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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.
31

Ensaios pré-clínicos e clínicos com óleo essencial de Cymbopogon citratus (DC) Stapf. para tratamento de pitiríase versicolor. / Pre-clinical and clinical studies with essential oil of Cymbopogon citratus (DC) Stapf. for the treatment of pityriasis versicolor.

Carmo, Egberto Santos 08 July 2011 (has links)
Made available in DSpace on 2015-05-14T12:59:24Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 2398230 bytes, checksum: 9828aa609716cfe62aedf2537fb49e27 (MD5) Previous issue date: 2011-07-08 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / The aim of this study was to evaluate the antifungal potential of essential oil of Cymbopogon citratus (DC) Stapf. against Malassezia spp. We determined the minimum inhibitory concentration-MIC of essential oil of C. citratus on different strains of Malassezia, possible mechanisms of action by the writings of ergosterol (50-250 mg/mL) and sorbitol (0.8 M), and acute toxicity tests in mice (2000 mg/kg orally) and skin irritation in rabbits (application of essential oil in MIC90). After the pre-clinical tests were carried out clinical trials of phase I and II with shampoo, creamy lotion containing essential oil of C. citratus, respectively, in subjects healthy and with pityriasis versicolor. There was this work that the pityriasis versicolor reaches men and women alike, regardless of color and age, and the region of the posterior and anterior trunk the most affected. And the fungal species most frequently isolated were M. sympodialis and M. furfur. In preclinical evaluation in vitro antifungal activity of essential oil of C. citratus there was an MIC90 of 1.25 μL/mL. With the addition of ergosterol, the MIC increased about fourfold, suggesting a possible action of this oil on the fungal membrane. In pre-clinical toxicity in vivo was found low toxicity of essential oil of C. citratus, especially at 1.25 μL/mL. In phase I clinical trial, no toxicological manifestations such as edema, erythema or eschar was observed, allowing the secure verification of the formulations in Phase II, which after 40 days of treatment there was mycological cure of 60% for the group treated with oil. All data collected demonstrate the use of essential oil of C. citratus, as another therapeutic option for treatment of pityriasis versicolor, but a randomized phase III to be developed to validate them. / O objetivo deste estudo foi avaliar o potencial antifúngico do óleo essencial de Cymbopogon citratus (DC) Stapf. contra Malassezia spp. Para tanto foram determinadas a concentração inibitória mínima- CIM do óleo essencial de C. citratus sobre diferentes cepas de Malassezia, possíveis mecanismos de ação através dos ensaios de ergosterol (50-250 μg/ml) e sorbitol (0,8 M), além de ensaios de toxicidade aguda em camundongos (2000 mg/Kg via oral) e irritação de pele em coelhos (aplicação do óleo essencial na CIM90). Após os testes pré-clínicos, realizaram-se ensaios clínicos de fase I e II com xampu e loção cremosa contendo o óleo essencial de C. citratus, respectivamente, em indivíduos sadios e com pitiríase versicolor. Observou-se neste trabalho que a pitiríase versicolor atinge indistintamente homens e mulheres, independente de cor e idade, sendo a região do tronco posterior e anterior as mais acometidas. E as espécies fúngicas isoladas com maior freqüência foram M. sympodialis e M. furfur. Na avaliação pré-clínica in vitro da atividade antifúngica do óleo essencial de C. citratus verificou-se uma CIM90 de 1,25 μL/mL. Com a adição de ergosterol, a CIM aumentou cerca de quatro vezes, sugerindo uma possível ação deste óleo sobre a membrana fúngica. Nos ensaios pré-clínicos de toxicidade in vivo verificou-se baixa toxicidade do óleo essencial de C. citratus, especialmente a 1,25 μL/mL. No estudo clínico de fase I, nenhuma manifestação toxicológica como edema, eritema ou escara foi observada, permitindo a verificação segura das formulações na fase II, na qual após 40 dias de tratamento verificou-se 60% de cura micológica para o grupo tratado com o óleo. Todos os dados levantados demonstram a utilização deste óleo essencial de C. citratus, como mais uma opção terapêutica para tratamento de pitiríase versicolor, porém um estudo randomizado de fase III precisa ser desenvolvido para validá-los.
32

Diversité fonctionnelle des systèmes de détoxication chez les champignons lignolytiques / Functionnal diversity of the detoxification system in wood-decaying fungi

