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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Ácidos orgânicos e solubilização de metais pesados em solos tratados com lodo de esgoto / Organic acid and heavy metals solubilization in soils treated with sewage sludge

Altafin, Leticia 11 November 2005 (has links)
Em solos tratados com lodo de esgoto, a concentração de metais pesados em solução é baixa e a cinética de dissolução é lenta. Com isso, as reações de complexação que ocorrem na rizosfera passam a ser importantes para a fitodisponibilidade destes metais. Estudos recentes demonstraram que ácidos orgânicos liberados por raízes, como acético, cítrico, láctico, oxálico e tartárico, são importantes agentes complexantes e, conseqüentemente, fitodisponibilizadores de metais pesados. Soluções de ácidos acético, cítrico, lático, oxálico e tartárico, nas concentrações: 0,4; 0,6; 0,8 e 1,00 mol L-1 foram utilizadas para extrair Cd, Cu, Cr, Ni, Zn e Pb de amostras de um LATOSSOLO VERMELHO AMARELO Distrófico (LVAd) e de um LATOSSOLO VERMELHO Eutroférrico (LVef) tratados com doses de 0, 40 e 80 Mg ha-1 de lodo de esgoto. Nas mesmas amostras foram cultivadas plantas de arroz, pelo método de Neubauer. Os teores de metais pesados nas plantas, colhidas 18 dias após a germinação, foram correlacionados com os teores extraídos pelas diferentes soluções dos ácidos orgânicos. Os resultados mostraram que a fitodisponibilidade de Cu e Zn pode ser estimada por todos os ácidos estudados e em todas as concentrações. Os ácidos lático e tartárico, em concentrações de 0,4 até 1 mol L-1, apresentaram potencial para estimar a disponibilidade Ni, e o ácido oxálico, em todas as concentrações, para Cr. Com aplicação de doses de lodo de esgoto de até 80 Mg ha-1 (base seca) não é prevista a disponibilidade de Cd e Pb, por isso não foi possível avaliar a eficiência dos ácidos orgânicos na previsão da fitodisponibilidade desses elementos. / In soils treated with sewage sludge, heavy metals concentration in solution is low and solubilization kinetics is slow. So, soluble complex formation that occurs in the rhizosphere became to be important in plant availability of these metals. Recent studies showed that organic acids released by roots, like acetic, citric, lactic, oxalic and tartaric acids, are important agents of solubilization and consequently can change heavy metals availability. Solution of acetic, citric, lactic, oxalic and tartaric acids in concentrations: 0.4, 0.6, 0.8, and 1.0 mol L-1 were used to extract Cd, Cu, Cr, Ni, Pb and Zn of soil samples treated with sewage sludge, in levels of 0, 40 and 80 Mg ha-1. Soils samples were also used in a Neubauer essay with rice as test plant. Heavy metals concentrations in the plants harvested 18 days after the germination were correlated with metals quantities removed from the different organic acid solutions. The results showed that Cu and Zn plant availability can be evaluated with all tested acids in all tested concentrations. Lactic and tartaric acids, 0.4 to 1.0 mol L-1, can be used to evaluate availability of Ni and oxalic acid, in all concentrations, can be a Cr extractant. . In the treatment receiving 80 Mg ha-1 of sewage sludge the Cd and Pb were not available as a result it was not possible to determine the organic acids efficiency to evaluate the bioavailability of these elements.
2

Disponibilidade de nutrientes e metais pesados tóxicos em plantas medicinais cultivadas em solos de diferentes texturas e sob diferentes condições de adubação / Availability of nutrients and toxic heavy metals in medicinal plants cultivated in soils of different textures and under different conditions of fertilization

