Thesis (Ph. D.)--University of Wisconsin--Madison, 1946. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves [118]-120).

Submitted by AMELIA ALIK DE FREITAS ZUMBA null (amelia.zumba@novelis.com) on 2016-09-28T20:39:28Z No. of bitstreams: 1 Mestrado - v.final.docx: 10697220 bytes, checksum: 300f19fc7542fa3470679a32d14fa78c (MD5) / Rejected by Ana Paula Grisoto (grisotoana@reitoria.unesp.br), reason: Solicitamos que realize uma nova submissão seguindo as orientações abaixo: A versão final da dissertação/tese deve ser submetida no formato PDF (Portable Document Format). O arquivo PDF não deve estar protegido e a dissertação/tese deve estar em um único arquivo, inclusive os apêndices e anexos, se houver. Por favor, corrija o formato do arquivo e realize uma nova submissão. Agradecemos a compreensão. on 2016-09-29T18:34:10Z (GMT) / Submitted by AMELIA ALIK DE FREITAS ZUMBA null (amelia.zumba@novelis.com) on 2016-09-29T20:05:22Z No. of bitstreams: 1 Mestrado - v.final.pdf: 2498608 bytes, checksum: df0eee2f47b660e50ddb61b07e057fb8 (MD5) / Approved for entry into archive by Juliano Benedito Ferreira (julianoferreira@reitoria.unesp.br) on 2016-09-30T16:44:59Z (GMT) No. of bitstreams: 1 zumba_aaf_me_guara.pdf: 2498608 bytes, checksum: df0eee2f47b660e50ddb61b07e057fb8 (MD5) / Made available in DSpace on 2016-09-30T16:44:59Z (GMT). No. of bitstreams: 1 zumba_aaf_me_guara.pdf: 2498608 bytes, checksum: df0eee2f47b660e50ddb61b07e057fb8 (MD5) Previous issue date: 2016-08-02 / Há uma crescente demanda pelo uso de materiais na indústria em geral, que consigam aliar sustentabilidade e performance, onde o alumínio enquadra-se nestes dois requisitos. A liga AA5182 apresenta propriedades importantes, tais como: baixa densidade, alta resistência mecânica e à corrosão, bem como boa conformabilidade. Neste estudo, foi realizada a definição de uma região crítica na qual foram realizados três testes, simulando diferentes ciclos de homogeneização desta liga, através da realização do ciclo de homogeneização em menores tempos que o ciclo original, antes do envio para a laminação a quente e avaliando características superficiais e microscópicas, para que não exista impacto negativo nos processos subsequentes. Após as análises comparativas realizadas, percebeu-se que o teste onde o patamar de aquecimento foi abaixo da temperatura de liquação de precipitados de magnésio apresentou melhor resultado, proporcionando a redução do tempo de ciclo sem o aparecimento de linhas pretas, oriundas da oxidação do magnésio, permitindo assim, a redução do tempo de ciclo de homogeneização. / There is a growing demand for the use of materials in the industry in general, they can combine sustainability and performance, where aluminum fits these two requirements. The alloy AA5182 has important properties such as: low density, high mechanical resistance and corrosion resistance as well as good formability. First of all, this study was conducted to define a critical region in which there were three tests, simulating different homogenization cycles of this alloy, by conducting the homogenization cycle times smaller than the original cycle, prior to shipment to the hot rolling and evaluating superficial and microscopic characteristics, so that there is no negative impact on subsequent processes. After that, comparative analyzes it was observed that the test where the heating level was below the magnesium precipitates liquation temperature showed better results, providing a reduction in the cycle time without the appearance of black streaks, derived from the magnesium oxidation, thus, reducing the homogenization cycle time.