Perrot, Thomas 26 September 2018 (has links)
Les champignons décomposeurs du bois jouent un rôle important dans le cycle du carbone en participant notamment au recyclage de la matière organique. Outre leur aptitude à minéraliser la biomasse lignocellulosique, ces organismes ont la capacité de dégrader des molécules potentiellement toxiques libérées lors de ce processus. Leur système de détoxication comprend différentes familles multigéniques dont les glutathion transférases. Ces enzymes ubiquitaires, sont regroupées en différentes classes dans le règne fongique, certaines d’entre elles étant étendues chez ces champignons. Dans ce contexte, l’objectif principal de cette thèse consistait à appréhender les fonctions des glutathion transférases de la classe Omega (GSTOs) étendue chez Trametes versicolor, un champignon de pourriture blanche. Une approche biochimique et structurale a été menée sur neuf protéines produites de façon recombinante. Dans un premier temps, une caractérisation enzymatique de ces isoformes a été réalisée à l’aide de substrats synthétiques montrant une similarité des propriétés catalytiques. Puis, à partir d’une banque de molécules pures et de mélanges complexes issus de différentes essences forestières, une méthode de screening à haut débit a permis d’identifier des ligands potentiels de ces enzymes. La résolution de la structure tridimensionnelle de trois isoformes a démontré l’état homodimérique de ces protéines et l’implication de deux sites de fixation dans la reconnaissance de ces ligands : le site H (présent dans chaque monomère) et le site L (à l’interface du dimère). Par exemple, l’isoforme TvGSTO3S est capable de fixer dans son site H plusieurs hydroxybenzophénones, mais également un flavonoïde, la dihydrowogonine. Dans ce dernier cas, cette interaction avec un ligand naturel issu d’extraits de bois de merisier a été démontré par une approche de cristallographie d’affinité. D’autre part, des expériences de co-cristallisation ont permis de détecter deux molécules d’un autre flavonoïde, la naringénine, dans le site L de l’isoforme TvGSTO6S. Enfin, une interaction spécifique impliquant les sites H et L de l’isoforme TvGSTO2S a été démontrée avec l’oxyresvératrol. L’analyse structurale a révélé que les deux configurations du stilbène étaient liées à la protéine : la configuration trans dans le site H et la configuration cis dans le site L. Ainsi, malgré une redondance fonctionnelle partielle, ces recherches ont démontré l’existence d’un spectre d’interactions spécifiques pour chaque isoforme testée. Le caractère étendu de la classe Omega indiquerait que ces enzymes seraient impliquées dans l’adaptation du champignon à son environnement. En effet, les ligands identifiés au cours de ces travaux suggèrent que les propriétés « ligandines » des TvGSTOs joueraient un rôle dans la détoxication des produits issus de dégradation du bois / Wood decaying fungi play an important role in the carbon cycle by participating in the recycling of organic matter. In addition to their ability to mineralize lignocellulosic biomass, these organisms have the ability to degrade potentially toxic molecules released during this process. Their detoxification system involves several multigenic families including glutathione transferases. These ubiquitous enzymes are grouped into several classes in the fungal kingdom, some of them are widespread in these fungi. In this context, the main objective of this thesis was to understand the functions of glutathione transferases of the Omega class (GSTOs) extended in Trametes versicolor, a white rot fungus. A biochemical and structural approach was led using nine recombinant proteins. Firstly, enzymatic characterization of these isoforms was performed using synthetic substrates, the obtained results demonstrating a similarity of catalytic properties. Then, using a library of pure molecules and another one of complex mixtures from different forest species, a high throughput screening method was applied to identify potential ligands for these enzymes. The resolution of the three-dimensional structure of three isoforms demonstrated the homodimeric state of these proteins and the involvement of two binding sites in the recognition of these ligands: the H site (present in each monomer) and the L site (at the dimer interface). For example, the isoform TvGSTO3S is able to bind several hydroxybenzophenones in its H site, but also a flavonoid, dihydrowogonin. In this case, this interaction with a natural ligand derived from wild-cherry tree extract was demonstrated by an affinity crystallography approach. On the other hand, co-crystallization experiments detected two molecules of another flavonoid, naringenin, in the L site of the isoform TvGSTO6S. Finally, a specific interaction involving the H and L sites of the isoform TvGSTO2S was demonstrated with oxyresveratrol. Structural analysis revealed that the presence of both configurations of the stilbene in the protein: the trans configuration in the H site and the cis configuration in the L site. Thus, despite partial functional redundancy, this research demonstrated the existence of a specific pattern of interactions for each tested isoform. The expansion of the Omega class could indicate that these enzymes are involved in the adaptation of the fungus in its environment. Indeed, the ligands identified during this work suggest that the "ligandin" properties of TvGSTOs play a role in detoxifying wood degradation products
33

