdes : Accès à des analogues de pigments du vins rouges". Université Louis Pasteur (Strasbourg) (1971-2008), 2007. https://publication-theses.unistra.fr/public/theses_doctorat/2007/ISOREZ_Geraldine_2007.pdf.
Texto completo da fonteNguyen, Quang Hung. "Study on bioaccumulation and integrated biorefinery of vegetable oil and essential oil of Coriander (Coriandrum sativum L.)". Phd thesis, Toulouse, INPT, 2015. http://oatao.univ-toulouse.fr/16038/1/Nguyen_QH.pdf.
Texto completo da fonteHis, Cédric. "Etude de faisabilité des procédés de transestérification enzymatique d’huiles végétales usagées pour la synthèse de biodiesel et évaluation environnementale par une approche en analyse de cycle de vie". Thesis, Lille 1, 2014. http://www.theses.fr/2014LIL10190.
Texto completo da fonteIn our society, energy and environmental questions are becoming important issues, « green » alternatives to conventional processes are in continuous development. In particular, works on biodiesel synthesis from vegetable oil have strongly increase during these last 20 years. The use of pure vegetable oil from seeds for human feed being critical, substitute products are used for biodiesel synthesis. Withnin this framework,this PhD thesis treats on the synthesis of biodiesel from used vegetable oil by enzyme methods .The transesterification reaction has been throughly studied as well on reaction conditions (temperature, enzyme/substrate ratio, kinetic reaction), as on the type of enzyme (nature of the organism of origin of the enzyme, in solution or immobilized) or on reactor type (BSTR, PBR or CSTR). In some conditions, the conversion has been total (> 99 %), allowing for atmospheric emission testing of an unrefined biofuel. Separation of the different constituents of biofuel by membrane process has been carried out in order to obtain a biodiesel made up only of esters, ethanol and glycerol ; these last two constituents has been removed by evaporation and decantation. The product’s environmental footprint has been calculated by the life cycle assessment method and compared with the impact of the first generation biofuels
Korboulewsky, Nathalie. "Valorisation d'un compost de boues urbaines dans un vignoble méditerranéen : conséquences sur le sol, le végétal, et la qualité du vin". Aix-Marseille 1, 2001. http://www.theses.fr/2001AIX11060.
Texto completo da fonteKouame, Bosson Antoine. "Impact santé des procédés de préparation des aliments riches en polyphénols : chocolat, vin, thé, …". Montpellier 1, 2006. http://www.theses.fr/2006MON13518.
Texto completo da fonteWe isolated, identified the epicatechin, the catechin, dimers B2 and B5 of the cocoa, in order to study their properties on the cancerous cells T47D. These compounds are potential agonists of membrane androgen receptors and could be used as testosterone-protein conjugates for the management of tumors, in which, application of testosterone-BSA induces regression. We determined the presence in chocolate of chiral compounds as: (+)-catechin, (-)-catechin, (-)-epicatechin, dimers B2 and B5. The hemi synthesis of monomers from cocoa gave the following enantiomers: (+)-epicatechin and (-)-catechin. The rearrangement of the dimer B2 give: epicatechin, (-)-catechin and the 8,9- cis-9-14-trans-3,4,9,1O-tetrahydro-2H,8H-pyrano[2,3-h]chromene, of which results on the cancerous cells U266, K562, THP1 and Rajis, are very near of those of the resveratrol. We can say that it could have a biologic interest of the industrial treatments of the chocolate for the consumer
Zeitoun, Rawan. "Procédés de fractionnement de la matière végétale : application à la production des polysaccharides du son et de la paille de blé". Thesis, Toulouse, INPT, 2011. http://www.theses.fr/2011INPT0017/document.
Texto completo da fonteWheat bran and wheat straw are two by-products abundant and renewable, rich in hemicelluloses, but still not well valued. In order to extract these hemicelluloses characterized by their several interesting properties (film-forming, thickening, emulsifying, stabilizing…), a fractionation process was developed. This process consisted, after alkaline extraction, to purify the hemicellulosic extracts obtained. Two techniques were used: ultrafiltration and chromatography on anion exchange resin. The ultrafiltration allowed to concentrate the extracts and to purify them by removing in the permeate, the contaminating molecules, mostly free sugars and minerals. The main limiting factors of this stage were the extracts viscosity and the fouling of the membranes. The percolation on the resin discoloured the extracts and allowed to produce hemicellulosic powders with lighter colours and that by capturing the coloured compounds such as molecules with phenolic groups. The combination of the two techniques allowed the production of purified hemicelluloses; the purity was about 60%. The extrapolation of the process at a pilot scale using a twin-screw extruder allowed to obtain hemicelluloses with a purity of 40%
Beuve, Francois xavier. "Problématisation, investigations et apprentissages dans les sciences de la vie. : Etude didactico-pédagogique des conditions de possibilité pour des investigations empiriques problématisantes, dans deux domaines biologiques : nutrition et reproduction végétales". Thesis, Normandie, 2017. http://www.theses.fr/2017NORMC010/document.