Le polychlorure de vinyle (PVC) plastifié est un plastique très présent dans les collections patrimoniales et dans un état de conservation jugé souvent médiocre. Les dégradations les plus fréquentes sont l’exsudation et la perte de souplesse des objets qui sont liées à la migration progressive du plastifiant vers la surface du matériau.Les travaux de thèse visaient à mieux comprendre les processus d’altération des objets en PVC plastifiés et à préconiser des conditions de conservation et des traitements de restauration. Cette étude a été réalisée en parallèle sur des PVC de formulation simplifiée et sur des PVC anciens vieillis naturellement en musée. La cinétique de migration du plastifiant et les modifications structurales des chaînes PVC ont été caractérisées au cours d’un vieillissement artificiel des films réalisé dans les conditions les plus représentatives d’un environnement muséal d’exposition ou de conservation.L’impact du nettoyage des surfaces a été étudié en terme d’efficacité mais surtout de dégradation ultérieure du PVC et notamment de réapparition des exsudats. L’effet de différents conditionnements sur le vieillissement des PVC souples, nettoyés ou non, a également été évalué. Des matériaux d’emballage régulièrement utilisés par les restaurateurs ont été considérés.Ces travaux ont permis d’apporter un éclairage sur l’effet des méthodes utilisées lors de la restauration et la conservation des œuvres en PVC plastifié. / Plasticized polyvinyl chloride (PVC) is a plastic widely used in patrimonial collections but its state of preservation is often considered as poor. The most frequent degradations are the exudation and the loss of flexibility of objects which are related to the progressive migration of the plasticizer towards the surface of the material.The project thesis aimed to better understand the alteration of plasticized PVC objects and predict conditions of conservation and restoration treatments.This study was conducted with both a simplified formulation of PVC and an ancient PVC naturally aged in museum.The kinetics of plasticizer migration and structural modifications of PVC chains were characterized during artificial ageing of films conducted through the most representative conditions of a museum environment of exposure or conservation.The impact of surface cleaning was studied in terms of efficiency but also subsequent degradation of the PVC, in particular the recurrence of exudates. The effect of different conditionings on the ageing of flexible PVC, either cleaned or not, was also estimated. Packaging materials frequently used by conservators have been considered.This work allowed achieving new insights on the effect of methods used for conservation and preservation of plasticized PVC artefacts.

Les travaux réalisés lors de cette thèse s’effectuent dans le cadre du projet FIXAPIN. Ce projet, financé par la région Nouvelle Aquitaine, est mené en collaboration avec différentes entreprises (Gascogne Bois, Bardage Bois Neoclin, Lesbats Scieries d’Aquitaine, Scierie Labadie et FPBOIS) spécialisées dans le domaine du sciage du bois de pin maritime et l'Institut technologique FCBA. L’objectif du projet est de limiter voire d’empêcher l’exsudation de la résine généralement observée sur la surface des planches de bois de pin maritime utilisées en extérieur comme bardage. L’exsudation de la résine est un frein important à l’utilisation de ce bois en extérieur et ces recherches s’inscrivent dans une démarche d’amélioration continue de la qualité des produits de la filière du pin maritime.Le bois de pin maritime peut présenter un taux de résine supérieur à 10 % de sa masse. La résine est constituée d’environ 70 % de colophane (fraction solide) et de 30 % d’essence de térébenthine (fraction liquide et volatile). À la suite d’essais préliminaires, les recherches réalisées lors de cette thèse se sont concentrées sur l’optimisation du cycle de séchage du bois afin de fixer la résine dans les planches. Les propriétés thermiques de la résine associée à des analyses physico-chimiques ont été étudiées afin de mettre en place des procédures de séchage optimisées ayant pour but d’augmenter