Moraes, Alice Jacobus de 30 June 2010 (has links)
Made available in DSpace on 2017-07-10T17:37:36Z (GMT). No. of bitstreams: 1 Alice_Jacobus_de_Moraes.pdf: 426955 bytes, checksum: b421fdc5146075e0878931a1c09c272e (MD5) Previous issue date: 2010-06-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The cultivation and use of medicinal plants has followed man s evolution through centuries. Since the earliest civilizations, plants were already used for different purposes, especially for eating and in the treatment of diseases. Many recent surveys are pointing to the knowledge of sustainable agronomic practices that can provide higher quality and utilization of the active principles of interest of medicinal plants aiming to provide, for example, better environmental and nutritional conditions to plants. The aim of this study was to determine nutrient availability and content of heavy metals in two species of medicinal plants, Ocimun basillicum (Basil) and Calendula officinalis (Marigold), when subjected to different treatments with organic fertilization and conventional fertilization in different soil textures (sandy and clayey). For this, two similar experiments were conducted with each of the two species chosen in which the treatments were arranged in factorial scheme (2x2x3) arranged in a completely randomized design (CRD), being two soil textures (clayey and sandy), two forms of fertilizer (chemical and organic) and three levels of fertilization (unfertilized, the recommended dose and twice recommended dose) totalizing 12 treatments with four replications. The experiment conducted with basil plants, It was concluded that the clay soil favored the availability of P, K, Ca, Cu, Zn, Fe, Cd e Pb; the sandy soil favored the availability of N, Mn e Cr. The organic fertilization provided higher levels of N, P, Mg e Zn, while chemical fertilizer showed the presence of toxic heavy metals (Cd e Pb) in the sources of NPK used. The experiment conducted with marigold plants,the results showed that clayey soil favored the availability of N P, K, Mg, Cu, Zn and Fe; the sandy soil favored the availability of Ca, Mn, Pb and Cr. The organic fertilization provided higher levels of P and Fe, while the leaf tissue of marigold plants fertilized with chemical fertilizer showed higher concentrations of K and Mn. Marigold plants grown in clay soil were higher and had the highest average of dry volume and fresh volume.The results obtained with both experiments showed that the use of fertilizer improved the availability of heavy metals in the tissue of medicinal plants. The clay soil and organic fertilization favored the increase of CTC in the soil and the availability of nutrients that are essential to plants in general / O cultivo e a utilização de plantas medicinais tem acompanhado a evolução do homem através dos séculos. Muitas pesquisas recentes estão voltadas para o conhecimento de práticas agronômicas sustentáveis que possam proporcionar maior qualidade e aproveitamento dos princípios ativos de interesse das plantas medicinais, objetivando oferecer, por exemplo, melhores condições ambientais e nutricionais às plantas. O objetivo deste trabalho foi determinar a disponibilidade de nutrientes e o teor de metais pesados presentes em duas espécies de plantas medicinais, Ocimun basillicum (manjericão) e Calendula Officinalis (calêndula), quando submetidas a diferentes tratamentos com adubação orgânica e adubação convencional em solos de diferentes texturas (arenosa e argilosa). Para tanto, foram realizados dois experimentos semelhantes com cada uma das duas espécies escolhidas nos quais os tratamentos foram arranjados em esquema fatorial (2x2x3) dispostos em delineamento experimental inteiramente casualizado (DIC), sendo duas texturas de solo, (argilosa e arenosa), duas formas de adubação (química e orgânica) e três doses de adubação (sem adubação, dose recomendada e o dobro da dose recomendada) totalizando 12 tratamentos com quatro repetições. Com o experimento realizado com plantas de manjericão, pôde-se concluir que os solos argilosos favoreceram a disponibilidade de P, K, Ca, Cu, Zn, Fe, Cd e Pb; os solos de textura arenosa favoreceram a disponibilidade de N, Mn e Cr. A adubação orgânica disponibilizou maiores teores de N, P, Mg e Zn, enquanto a adubação química evidenciou a presença de metais pesados tóxicos (Cd e Pb) nas fontes de NPK utilizadas. No experimento realizado com plantas de calêndula os resultados demonstraram que os solos argilosos favoreceram a disponibilidade de N P, K, Mg, Cu, Zn e Fe; os solos de textura arenosa favoreceram a disponibilidade de Ca, Mn, Pb e Cr. A adubação orgânica disponibilizou maiores teores de P e Fe, enquanto o tecido foliar de plantas de calêndula adubadas com adubação química apresentaram concentrações maiores de K e Mn. As plantas de calêndula cultivadas em solo de textura argilosa apresentaram maior altura e maiores médias de massa seca e massa fresca. Os resultados obtidos nos dois experimentos demonstraram que a adubação química favoreceu a disponibilidade de metais pesados tóxicos no tecido vegetal de plantas medicinais. O solo de textura argilosa e a adubação orgânica favoreceram o aumento da CTC no solo e a disponibilidade de nutrientes que são essenciais às plantas em geral
3

Ácidos orgânicos e solubilização de metais pesados em solos tratados com lodo de esgoto / Organic acid and heavy metals solubilization in soils treated with sewage sludge