Texto completo da fonteFor several years now, and with reference to the rationalist epistemology of Bachelard, Canguilhem and Popper, the relationship between problem, scientific knowledge and learning is the focus of extensive educational research. Language holds a first choice place at the heart of this interaction, which explains more particularly the importance given to scientific debate, and whose representation of the outcome, in terms of problematizing activity, is enabled by creating “spaces of constraints and needs”, which build on the fundamental distinction of an empirical thesaurus and the thesaurus of the model [or the models], and also on the equally fundamental distinction of the apodictic and assertoric, that is what is the contingency and the necessary. Furthermore, though the scientific debate seems centered around the construction of the problem at stake, another question is raised, within the conceptual framework of problematization that we mobilize, the very function of empirical investigations, according to their own structure : are still involved in the construction of the problem at stake and, where appropriate, under what conditions ? Based on these recent findings, this research work aims at the conceptualization, the implementation and the analysis of two teaching-learning science sequence, in a class of year 9 and 10, so as to highlight some elements which may participate in the scientific case of problematization to be surveyed, more particularly in the articulation of the construction to solve the problem at stake
Rageot, Maxime. "Les substances naturelles en Méditerranée nord-occidentale (VIe-Ier millénaire BCE) : chimie et archéologie des matériaux exploités leurs propriétés adhésives et hydrophobes". Thesis, Nice, 2015. http://www.theses.fr/2015NICE2021/document.
Texto completo da fonteNatural substances and transformed organic products used for their adhesive and hydrophobic properties are rarely considered for the pre- and protohistorical periods in the North Western Mediterranean. These materials can however provide technological, economic, social and environmental information about ancient societies.A biomolecular approach was applied to answer questions related to the different types of natural substances exploited by ancient communities. Plant and animal products were identified as raw materials (resins, beeswax, fats or bitumen), or as processed (birch bar tar, pine tar, and mixtures).Experimental work allowed a better understanding of the chaîne opératoire required for the production of birch bark tar. Results showed that it is possible to distinguish between the different manufacturing processes based on molecular criteria.To investigate procurement strategies of plant raw materials, archaeobotanical data was integrated using a spatial approach.The analysis carried out has shown that Birch bark tar was found to be the major product utilised during the Neolithic, its method of production varying depending on the chrono-cultural area. This resource was also sometime transferred. Bitumen, on the other hand, was exploited only when locally available. A diversification of materials (beeswax and Pinaceae resins), suggesting different methods of procurement and processing, was mostly apparent for the Chassey culture, where there appears to be intensification in the use.During the Iron Age, pine tar is the major product in the Mediterranean area. Birch bark tar was only identified in Corsican protohistorical societies
Gamon, Guillaume. "Incorporation de fibres végétales dans des matrices thermoplastiques biosourcées et biodégradables par extrusion bi-vis pour la production de matériaux biocomposites moulés par injection". Thesis, Toulouse, INPT, 2013. http://www.theses.fr/2013INPT0029.
Texto completo da fonteIncorporation of vegetal fibres, differing by their source, their chemical composition and their shape, have been performed by twin screw extrusion in two thermoplastic matrices: the poly(lactic acid) and the thermoplastified wheat flour. These two biobased and biodegradable matrices have also different chemical character and thermo-mechanical properties. Fibre incorporation up to 40 % in weight considerably modified both matrix properties and improved several weaknesses (thermal stability, lack of stiffness…). Miscanthus fibres have been selected as best improvers for properties of both matrices. Materials properties were adjusted with a formulating work (addition of plasticizers) and whole process optimization, until injection-molding. Fibre incorporation in a compatibilized blend of the two matrices was also tested and performed in a one step extrusion process, including flour thermoplasticization, polymer blending and fibre dispersion
Ngo, Duc chinh. "Développement d’un nouveau éco-béton à base de sol et fibres végétales : étude du comportement mécanique et de durabilité". Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0885/document.