Estudo da multiplicidade de formas de ß-glicosidases de Aspergillus versicolor / Study of ß-glycosidases from Aspergillus versicolor

Alexandre Favarin Somera 12 March 2008 (has links)
Este trabalho procurou avaliar algumas isozimas envolvidas com o processo de degradação de polissacarídeos da parede celular vegetal, encontradas em Aspergillus versicolor, fungo pertencente a um gênero onde a multiplicidade de componentes enzimáticos com a mesma atividade oscila de uma a três. Duas ß-xilosidases foram purificadas por meio de DEAE-celulose e precipitação com sulfato de amônia. Ambas mostraram-se enzimas que, quando deglicosiladas por PNGaseF, apresentam mesmos mapas trípticos. A glicosilação mostrou-se importante para a manifestação de diferenças bioquímicas relacionadas às interações com ambiente eletrolítico adjacente, visto as mudanças das curvas de pH e alterações de comportamento frente a sais de íons metálicos, tão bem como para a manutenção do funcionamento das enzimas. Também foi verificado que as diferentes formas glicosiladas periplásmicas são produzidas em meios distintos (xilana e xilose), cujos pH finais corresponderam aos pH das enzimas encontradas. Por meio de zimogramas, verificou-se que estas não eram produzidas de imediato, mas selecionadas ao longo do tempo de cultivo. Esta seleção foi inicialmente independente do pH, visto este, mesmo tamponado, ser corrigido pelo fungo, de modo a se apresentar, ao final de 48h, correlato com o da enzima selecionada. Exame cromatográfico em Concanavalina-A das enzimas deglicosiladas por EndoH mostraram que a oriunda de xilana tem aporte maior de ramificações biantenárias, que são ricas em galactose. Ambas apresentaram mapas trípticos iguais. A ß-xilosidase induzida por xilana apresentou proporções de manose, galactose e glucose iguais a 69,68 : 30,25 : 0,056 %, respectivamente, enquanto que ß-xilosidase induzida por xilose apresentou proporções iguais a 85,35 : 14,54 : 0,094%, respectivamente, resultado que corrobora com a resultado anterior. Duas ß-glucosidases de superfície micelial foram purificadas por meio de DEAE-Sephacel e DEAE-celulose. Ambas mostraram-se mais semelhantes entre si que as ß-xilosidases, e independentes de fonte de carbono ou pH. No entanto, apresentaram diferenças frente à inibição por celobiose (acentuada a partir de 10mM para ß-glucosidase I e 20mM para B-glucosidase II) e, embora sutis, a pH. Após serem submetidas a 45 ºC por 30min (temperatura que induziu segunda conformação estável) mostraram curvas de pH muito distintas, que foram eliminadas nas enzimas submetidas ao mesmo experimento após deglicosilação por PNGaseF. Ambas apresentaram mapas trípticos iguais. A ß-glucosidase I mostrou-se constituída de Man:Gal:Glu em proporções iguais a 78,36%:21,61%:0,033% do carboidrato total, respectivamente, e a ß-glucosidase II, Man:Gal:Glu iguais a 83,59%:16,38%:0,028%, respectivamente. Ambas também apresentaram sinergismo quando juntas. Sobre celobiose, foi verificado apenas em pH acima de 5.5. Sobre celooligossacarídeos, manifestou-se em pH 5,25. A ß-glucosidase I foi menos ativa que a ß-glucosidase II quando em ausência de glucose e celobiose na solução de reação inicial, situação na qual o contrário foi verdadeiro. O sinergismo foi drasticamente eliminado após deglicosilação por PNGaseF. Não se sabe se este resultado foi oriundo de mudanças cinéticas provocadas pela deglicosilação ou de uma possível eliminação de agregação anteriormente existente entre glicosiladas. O componente ß-glicosidásico extracelular foi purificado por meio de DEAE-Sephacel e Octyl-Sepharose, e se revelou um heteroagregado de fosfatase ácida com ß-glicosidase, que se mostrou estável e ativo em ampla gama de temperaturas e pH, com ótimos de 55ºC e 5,5, respectivamente. Entretanto, os perfis das curvas foram distintos entre as enzimas componentes. Somente concentrações superiores a 0,8mM de cloreto de cobalto apresentaram efeito desagregador, podendo ser empregado em conjunto com DEAE-celulose para purificação das enzimas isoladas. Quando separadas, fosfatase mostrou-se 260% mais ativa e ß-glicosidase, 50% menos ativa. Nesta condição, as faixas de pH se