la température de ramollissement de la résine à un seuil supérieur à la température maximum atteignable par un bardage extérieur.Les résultats ont permis de démontrer l’efficacité d’un séchage/traitement thermique du bois à haute température (> 120 °C) permettant d’envisager la poursuite de ces travaux aux échelles pilotes puis industrielles. De plus, des séchages longs à basse température (< 60 °C) peuvent également représenter une voie prometteuse concernant le séchage du bois en séchoir traditionnel. / The work realised in the context of this thesis is carried out within the FIXAPIN project. This project, funded by the Nouvelle Aquitaine council, is carried out in collaboration with several companies (Gascogne Bois, Bardage Bois Neoclin, Lesbats Scieries d'Aquitaine, Scierie Labadie and FPBOIS) specialized in the sawing of maritime pine wood and the FCBA Technological Institute.The aim of the project is to limit or even to prevent the exudation of the resin generally observed on the surface of maritime pine wood boards used outdoors as wood siding. The resin exudation is a major constraint to the external use of this wood and this research project is part of a continuous improvement process of the maritime pine products quality.Maritime pine wood can have a resin amount greater than 10% of its mass. The resin consists approximately of 70% rosin (solid fraction) and 30% turpentine (liquid and volatile fraction). Based on preliminary tests, the research carried out during this thesis focused on optimizing the wood drying process in order to fix the resin in the wood boards. The thermal properties of the resin associated with physico-chemical analyses were studied in order to implement optimized drying procedures to increase the resin softening temperature to a threshold higher than the maximum temperature attainable by an exterior siding.The results have demonstrated the effectiveness of drying / heat treatment of wood at high temperature (> 120 ° C) to allow the pursuit of this work at pilot than industrial scales. Furthermore, long drying at low temperatures (<60 ° C) may also be a promising approach regarding the wood drying process in traditional kilns.

[Truncated abstract] The highly weathered, phosphorus-fixing soils of Western Australia require large amounts of P fertiliser to produce acceptable crop yields. Chickpea (Cicer arietinum L.) is an important leguminous crop that is increasingly used in rotations with wheat (Triticum aestivum L.), Western Australia’s major crop. Chickpea and a range of other species exude P-mobilising carboxylates into the rhizosphere. Plants that exude carboxylates may need less P fertiliser or may use P in the soil that is unavailable to other plants. There is a wealth of information about P mobilisation and carboxylate exudation by white lupin; in contrast, research on carboxylate exudation by chickpea is fairly limited. The major aim of this PhD research project was to investigate the relationships between exudation of carboxylates and soil and plant P status for chickpea ... In conclusion, whereas carboxylate exudation of plants such as white lupin is clearly targeted at P acquisition, chickpea showed constitutive carboxylate exudation mainly of malonate into the rhizosphere in a series of experiments, each with a different design. Unlike white lupin, chickpea forms associations with mycorrhizal fungi that may improve plant P status. Some of the functions of constitutive carboxylate exudation by chickpea may include P acquisition and deterring microorganisms, but the exact reasons and mechanisms remain unresolved.