Leticia Altafin 11 November 2005 (has links)
Em solos tratados com lodo de esgoto, a concentração de metais pesados em solução é baixa e a cinética de dissolução é lenta. Com isso, as reações de complexação que ocorrem na rizosfera passam a ser importantes para a fitodisponibilidade destes metais. Estudos recentes demonstraram que ácidos orgânicos liberados por raízes, como acético, cítrico, láctico, oxálico e tartárico, são importantes agentes complexantes e, conseqüentemente, fitodisponibilizadores de metais pesados. Soluções de ácidos acético, cítrico, lático, oxálico e tartárico, nas concentrações: 0,4; 0,6; 0,8 e 1,00 mol L-1 foram utilizadas para extrair Cd, Cu, Cr, Ni, Zn e Pb de amostras de um LATOSSOLO VERMELHO AMARELO Distrófico (LVAd) e de um LATOSSOLO VERMELHO Eutroférrico (LVef) tratados com doses de 0, 40 e 80 Mg ha-1 de lodo de esgoto. Nas mesmas amostras foram cultivadas plantas de arroz, pelo método de Neubauer. Os teores de metais pesados nas plantas, colhidas 18 dias após a germinação, foram correlacionados com os teores extraídos pelas diferentes soluções dos ácidos orgânicos. Os resultados mostraram que a fitodisponibilidade de Cu e Zn pode ser estimada por todos os ácidos estudados e em todas as concentrações. Os ácidos lático e tartárico, em concentrações de 0,4 até 1 mol L-1, apresentaram potencial para estimar a disponibilidade Ni, e o ácido oxálico, em todas as concentrações, para Cr. Com aplicação de doses de lodo de esgoto de até 80 Mg ha-1 (base seca) não é prevista a disponibilidade de Cd e Pb, por isso não foi possível avaliar a eficiência dos ácidos orgânicos na previsão da fitodisponibilidade desses elementos. / In soils treated with sewage sludge, heavy metals concentration in solution is low and solubilization kinetics is slow. So, soluble complex formation that occurs in the rhizosphere became to be important in plant availability of these metals. Recent studies showed that organic acids released by roots, like acetic, citric, lactic, oxalic and tartaric acids, are important agents of solubilization and consequently can change heavy metals availability. Solution of acetic, citric, lactic, oxalic and tartaric acids in concentrations: 0.4, 0.6, 0.8, and 1.0 mol L-1 were used to extract Cd, Cu, Cr, Ni, Pb and Zn of soil samples treated with sewage sludge, in levels of 0, 40 and 80 Mg ha-1. Soils samples were also used in a Neubauer essay with rice as test plant. Heavy metals concentrations in the plants harvested 18 days after the germination were correlated with metals quantities removed from the different organic acid solutions. The results showed that Cu and Zn plant availability can be evaluated with all tested acids in all tested concentrations. Lactic and tartaric acids, 0.4 to 1.0 mol L-1, can be used to evaluate availability of Ni and oxalic acid, in all concentrations, can be a Cr extractant. . In the treatment receiving 80 Mg ha-1 of sewage sludge the Cd and Pb were not available as a result it was not possible to determine the organic acids efficiency to evaluate the bioavailability of these elements.
4

Effet de l’exsudation de citrate chez le lupin blanc sur la phytodisponibilité de l’uranium / Effect of citrate exudation in white lupine on uranium phytoavailability

Tailliez, Antoine 08 July 2013 (has links)
L’étude proposée s’inscrit dans un contexte de contamination croissante de la pédosphère et fait le choix d’appréhender cette problématique via une approche centrée sur la rhizospère et sur les mécanismes gouvernant son évolution. Ces travaux s'intéressent à la relation entre l’uranium – un métal naturel ubiquiste non-essentiel – et le citrate – un acide organique de faible poids moléculaire exsudé par certaines espèces végétales poussant sur un milieu pauvre en phosphore. Parmi ces espèces particulières le lupin blanc (Lupinus albus) fait office de plante modèle. Un sol naturellement riche en uranium prélevé à l’affleurement d’une veine de pechblende a été étudié. L’objectif du travail a été de savoir si l’activité racinaire est suffisante pour provoquer la remobilisation de l’uranium dans la solution du sol et favoriser son transfert. Le système sol/plante a été étudié sur rhizotest et de manière découplée en hydroponie et en réacteurs fermés. Il a été démontré que la présence d’uranium dans un milieu contrôlé (hydroponie) stimule l’exsudation de citrate chez les lupins blancs qui ne sont pas carencés en phosphore et que cette exsudation de citrate favorise la solubilisation de l’uranium dans la solution du sol en réacteurs fermés. Ces résultats ont été confirmés par les observations faites sur rhizotest même si les valeurs obtenues dans ce cas étaient plus nuancées. Ceci justifie les approches utilisées et met en évidence leur complémentarité. Les résultats obtenus ont également permis d’apporter des informations concernant la toxicité de l’uranium, son internalisation dans les cellules racinaires ainsi que sur son transfert des racines aux parties aériennes. / The present study is related to the context of pedosphere contamination increasing and chose to consider this issue through a focus on rhizosphere and mechanisms that govern its evolution. This work is oriented on the relation between uranium – a non-essential ubiquitous metal – and citrate – a low molecular weight organic acid exudated by specific species when grown on a phosphorus-deficient environment. Among these particular species white lupine (Lupinus albus) is considered as a model species. Furthermore, a natural soil containing huge amounts of uranium has been collected at the outcrop of a pitchblende vein and used during some experiments. The main aim of this PhD thesis was to determine if the root activity of white lupine is sufficient to cause the remobilization of uranium into soil solution and so to promote the transfer of this contaminant to the plant. The soil/plant system has been studied with rhizotests and by combining datas obtained with hydroponics experiments and batches tests. It has been demonstrated that the presence of uranium in a controlled growth medium (hydropony) stimulates citrate exudation in P-sufficient white lupine. More, this citrate exudation enhances uranium solubilization in soil solution in batches. These results have been confirmed by observations on rhizotest even if the values in this case were more nuanced. This justifies the employed approaches and highlights their coherence and complementarity. The results also allowed to provide additional information concerning uranium toxicity, its internalization in root cells as well as its transfer from roots to aerial parts.
5

Bioconcentration and desorption kinetic of potentially toxic elements in soils cultivated with horticultural crops in organic and conventional systems / Bioconcentração e cinética de dessorção de elementos potencialmente tóxicos em solos hortícolas sob sistemas orgânico e convencional