Texto completo da fonteThe ecological design of structures and the sustainable development is nowadays of high importance in the construction industry. Thus, alternative building materials such as soil concrete containing a proportion of various ecological components are of high importance nowadays. The aim of producing ecological concrete is to reduce the consumption of cement and thus the CO2 production, to provide alternatives to the impoverishment of resources and to reduce the energy consumption in the production process.In recent years, many changes have been observed in the construction methods with the aim to replace traditional concrete by alternative construction materials such as concrete containing a high proportion of various ecological component called "green" while maintaining acceptable properties for the desired application. For instance, constructions made of cost effective raw soils are of real interest since the thermal and acoustic properties are more important than that of ordinary concrete. However, more researchs are needed in order to have a better understanding of their mechanical properties and their durability.This study aims to optimize the composition of a new ecological concrete constituted of upgraded excavated soil. Several soil concrete mixtures, composed of different proportions of clayey soil, sandy soil and small quantities of cement, lime and hemp fibers have been tested. The mineralogy and chemical composition of clayey soil was studied by X-ray diffraction (XRD) analysis, and by Environmental Scanning Electron Microscopy (ESEM) coupled with the X-Ray Energy Dispersive Spectrometry (EDS). The casting of the concrete mixtures has been realized by vibration, as ordinary concrete, to obtain the required workability on construction sites.Compressive tests have been carried out on samples at different curing time and conditions. The ultrasonic non-destructive technique has been used for monitoring the hardening of soil concrete in function of the curing conditions. As soil concrete presents important volumetric change that can cause the infiltration of water and impact their durability, an experimental investigation on autogenous and drying shrinkage is reported. Water porosity and water absorption tests have been also carried out to evaluate the transfer property of the porous material. The carbonation of this concrete was also evaluated. The durability of the soil concrete was examined by following the deferred deformations and more particularly the endogenous shrinkage and desiccation as well as the flexural creep
Shoar-Ghafari, Almas. "Caractères cytologiques des grains protéiques et des globoïdes, dans les graines en vie latente d'Helianthus annuus l. (composées) et d'Alisma plantago l. (alismacées)". Paris 6, 1986. http://www.theses.fr/1986PA066598.
Texto completo da fonteKei, Nikolina-Antonia. "L' esthétique des fleurs : kosmos, poikilia et charis dans la céramique attique du VIe et Ve siècle avant J.C". Paris, EHESS, 2010. http://www.theses.fr/2010EHES0120.
Texto completo da fonteAlthough flowers on attic pottery are mainly ornamental motifs, it would be an error to limit their function to a pure aestheticization of the ceramic surface. They are also figurative agents that support the architecture of the vase and, at the same time, shape the spectator's perception of the narrative scene: floral frames and floral motifs floating inside the scene echo and emphasize the action. Ln other words, they participate to the kosmesis, operation that refers to ornament as well as order and arrangement. Floral ornaments appear on Athenian vases but also on abjects depicted in the scenes on Athenian vases, such as drapery, armour, jewellery, sceptres, mirrors, furniture, architectural elements and vessels. They con vey and visualize the notion of poikilia, of kosmos, and that of charis, three notions which assign to ail these luxurious and prestigious objects, the essence of a daidalon, of an agalma. The role of the floral ornaments is to highlight the presence and therefore the significance of these objects inside the image. Nevertheless, flowers do not qualify only objects but also mortal figures and deities, different kinds of relations between erotic partners, friends, family members, humans and gods, and finally festival activities and celebrations, such as athletic and musical competitions, symposia, dances and weddings. In other words, flowers, vehicles of visual and olfactory sensations, magnify figures and, at the same time, supply the vase scenes with a reservoir of values linked to charis and its declinations personified by the three Charites, Aglaia (physical beauty and youth), Thalia (generosity, favour and gift) and Euphrosyne (jubilation and pleasure of the senses)
Uitterhaegen, Evelien. "Study of the integrated biorefinery of vegetable and essential oil in Apiaceae seeds". Thesis, Toulouse, INPT, 2018. http://www.theses.fr/2018INPT0045.
Texto completo da fonteCoriander fruits of French origin were identified as a rich source of a high-quality vegetable oil, with a high petroselinic acid content, and essential oil. An innovative extraction system was designed and developed using twin-screw extrusion technology and resulted in the recovery of a novel flavored coriander oil with high added value, as well as a hydrosol product with a high essential oil concentration and a press cake with an important protein fraction. The press cake was shown valuable as a natural binding agent for the production of renewable materials from coriander straw, a crop residue, and led to binderless boards with a high performance-cost ratio. Simultaneously, the coriander straw fibers displayed good reinforcing capacity as a natural filler in thermoplastic biocomposites from polypropylene or biopolyethylene, resulting in cost-effective materials with attractive properties. This work thus presents a strong contribution to the setup of a true integrated biorefinery for coriander fruits and its industrial implementation on a relevant production scale