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Moringa oleifera (moringa) à uma espÃcie pertencente à famÃlia Moringaceae que se caracteriza por ser muito resistente a insetos e fungos. Trabalhos prÃvios realizados por nosso grupo de pesquisa revelaram a presenÃa de proteÃnas ligantes à quitina em sementes de moringa, dentre elas a Mo-CBP3, sugerindo uma correlaÃÃo positiva entre essa proteÃna e a resistÃncia da planta. No inÃcio do desenvolvimento da planta, para que ocorra a germinaÃÃo, deve haver a embebiÃÃo da semente, um processo seguido pela exsudaÃÃo. Na exsudaÃÃo, compostos do metabolismo primÃrio e secundÃrio sÃo externalizados da semente, alguns deles exercendo aÃÃo de defesa da nova planta ao impedirem o ataque de herbÃvoros e/ou patÃgenos. O presente trabalho teve como objetivos caracterizar o exsudato de sementes de moringa quanto à composiÃÃo bioquÃmica e atividade biolÃgica e investigar a presenÃa de Mo-CBP3 no exsudato, visando contribuir para o estabelecimento de seu papel fisiolÃgico. Inicialmente, foram estabelecidas as condiÃÃes de exsudaÃÃo, dando Ãnfase ao tempo e solvente. Uma maior exsudaÃÃo de proteÃnas foi observada em sementes embebidas com Ãgua destilada por 24 horas. Esse exsudato mostrou a presenÃa de atividades inerentes a metabÃlitos primÃrios (protease, &#946;-1,3-glucanase, quitinase, inibidor de tripsina e inibidor de papaÃna) e secundÃrios (saponinas e esteroides). Mo-CBP3 foi tambÃm detectada no exsudato, usando anticorpos policlonais anti-Mo-CBP3. A presenÃa de Mo-CBP3 no exsudato de sementes de moringa foi confirmada apÃs este ter sido submetido à cromatografia em matriz de quitina, procedida pela anÃlise atravÃs de dot bloting e eletroforese em gel de poliacrilamida. Os dados obtidos mostraram que o material retido na matriz de quitina corresponde a 0,26% do total de proteÃnas exsudadas, à reconhecido pelo anticorpo anti-Mo-CBP3 e apresenta perfil eletroforÃtico similar ao da Mo-CBP3 purificada de sementes de moringa. Na avaliaÃÃo da atividade deste exsudato frente à fitopatÃgenos, aÃÃo contra fungos nÃo foi detectada, nas condiÃÃes de ensaio empregadas, exceto para Candida parapsilosis que mostrou uma discreta reduÃÃo na taxa de crescimento. Contrariamente, uma potente atividade contra nematoide foi verificada, tendo sido o exsudato de sementes capaz de causar atà 100% de mortalidade para indivÃduos de Meloidogyne incognita em estÃgio de J2. Quando investigada a presenÃa de Mo-CBP3 em raiz, um ÃrgÃo vegetal que apresenta o fenÃmeno de exsudaÃÃo e, tambÃm, à capaz de interagir diretamente com o nematoide, resultados positivos foram encontrados. De fato, Mo- CBP3 està presente em raÃzes de moringa, jà nos estÃgios iniciais do desenvolvimento, conforme resultados mostrados por ELISA e atravÃs da tÃcnica de RT-PCR. Os dados, em conjunto, sugerem que no fenÃmeno da exsudaÃÃo, proteÃnas devem desempenhar funÃÃes essenciais e que, no caso da moringa, Mo- CBP3 jà participa nos estÃgios iniciais do desenvolvimento dessa planta arbÃrea, papel este que pode estar relacionado com a proteÃÃo contra patÃgenos. / Moringa oleifera (moringa) is a species belonging to the family Moringaceae which is characterized as having high resistance to insects and fungi. Previous work carried out by our research group revealed the presence of chitin-binding proteins in moringa seeds, among them Mo-CBP3, suggesting a positive correlation between this protein and the plant resistance. At the onset of the new plant development, for germination to occur, seed imbibition is required, a process followed by exudation. In exudation process, primary and secondary metabolites are released in the medium outside the seeds, some of them protecting the new plant against herbivores and/or pathogens. This study aimed to characterize the chemical composition and biological activities of moringa seed exudate and to investigate the presence of Mo-CBP3 in the exudate, in order to contribute to the establishment of its physiological role. Initially, the best conditions for exudation were established, emphasizing the time and solvent. A higher exudation of seed proteins was observed in distilled water after 24 hours. This exudate showed the presence of activities related to primary (protease, &#946;-1,3- glucanase, chitinase, trypsin inhibitor and papain inhibitor) and secondary (steroid and saponins) metabolites. Mo-CBP3 was also detected in the exudate, using polyclonal antibodies anti-Mo-CBP3. The presence of Mo-CBP3 in the moringa seed exudate was confirmed after chromatography on chitin matrix and analyses by dot blotting and polyacrylamide gel electrophoresis. The data obtained showed that the retained material on the