Araujo, Eloá Moura 19 February 2018 (has links)
Potentially toxic elements (PTEs) can be absorbed and accumulated in vegetables organ and tissues, and this is an important channel through which PTEs can enter into the food chain. Soil management may interfere in the behavior of PTEs in the system. So, the study of the dynamics of elements in the soil is fundamental to a better understanding of factors that influence soil-plant transfer. In the state of Pernambuco, Brazil, the production of vegetables is mainly concentrated in small or medium organic and conventional farms located in the Agreste and Sao Francisco regions. Our aims in this research were: i) to determine the contents of PTEs in soil and in vegetables produced under conventional and organic systems in garden soils of Pernambuco; ii) to investigate the forms of the PTEs and their uptake by the vegetables based on different soil-plant transfer factors; iii) to use the calculated transfer factors to assess the human risk exposure; iv) to assess the effect of aging and organic matter (OM) on copper (Cu) desorption in garden soils; v) to determine if manure application to soils increases water soluble Cu concentrations; and vi) to verify the efficiency of machine learning techniques in the classification of vegetables produced under organic and conventional systems. Acid and complexing solutions were employed to extract total contents of PTEs in plants and to extract pseudototal, reactive and bioavailable fractions of the PTEs in soils. Soil-plant transfer factors and human risk assessment were calculated based on the determined levels of PTEs. Kinetic assays were developed using rates of organic composts added to Cu-spiked soils to model the Cu desorption. Water extractable Cu and dissolved organic carbon (DOC) were extracted from soils amended with dairy manure, and the Cu-DOC interactions were studied using spectroscopic techniques. Lettuce (Lactuca sativa) leaves had the highest capacity to accumulate PTEs; conventional system promoted higher PTEs values in soils and plants than the organic production; regardless of the scenario, children and adults in contact to vegetables cropped in organic system have a lower health risk than individuals exposed to lettuce leaves conventionally produced. The addition of OM promoted greater Cu desorption, while aging lead to a reduction in the Cu release. The Fouriertransform infrared spectroscopy spectra showed increase in the presence of aliphatic and carboxylic groups in the extracts from the manure-amended soils. Carboxylic acid functional groups on the DOC formed strong bonds with Cu, which can promote Cu transport as dissolved Cu-organic complexes in the soil profile. The Support Vector Machine had an accuracy over 90% to classify the vegetables in the two groups (organic and conventional); and this high assertiveness rate highlights the potential of using elemental quantification and algorithms as support techniques in the process of authenticity and inspection of organic products. / Elementos potencialmente toxicos (EPTs) podem estar biodisponiveis para serem absorvidos e acumulados nos tecidos e orgaos vegetais, sendo esta uma importante rota de entrada de EPTs na cadeia alimentar. O manejo do solo pode interferir no comportamento dos EPTs no sistema. Desta forma, o estudo da dinamica desses elementos no solo e fundamental para melhor entendimento dos fatores que influenciam a transferencia solo-planta. No estado de Pernambuco, a producao de hortalicas se concentra em intensos cultivos organicos e convencionais localizados em pequenas ou medias propriedades, principalmente na regiao Agreste e Sao Francisco. Nossos objetivos neste trabalho foram: i) determinar os teores de EPTs no solo e nas hortalicas produzidas em sistemas convencionais e organicos em hortas de Pernambuco; ii) investigar as formas de EPTs e sua absorcao pelas hortalicas com base em diferentes fatores de transferencia solo-planta; iii) usar os fatores de transferencia calculados para investigar o risco de exposicao aos humanos; iv) estudar o efeito do tempo e da materia organica (MO) na dessorcao de cobre (Cu) em solos de horta; v) determinar se a aplicacao de esterco aumenta a concentracao de Cu soluvel em agua; e vi) verificar a eficiencia de tecnicas machine learning na classificacao de hortalicas produzidas em sistemas organicos e convencionais. Solucoes acidas e complexantes foram utilizadas para extrair os teores totais de EPTs nas plantas e os teores pseudototal, reativo e biodisponivel dos EPTs no solo. Fatores de transferencia solo-planta e avaliacao de risco humano foram calculados com base nos teores de EPTs. Estudos de cinetica foram desenvolvidos apos adicao de composto organico em solos contaminados com Cu para modelar a dessorcao de Cu. Cu soluvel em agua e carbono organico dissolvido (COD) foram extraidos de solos adubados com esterco, a interacao Cu-COD foi estudada usando tecnicas espectroscopicas. Folhas de alface (Lactuca sativa) apresentaram a maior capacidade de acumular EPTS; o sistema convencional promoveu maiores tores de EPTs nos solos e plantas do que o sistema organico; independentemente do cenario, criancas e adultos em contato com vegetais produzidos em sistema organico tem um menor risco do que os individuos que consomem folhas de alface convencionalmente produzidas. A adicao de MO promoveu maior dessorcao de Cu, enquanto o aumento no tempo de contato reduziu a liberacao de Cu. Os graficos da espectroscopia de infravermelho com transformada de Fourier mostraram um aumento na presenca de grupos funcionais alifaticos e carboxilicos nos extratos de solos adubados com esterco. Esses grupos funcionais no COD formam ligacoes fortes com Cu, o que promove o transporte do elemento na forma de complexos organicos dissolvidos no perfil do solo. O modelo Support Vector Machine apresentou acuracia superior a 90% na classificacao das hortalicas em dois grupos (organicas e convencionais); e a alta taxa de assertividade mostra o potencial do uso de quantificacao elementar e algoritmos como tecnicas auxiliares no processo de autenticidade de inspecao de produtos organicos.
6