restringiram, acidificando-se, localizando-se entre pH 4,0 e 5,5. Aparentemente, a agregação reforça a atividade celobiásica. Fosfatase foi ativa sobre farelo de trigo e fitato de sódio e adsorveu fortemente em farelo de trigo. ß-glicosidase apresentou atividade sobre farelo de trigo, xilana e Avicel (liberando apenas glicose desta última), revelando-se enzima com atividade celobioidrolásica inespecífica, embora ávida por celobiose. As atividades foram determinadas como oriundas do mesmo sítio catalítico. ß-glicosidase não foi seqüestrada por farelo de trigo quando desagregada, resultado invertido quando reagregada. O seqüestro por farelo de trigo, aparentemente, deveu-se a interações entre sítio catalítico da fosfatase e substrato. / This study explored enzyme multiplicity on hemicelllulose and cellulose degrading systems. It first demonstrates the differences of PNGaseF deglycosylation and EndoH deglycosylation on forms of two ß-glicosidase activities present on surface of mycelia from Aspergillus versicolor grown on several carbon sources. Aspergillus versicolor produces ß-xylosidases with different biochemical properties and different degree of glycosylation, when grown on xylan or xylose. Were investigated the biochemical properties of these ß-xylosidases after deglycosylation. The purified enzymes were deglycosylated with endo-H or PNGase F. After this treatment both enzymes migrated faster in PAGE exhibiting the same Rf. On SDS-PAGE both enzymes showed similar migration. The optima temperature of xylan-induced and xylose-induced ß-xylosidases was 45 ºC and 40 ºC, respectively, and of 35 ºC after deglycosylation. The xylan-induced enzyme was more active at acidic pH than the xylose-induced enzyme. After deglycosylation the optimum pH of both enzymes was 6.0. The thermal resistance of the enzymes at 55 ºC showed a half-life of 15 min and 9 min for xylose-and xylan-induced enzymes, respectively. After deglycosylation both exhibited half-lives of 7.5. Native enzymes exhibited different response to ions, while deglycosylated enzymes exhibited identical sensitivity to ions. Limited proteolysis yielded coincident profiles in SDS-PAGE for both deglycosylated enzymes. All data suggest that the two A.versicolor ß-xylosidases share a common polypeptide core with differential glycosylation, apparently responsible for their biochemical and biophysical differences. Aspergillus versicolor also produced ß-glucosidases with different biochemical properties and different degree of glycosylation independently of carbon source. ß-Glucosidase I differed from ß-glucosidase II principally considering the amount and composition of carbohydrate, sensitivity to ions and pH. The purified enzymes shared the same tripitic maps and molecular masses after deglycosylations. All results showed that the biochemical differences observed for two enzymes were directly linked to PNGaseF- deglycosylation. Considering that Rfs, elution profiles on Con-A and residual glycosylation of both enzymes treated with EndoH or PNGaseF were the same, but differed on the mannose/galactose ratio, we inferred differences on proportion of hybrid-type/high-mannose-type glycans. The significance of this glycoform diversity was stressed in analysis of the action of mixture of both ß-glucosidases on celooligosoccharides and on cellobiose. This synergism was abolished after PNGaseF deglycosylation. These results are the first to show synergism between glycoforms of glycosil-hydrolases, representing a new class of synergistic type. The work also described a new form of aggregation between enzymes. Generally, ß-glycosidases are described as soluble components, attached to cell wall or free in the culture medium. This work verified that it could be extracelular adsorbed to wheat straw when aggregated with an acid phosphatase. The results strongly suggested that phosphatase is the component responsible for the process of adsorption on the substrate. The disaggregation was cobalt mediated, being not observed for another ions. The aggregation state has positive effects on glycosidase activity, extending pH ratio and increasing hydrolysis velocity. The opposite was found to phosphatase activity.
34