chitin matrix corresponds to 0.26% of the total protein, it is recognized by anti-Mo-CBP3 and has electrophoretic profile similar to that of Mo- CBP3 which was purified from moringa seeds. In the activity tests to pathogens, the seed exudate showed no antifungal activity, under the conditions used, except for Candida parapsilosis which had a slight reduction in its growth rate. In contrast, a potent activity against nematode was found as the seed exudate was able to cause a mortality rate up to 100% of Meloidogyne incognita in J2 stage. When investigated the presence of Mo-CBP3 in moringa hoots, a plant organ that shows the exudation phenomen and is also able to interact directly with the nematode, positive results were found. In fact, Mo-CBP3 is present in moringa hoots, in the initial stages of the plant development, according to the results shown by ELISA and RT-PCR. The data, taken together, suggest that in the exudation phenomen, proteins must play essential roles. In the case of moringa, Mo-CBP3 already participates in the initial stages of development of this tree species, playing a role that must be related to protection against pathogens.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / A exsudaÃÃo à um mecanismo de defesa apresentado por sementes que consiste na liberaÃÃo de molÃculas para o solo durante o processo de germinaÃÃo. Esses exsudatos, compostos essencialmente de proteÃnas e metabÃlitos secundÃrios, atuam interferindo no desenvolvimento de microrganismos, representando fontes para prospecÃÃo de molÃculas de defesa com potencial biotecnolÃgico, voltadas ao controle de patÃgenos de solo. Nesse contexto, a soja se destaca [Glycine max (L.) Merrill] como sistema ideal ao estudo das interaÃÃes planta-patÃgeno, visto seu grande valor econÃmico e o alto teor de proteÃnas de seus grÃos. Este trabalho teve como objetivos caracterizar a composiÃÃo dos exsudatos de sementes de dois cultivares de soja, com diferentes Ãndices de desempenho em resposta ao nematoide das galhas Meloidogyne incognita, e avaliar seus efeitos in vitro e in vivo sobre este fitopatÃgeno. Exsudatos foram obtidos a partir de sementes de soja (cultivares BRS-Pala: suscetÃvel; BRS-Macota: resistente), embebidas em acetato de sÃdio 0,1 M, pH 5,0, por 18 horas. A anÃlise proteÃmica comparativa livre de gel que permitiu a identificaÃÃo de diversas proteÃnas relacionadas à defesa vegetal, tais como a aglutinina da soja, os inibidores de tripsina do tipo Kunitz e Bowman-Birk e proteÃnas relacionadas à patogÃnese. A anÃlise qualitativa de metabÃlitos secundÃrios nos exsudatos revelou a presenÃa de fenÃis, triterpenÃides, saponinas, flavonas, flavonÃis e xantonas em ambas as cultivares. Posteriormente, estes exsudatos foram dialisados em membranas de diÃlise com exclusÃo de 3,5 kDa e submetidos à dosagem de proteÃnas bioativas. As atividades hemaglutinante (609,52 UH/mgP), inibitÃrias de tripsina (4,81 mg tripsina inibida/mgP) e papaÃna (30,48 UI/mgP), proteolÃtica (1,52 UAPr/mgP.min) e &#946;-1,3-glucanÃsica (58,26 &#951;katGLU/mgP) foram maiores para a cultivar BRS-Pala. Jà a atividade peroxidÃsica (0,218 UAP/mgP.min) predominou na cultivar BRS-Macota, A avaliaÃÃo da atividade nematicida sobre ovos e juvenis de segundo estÃdio (J2), usando exsudatos dialisados, revelou que ambos os exsudatos sÃo capazes de inibir a eclosÃo de M. incognita, bem como a mobilidade dos juvenis desta espÃcie. Esta propriedade nematostÃtica se reflete na infectividade do parasita, reduzida pelo tratamento com proteÃnas exsudadas na concentraÃÃo de 0,13 mg/mL. Os resultados reforÃam a ideia de que a exsudaÃÃo das sementes està relacionada à defesa constitutiva deste ÃrgÃo vegetal, sugerindo que proteÃnas presentes nos exsudatos podem promover proteÃÃo contra nematoides durante o processo germinativo. / Exudation is a defense mechanism presented by seeds, which release molecules to the soil during the germination process. These exudates, mainly composed by proteins and secondary metabolites, act interfering with the development of microorganisms. They represent a source of defense molecules with biotechnological potential to control soil-borne