Détermination, spéciation et biodisponibilité des éléments traces métalliques dans les sols contaminés et technosols / Determination, speciation and bioavailability study of trace metals in contaminated soils and technosols

Qasim, Bashar Hussein 17 November 2015 (has links)
Cette thèse a porté sur la détermination et l’étude écodynamique d’éléments traces métalliques sur des technosols fortement contaminés en métaux et metalloïdes en contexte de revégétalisation naturelle ou de phytoremédiation. Deux schémas d'extractions séquentielles ont été utilisés conjointement à des extractions sélectives en parallèle avec la détermination de la concentration totale dans les sols, de la concentration totale dissoute dans les eaux porales, du pool labile (sondes DGT) et des tests de germination avec des haricots nains pour étudier la spéciation, la mobilité et la phytodisponibilité de métaux et métalloïdes (Zn, Pb, Cd, As et Sb) pour les technosols de deux sites post-minier (La Petite Faye) et industriel (Mortagne-du-Nord). De plus de jeunes plants de P. euramericana Dorskamp ont été cultivés en rhizobox sur les technosols de Mortagne-du-Nord pour étudier l’effet rhizosphèrique sur la mobilité des métaux. Enfin l’effet de l’addition d’azote sous forme de nitrate et d’ammonium sur le comportement de ces métaux a été également étudié pour P. euramericana Dorskamp sur ces mêmes sols. Malgré les fortes concentrations totales en métaux et métalloïdes dans les sols du site de La Petite Faye, la mobilité de ces éléments potentiellement toxiques est limitée car associés à la fraction résiduelle. La phytodisponibilité est également limitée et corrélée avec le pool labile des technosols. La culture de P. euramericana Dorskamp a généré un effet rhizosphèrique caractérisé par une augmentation de la valeur du pH et la concentration de carbone organique dissout (COD) de la solution de sol ainsi qu’une diminution des concentrations totale dissoute des métaux (Zn, Pb et Cd) dans la solution de sol. L’addition d’azote sous forme de nitrate et d’ammonium a respectivement augmenté et diminué le pH de la solution de sol et dans le cas de l’ammonium a augmenté également le COD et stabilisé les métaux dans la rhizosphère par rapport aux sols de contrôle. / This thesis dealt with the determination and study of the ecodynamics of trace metals in technosols highly contaminated in metals and metalloids in the context of natural revegetalisation or phytoremediation. Two sequential extraction schemes were used jointly with selective extractions in parallel with the determination of the total metals concentration in soils, the total dissolved metals concentration in the soil pore water, the metals labile pool (DGT) and germination tests with dwarf beans to investigate the speciation, mobility and phytoavailability of (Zn, Pb, Cd, As and Sb) for technosols of two post-mining (La Petite Faye) and industrial (Mortagne du Nord) sites. Additionally, young plants of P. euramericana Dorskamp were cultivated in rhizobox on Mortagne du Nord technosols to investigate the rhizospheric effect on the mobility of metals. Moreover, the effect of nitrogen addition under nitrate and ammonium on the behavior of these metals has been investigated for P. euramericana Dorskamp for the same soils. Despite the high total metals and metalloids concentration in the La Petite Faye soils, the mobility of these potentially toxic elements is limited because of their association with the residual fraction. The phytoavailability is also limited and correlated with the labile pool of technosols. The culture of P. euramericana Dorskamp generated a rhizospheric effect characterized by an increase of the pH and concentration of dissolved organic carbon (DOC) in the soil pore water and a decrease in the total dissolved concentration of metals (Zn, Pb et Cd) in the soil pore water. The addition of nitrogen under nitrate or ammonium respectively increased and decreased the soil pore water pH and in the case of ammonium the DOC also increased and stabilized metals in the rhizosphere in comparison to control soils.
7

Bioconcentration and desorption kinetic of potentially toxic elements in soils cultivated with horticultural crops in organic and conventional systems / Bioconcentração e cinética de dessorção de elementos potencialmente tóxicos em solos hortícolas sob sistemas orgânico e convencional

Eloá Moura Araujo 19 February 2018 (has links)
Potentially toxic elements (PTEs) can be absorbed and accumulated in vegetables organ and tissues, and this is an important channel through which PTEs can enter into the food chain. Soil management may interfere in the behavior of PTEs in the system. So, the study of the dynamics of elements in the soil is fundamental to a better understanding of factors that influence soil-plant transfer. In the state of Pernambuco, Brazil, the production of vegetables is mainly concentrated in small or medium organic and conventional farms located in the Agreste and Sao Francisco regions. Our aims in this research were: i) to determine the contents of PTEs in soil and in vegetables produced under conventional and organic systems in garden soils of Pernambuco; ii) to investigate the forms of the PTEs and their uptake by the vegetables based on different soil-plant transfer factors; iii) to use the calculated transfer factors to assess the human risk exposure; iv) to assess the effect of aging and organic matter (OM) on copper (Cu) desorption in garden soils; v) to determine if manure application to soils increases water soluble Cu concentrations; and vi) to verify the efficiency of machine learning techniques in the classification of vegetables produced under organic and conventional systems. Acid and complexing solutions were employed to extract total contents of PTEs in plants and to extract pseudototal, reactive and bioavailable fractions of the PTEs in soils. Soil-plant transfer factors and human risk assessment were calculated based on the determined levels of PTEs. Kinetic assays were developed using rates of organic composts added to Cu-spiked soils to model the Cu desorption. Water extractable Cu and dissolved organic carbon (DOC) were extracted from soils amended with dairy manure, and the Cu-DOC interactions were studied using spectroscopic techniques. Lettuce (Lactuca sativa) leaves had the highest capacity to accumulate PTEs; conventional system promoted higher PTEs values in soils and plants than the organic production; regardless of the scenario, children and adults in contact to vegetables cropped in organic system have a lower health risk than individuals exposed to lettuce leaves conventionally produced. The addition of OM promoted greater Cu desorption, while aging lead to a reduction in the Cu release. The Fouriertransform infrared spectroscopy spectra showed increase in the presence of aliphatic and carboxylic groups in the extracts from the manure-amended soils. Carboxylic acid functional groups on the DOC formed strong bonds with Cu, which can promote Cu transport as dissolved Cu-organic complexes in the soil profile. The Support Vector Machine had an accuracy over 90% to classify the vegetables in the two groups (organic and conventional); and this high assertiveness rate highlights the potential of using elemental quantification and algorithms as support techniques in the process of authenticity and inspection of organic products. / Elementos potencialmente toxicos (EPTs) podem estar biodisponiveis para serem absorvidos e acumulados nos tecidos e orgaos vegetais, sendo esta uma importante rota de entrada de EPTs na cadeia alimentar. O manejo do solo pode interferir no comportamento dos EPTs no sistema. Desta forma, o estudo da dinamica desses elementos no solo e fundamental para melhor entendimento dos fatores que influenciam a transferencia solo-planta. No estado de Pernambuco, a producao de hortalicas se concentra em intensos cultivos organicos e convencionais localizados em pequenas ou medias propriedades, principalmente na regiao Agreste e Sao Francisco. Nossos objetivos neste trabalho foram: i) determinar os teores de EPTs no solo e nas hortalicas produzidas em sistemas convencionais e organicos em hortas de Pernambuco; ii) investigar as formas de EPTs e sua absorcao pelas hortalicas com base em diferentes fatores de transferencia solo-planta; iii) usar os fatores de transferencia calculados para investigar o risco de exposicao aos humanos; iv) estudar o efeito do tempo e da materia organica (MO) na dessorcao de cobre (Cu) em solos de horta; v) determinar se a aplicacao de esterco aumenta a concentracao de Cu soluvel em agua; e vi) verificar a eficiencia de tecnicas machine learning na classificacao de hortalicas produzidas em sistemas organicos e convencionais. Solucoes acidas e complexantes foram utilizadas para extrair os teores totais de EPTs nas plantas e os teores pseudototal, reativo e biodisponivel dos EPTs no solo. Fatores de transferencia solo-planta e avaliacao de risco humano foram calculados com base nos teores de EPTs. Estudos de cinetica foram desenvolvidos apos adicao de composto organico em solos contaminados com Cu para modelar a dessorcao de Cu. Cu soluvel em agua e carbono organico dissolvido (COD) foram extraidos de solos adubados com esterco, a interacao Cu-COD foi estudada usando tecnicas espectroscopicas. Folhas de alface (Lactuca sativa) apresentaram a maior capacidade de acumular EPTS; o sistema convencional promoveu maiores tores de EPTs nos solos e plantas do que o sistema organico; independentemente do cenario, criancas e adultos em contato com vegetais produzidos em sistema organico tem um menor risco do que os individuos que consomem folhas de alface convencionalmente produzidas. A adicao de MO promoveu maior dessorcao de Cu, enquanto o aumento no tempo de contato reduziu a liberacao de Cu. Os graficos da espectroscopia de infravermelho com transformada de Fourier mostraram um aumento na presenca de grupos funcionais alifaticos e carboxilicos nos extratos de solos adubados com esterco. Esses grupos funcionais no COD formam ligacoes fortes com Cu, o que promove o transporte do elemento na forma de complexos organicos dissolvidos no perfil do solo. O modelo Support Vector Machine apresentou acuracia superior a 90% na classificacao das hortalicas em dois grupos (organicas e convencionais); e a alta taxa de assertividade mostra o potencial do uso de quantificacao elementar e algoritmos como tecnicas auxiliares no processo de autenticidade de inspecao de produtos organicos.
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Fitodisponibilidade de metais, caracterização nutricional, constituição química, avaliação da atividade antioxidante e antibacteriana do óleo essencial extraído das folhas da Cinnamomum zeylanicum Breyn / Phytoavailability of metals, nutritional characterization, chemistry constitution, evaluation of the antioxidant and antibacterial activity of essential oil extracted from cinnamomum zeylanicum breyn s leaves.