pathogens. In this context, soybean [Glycine max (L.) Merrill] stands as an ideal system in the study of plant-pathogen interaction due to its great economic value and the high content of seed proteins. The experimental activities presented in this thesis aimed to characterize the composition of seed exudates from two different soybean cultivars, which show different levels of performance in response to the root-knot nematode Meloidogyne incognita. Furthermore, the in vitro and in vivo effects of the seed exudates on this pathogen were evaluated. For this purpose, the exudates were obtained from soybean seeds (BRS-Pala:susceptible; BRS-Macota:resistant), soaked in 0.1 M sodium acetate, pH 5.0, during 18 hours. The gel-free proteomic analysis allowed identification of several defense-related proteins such as soybean agglutinin, Kunitz and Bowman-Birk trypsin inhibitors, and pathogenesis-related proteins. The qualitative analysis of secondary metabolites in the exudates also revealed the presence of phenols, triterpenoids, saponins, flavones, flavonols, and xanthones in both cultivars. The above exudates were dialyzed in 3.5 kDa cut-off membranes and assayed for bioactive proteins. The hemagglutinating (609.52 HU/mgP), trypsin (4.81 mg trypsin inhibited/mgP) and papain (30.48 IU/mgP) inhibitor, proteolytic (1.52 UAPr/mgP.min), and &#946;-1, 3-glucanase (58.26 &#951;katGLU/mgP) activities were higher for BRS-Pala. Otherwise, the peroxidase activity (0.218 UAP/mgP.min) predominated in BRS-Macota. The evaluation of anti-nematode activity against eggs and second stage juveniles (J2) revealed that both exudates were able to inhibit the hatching of M. incognita eggs as well as the J2 mobility. This nematostatic property is reflected in the infectivity of the parasite, reduced by the exuded protein at 0.13 mg/mL concentration. The results reinforce the idea that the exudation is related to the constitutive defense of the seeds, suggesting that the proteins present in the exudates can contribute to the protection against nematodes and possibly other plant enemies during the germination process.

No description available.

Submitted by Deyse Queiroz (deysequeirozz@hotmail.com) on 2018-05-28T18:07:04Z No. of bitstreams: 1 EDILENE SANTOS DA SILVA - DISSERTAÇÃO PPGSA PROFISSIONAL 2017..pdf: 2158872 bytes, checksum: 418ea38c71e65c65b9193ce57c792957 (MD5) / Made available in DSpace on 2018-05-28T18:07:04Z (GMT). No. of bitstreams: 1 EDILENE SANTOS DA SILVA - DISSERTAÇÃO PPGSA PROFISSIONAL 2017..pdf: 2158872 bytes, checksum: 418ea38c71e65c65b9193ce57c792957 (MD5) Previous issue date: 2017 / A jaca (Artocarpus heterophyllus. Lam) pertence à família das Moraceae, ao gênero Artocarpus e é originária da Ásia. O tamanho dos frutos associado à exsudação do látex e o seu aroma característico acentuado, tem sido fatores limitantes quanto ao seu consumo. O objetivo do presente estudo foi avaliar a qualidade da jaca minimamente processada e acondicionar em diferentes tipos de embalagens, sob temperatura de 3°C durante 12 dias. O experimento foi desenvolvido no Laboratório de Tecnologia de Produtos de Origem Vegetal do Centro de Ciências e Tecnologia Agroalimentar da Universidade Federal de Campina Grande, utilizando um delineamento experimental inteiramente casualizado em esquema fatorial 4 x 7 (4 tipos de embalagens e 7 intervalos de tempo), com 3 repetições totalizando 84 tratamentos. As embalagens usadas foram: polipropileno (PP), politereftalato de etileno (PET), poliestireno expandido recobertas com filme de cloreto de polivinila (PVC) e saco plástico de polipropileno biorientado (BOOP). Foram realizadas analises físico-química e de compostos bioativos da polpa. Os dados foram submetidos a análise de variância e regressões polinomiais. Foi significativo do tempo de armazenamento e dos tipos de embalagens. Houve acréscimos significativo em relação tempo e entre tipos de embalagem para as variáveis físico-químicas: Perda de Massa, Sólidos Solúveis, Acidez Titulável e pH. Os compostos bioativos: Clorofila, Carotenoides, Flavonoides e Antocianinas aumentaram com o tempo de armazenamento e diferiram com o tipo de