Dias, Vera Lúcia Neves 28 October 2009 (has links)
Made available in DSpace on 2015-05-14T13:21:36Z (GMT). No. of bitstreams: 1 parte2.pdf: 1894746 bytes, checksum: ed814516402796b5f39625ca8197ed3a (MD5) Previous issue date: 2009-10-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The use of plants to medicine aims is an ancient practice. It s estimated that most of the plants used in the popular medicine has not been studied about their chemical compounds, phamacological action and their actual therapeutic indications, without consider the plants that has not been still identified. The Cinnamomum (Lauraceae) gender is constituted by approximately 350 species, many of them producers of essential oil. The Cinnamon has many aims, being used in the agriculture, to control nematodes, fungicide, in the urban forestation, cosmetics, cookery and in the medicine. This study had as aim evaluate: the phytoavailability of metals, nutritional characterization, chemistry constitution, evaluation of the antioxidant and antibacterial activity of essential oil extracted from Cinnamomum zeylanicum Breyn s leaves. The cinnamon s leaves initially were dried in room temperature, after, ground to next extraction of essential oil. The extraction was carried out using the hydrodistillation method. The determination of nutritional contents of the cinnamon was in average: 59.59% humidity, 1.320% ashes, 3.730% protein, 3.030% rough fibre, 3.050% lipids, 29.100% starch and 32.310% carbohydrates. The results show an availability to Ni and Cu metals, as low and high concentration respectively, 0.0007mg/L and 367.800. The ethanoic extracts of the essential oil from cinnamon in many tested concentrations presented a potential antioxidant and were sensitive front to the bacteria: Escherichia coli, Staphylococcus aureus, Serratia odorífera, Listeria monocytogenes, Pseudomonas aeruginosa and Proteus mirabilis. In the face of the deepening of this study, the mentioned oil can be presented as a potential antimicrobial agent, becomes a promising therapeutic alternative in a near future, especially to the poorest population. / A utilização de plantas para fins medicinais é uma prática antiga. Estima-se que a maioria das plantas usadas na medicina popular não foi estudada a respeito de seus componentes químicos, ações farmacológicas e suas reais indicações terapêuticas, sem considerar as plantas cujas propriedades medicinais não foram identificadas. O gênero Cinnamomum (Lauraceae) é constituído por aproximadamente 350 espécies, muitas das quais produtoras de óleo essencial. A Canela tem várias finalidades, sendo utilizada na agricultura, para controle de nematóides, fungicida, na arborização urbana, nas indústrias de cosméticos, na culinária e na medicina popular. Este estudo teve como objetivo avaliar: a fitodisponibilidade de metais, a caracterização nutricional, a constituição química, a avaliação da atividade antioxidante e antibacteriana do óleo essencial extraído das folhas da Cinnamomum zeylanicum Breyn. As folhas da canela, inicialmente foram secas em temperatura ambiente, em seguida moídas para posterior extração do óleo essencial. A extração foi realizada utilizando-se o método de hidrodestilação. A determinação dos teores nutricionais da canela foi em média: 59,590% umidade, 1,320% cinzas,3,730 % proteína, 3,030 % fibra bruta, 3,050% lipídeos, 29,100% amido e 32,310% carboidratos. Os resultados demonstram uma disponibilidade para os metais Ni e Cu, como menor e maior concentração respectivamente, 0, 0007 mg/L e 367,800. Os extratos etanóicos do óleo essencial da canela em diversas concentrações testadas apresentaram um potencial antioxidante e foi sensível frente às bactérias: Escherichia coli, Staphylococcus aureus, Serratia odorífera, Listeria monocytogenes, Pseudomonas aeruginosa e Proteus mirabilis. Diante do aprofundamento deste estudo, o referido óleo pode ser apresentado como agente antimicrobiano em potencial, tornando-se uma alternativa terapêutica promissora em futuro próximo, sobretudo para a população mais carente.
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Phytoextraction du plomb par les Pélargoniums odorants : interactions sol-plante et mise en place d'outils pour en comprendre l'hyperaccumulation / Lead phytoextraction by scented Pelargonium cultivars : soil-plant interactions and tool development for understanding lead hyperaccumulation