embalagem. Os níveis de Ácido ascórbico foram reduzidos de forma significativa e os Compostos fenólicos totais sofreram também reduções com a evolução da maturação dos frutos. / The jaca (Artocarpus heterophyllus, Lam) and originated from Asia belongs to the Moraceae family, and Artocarpus genre. The size of the fruits associated to the latex exudation and its marked aroma characteristic has been limiting factors in its consumption. The had as of the objective to evaluate the quality of the processed jackfruit and to pack in different types of packages under temperature of 3° during 12 days. The experiment was developed in the Laboratory of Technology of Vegetable Sources at the Center of Sciences and Agrifood Technology of the Federal University of Campina Grande, using a completely randomized experimental design in a factorial scheme 4 x 7 (4 storage bags nature and 7 time intervals) with 3 replicates totalizing 84 treatments. Polypropylene (PP), polyethylene terephthalate (PET), expanded polystyrene coated with polyvinyl chloride film (PVC) and bioriented polypropylene plastic bag (BOOP) were used as packing materials during seven processing periods. Physical and chemical analyzes of the bioactive pulp compounds were performed. Data was submitted to analysis of variance and regressions. Was significant effect of the storage time and types of packages. The physic chemical variables mass loss, soluble solids, titratable acidity and pH were significantly influenced by the processing time and types of packaging increasing these with the time of processing. The bioactive compounds Chlorophyll, Carotenoids, Flavonoids and Anthocyanins also were affected significantly with the time of storage and type of packaging, increasing these with the time of processing. Ascorbic acid levels and total phenolic compounds were reduced with the evolution of fruit maturation.

Some plant-beneficial bacteria with biopesticide potential produce antimicrobial compounds that are tightly involved in multitrophic interactions occurring in the phytosphere among which antagonism toward a diverse range of phytopathogens. However, there is a crucial need for an accurate assessment of antibiotic production rate in this environment colonized by these bacteria. In this context, we conducted the present thesis work with the scope to better understand how two different Bacillus genus strains produce lipopeptides in the rhizosphere of plants. In the first part, one of the strains (B. amyloliquefaciens S499) was selected out of other isolates for its technological traits and in vitro inhibition growth activity of plant pathogenic fungi. We further demonstrated its biocontrol potential in tomato open-field experiments where plantings have been devastated by a local fungus preliminary identified as Fusarium semitectum. In a second part, we combined two mass spectrometry-based approaches (electrospray ionization and imaging) to analyze the pattern of surfactin, iturin and fengycin lipopeptide families produced in planta by strain S499. Our results show that rhizosphere conditions are conducive for surfactin synthesis but not for other types of lipopeptides and that the lipopeptide pattern can be markedly influenced by nutritional factors, biofilm formation and oxygen availability. In a last part, surfactin gene expression (srfA) level was evaluated in situ on tomato root using the reporter gene (LacZ) inserted in B. subtilis strain BGS3. Results showed effective expression of srfA and production of surfactin in biologically important level quantities upon establishment of bacterial population on roots. Our results also demonstrate that BGS3 developing in colonies, efficiently utilizes the main substrates from plant exudates to produce surfactins. The production may also be favored in bacteria growing slowly in the rhizosphere. Globally, this work contributes to better appreciate the impact of some environmental factors on the in situ biosynthesis of lipopeptides by strains of Bacillus which is probably an essential step for improving the level and reliability of their efficacy as biological agents for the control of plant diseases.