Arshad, Muhammad 10 July 2009 (has links)
L'utilisation des plantes pour décontaminer les sols pollués par les métaux est une solution respectueuse de l'environnement. Mais le développement de cette technique à grande échelle est encore limité en raison de l'indisponibilité de plantes avec les caractéristiques souhaitées (hyperaccumulation, biomasse élevée et croissance rapide). Les objectifs de ce travail étaient d'évaluer le potentiel de plusieurs cultivars de Pélargonium odorants pour l'extraction du Pb au champ, étudier la disponibilité du plomb en relation avec l'activité rhizosphérique et développer un protocole de transformation génétique. Parmi les six cultivars de Pélargonium odorants testés au champ, trois : Attar of Roses, Clorinda et Atomic Snowflake ont accumulé plus de 1000 mg kg-1 Pb, avec une forte biomasse. Pendant les expérimentations en conditions contrôlées, Attar of roses (le cultivar hyperaccumulateur) acidifie sa rhizosphère et augmente la concentration en COD significativement plus par rapport Concolor Lace (le cultivar non hyperaccumulateur), sans doute en réponse à la pollution métallique. Les concentrations en plomb dans les deux cultivars sont corrélées avec l'extraction au CaCl2. Les analyses par EXAFS et ESEM-EDS ont montré que le plomb présent dans les racines était principalement sous forme de complexes organiques alors que les sulfates de plomb prédominent dans le sol. Parallèlement à ces essais, un protocole de transformation génétique a été mis au point en vue de mieux comprendre les processus biochimiques impliqués dans l'hyperaccumulation et la fonction des gènes, Le système de régénération optimisé se base sur la pré-culture d'explants sur un milieu contenant 10 μM TDZ + 1 mg L-1 de chacun de BAP et NAA suivie par l'enlèvement de TDZ du milieu de culture. La kanamycine et l'hygromycine se sont avérés être de bons marqueurs sélectifs pour le Pélargonium. Deux souches d'Agrobacterium, C58 et EHA105 contenant des vecteurs binaires avec des gènes marqueurs hpt et nptII ont été choisis pour des expériences de transformation. Ils ont également le gène codant uidA séquence du gène rapporteur. Après l'infection avec C58, 4 et 107 plantes enracinées sur hygromycine ont été obtenues pour Attar of Roses et Atomic Snowflake, respectivement. Parmi ces plantes enracinées, les quatre plantes d'Attar et 82 d'Atomic Snowflake ont exprimé le Gus dans les feuilles, pétioles, les tiges et les racines comme prévu avec une séquence sous contrôle du promoteur constitutif CaMV 35S. De 20 plantes qui expriment le Gus, 7 plantes se sont avérées être positives après criblage par PCR. Après infection par EHA105, 23 et 133 plantes enracinées ont été obtenues après sélection sur kanamycine, mais aucune n'a démontré d'activité GUS. Seule des expériences d'empreintes par Southern blotting permettront de corréler le nombre d'insertions et niveau de l'expression dans ces différents événements de transformation. / Metal removal from contaminated soils using plants can provide an environment friendly solution. However, its successful application on a large scale is still limited due to unavailability of plants with desired set of characteristics i.e. hyperaccumulation, high biomass and rapid growth. The objective of this work was to assess the potential of scented Pelargonium cultivars for lead (Pb) extraction under field conditions, plant induced rhizosphere changes, soil factors influencing availability of Pb and to develop an efficient genetic transformation protocol for the selected cultivars. Of the six scented Pelargonium cultivars field-tested, three cultivars (Attar of Roses, Clorinda and Atomic Snowflake) accumulated more than 1000 mg Pb kg-1 DW, with high biomass reaching up to 45 tons ha-1 y-1 dry matter. During assays in controlled conditions, Attar of roses (Pb hyperaccumulator) significantly acidified its rhizosphere and increased Dissolved Organic Carbon (DOC) concentration as compared to Concolor Lace (non-accumulator), probably due to enhanced exudation in response to the metal stress. Lead concentrations in both cultivars were best correlated with CaCl2 extracted Pb. Extended X-ray Absorption Fine Structure (EXAFS) and Environmental Scanning Electron Microscopy-Energy Dispersive x-ray Spectroscopy (ESEM-EDS) demonstrated that Pb was mainly complexed to organic acids within plant tissues whereas the dominant form in soil was PbSO4. Parallel to the soil-plant Pb transfer assays, a genetic transformation protocol was optimized in view of better understanding biochemical processes involved in lead hyperaccumulation and gene function, in the future. The best regeneration scheme was based on the pre-culture of explants on 10 μM TDZ (Thidiazuron) in addition to 1 mg L-1 each of N6-benzylaminopurine (BAP) and α- naphthaleneacetic acid (NAA), followed by removal of TDZ from the culture medium. Kanamycin and hygromycin proved to be efficient selectable markers for genetic transformation. Two Agrobacterium strains, C58 and EHA105 harboring binary vectors carrying the selectable marker genes hpt and nptII were chosen for transformation experiments. They also contained the uidA gene coding sequence as reporter gene. After infecting with C58, 4 and 107 rooted plants on hygromycin-containing medium were obtained for Attar and Atomic cultivars, respectively. The four Attar plants and 82 Atomic plants expressed Gus in leaves, petioles, stems and roots as expected with a sequence driven by the 35S constitutive promoter. Polymerase Chain Reaction (PCR) screening was performed on Gus positive plants and 2 and 20 plants of Attar and Atomic were screened as PCR positive, respectively. After infection with EHA105, 23 and 133 rooted plants were obtained on kanamycin selection medium but none of these expressed Gus. Southern hybridization patterns will enable to correlate gene copy numbers to expression levels in these different events. The optimized protocols could be used for understanding molecular mechanisms of Pb accumulation and improvement in phytoextraction technique.

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