Évolution et adaptation des champignons saprophytes : les systèmes impliqués dans la dégradation du bois chez Trametes versicolor / Evolution and adaptation of saprophytic fungi : wood degrading systems in Trametes versicolor

Deroy, Aurélie 06 November 2015 (has links)
Le bois représente une des ressources en polymères les plus abondantes de l’écosystème terrestre. Les champignons dégradant la matière lignocellulosique jouent un rôle important dans le cycle du carbone. Ils présentent un fort intérêt au niveau biotechnologique en particulier pour la production d’enzymes. Parmi les champignons saprophytes, ceux de la classe des Agaricomycota sont particulièrement intéressants puisqu’ils possèdent la capacité de dégrader les différents composés du bois : cellulose, hémicelloloses et lignine. De plus, ces champignons ont développé un système de détoxication impliquant des enzymes telles que les glutathion transférases (GST). Celles-ci sont impliquées dans la dégradation de composés potentiellement toxiques générés lors de la dégradation du bois mais également la dégradation de xénobiotiques. L’étude des systèmes extracellulaires et intracellulaires de Trametes versicolor impliqués dans les processus de décomposition du bois, décrite dans ce manuscrit, avait pour objectif d’identifier les facteurs moléculaires impliqués dans l’adaptation des champignons à leur environnement. Les approches pluridiciplinaires mises en œuvre lors de cette thèse ont permis d’identifier une variabilité phénotypique intraspécifique chez une dizaine de souches de T. versicolor, cette variabilité semblant être liée à la nature de l’essence ligneuse d’origine de ces souches. De plus, les travaux réalisés sur les GSTs apparteant aux classes oméga et GHR ont contribué à améliorer nos connaissances sur l’implication de cette famille multigénique dans l’adaptation des champignons xylophages à leur mode de vie / Wood is one of the most abundant polymer resources of the Earth’s ecosystem. Wood decaying fungi play an important role in the carbon cycle. They have a strong interest in biotechnology level in particular for the production of enzymes. Among the saprophytic fungi, those of the class of agaricomycota are particularly studied since they possess the ability to degrade varous compounds from wood : cellulose, hemicelluloses dand lignin. In addition, these fungi have developed a detoxification system involving enzymes such as glutathione transferases (GST). These latter are involved in degradation of wood but also in the degradation of xenobiotics. In this manuscript, the study of extracellular and intracellular system from Trametes versicolor, involved in wood decay process is described, the main goal being to identify the molecular factors involved in adaptation of the to their environment. Multidisciplinary approaches used in this PhD led to identification of an intraspecific phenotypic variability among ten strains of T. versicolor, this variability appearing to be related to the tree species where these strains have been isolated. Moreover, the work done on GSTs belonging to GHR and omega classes have improved our knowledge of the involvement of this gene family in adaptating the wood decayers to thrit lifestyle
35

Diversité structurale des Glutathion Transférases fongiques des classes Oméga et Xi et identification de leurs ligands par des approches cristallographiques / Structural diversity of fungal Xi and Omega glutathione transferases and identification of their ligands by crystallographic approaches

Schwartz, Mathieu 25 September 2018 (has links)
La détoxication est un processus biochimique présent chez tous les organismes biologiques et qui leur permet d’assurer leur survie face aux xénobiotiques provenant de leur environnement. Les glutathion transférases (GST) représentent une large famille d’enzymes participant à la phase II de détoxication en conjuguant le glutathion au composé à éliminer. Par ailleurs, certaines GST ont un rôle non catalytique et assurent la séquestration ou le transport de molécules d’un compartiment cellulaire à un autre. Alors que l’activité catalytique des GST est étudiée depuis plusieurs décades, l’identification précise des molécules physiologiques ciblées par les GST reste un défi. Chez les organismes fongiques dégradeurs de bois, certaines classes de GST se sont multipliées au niveau génomique. Cette redondance serait le reflet de la diversité des molécules chimiques libérées lors de la dégradation du bois. Dans cette thèse, des approches biochimiques et structurales ont été employées pour caractériser onze isoformes de GST du basidiomycète Trametes versicolor. De plus, une approche utilisant des librairies de molécules a permis d’identifier une famille de ligands reconnus par ces GST : les polyphénols. Les modes d’interaction de ces ligands ont été décrits précisément à partir de la résolution de nombreuses structures cristallographiques. L’identification d’un flavonoïde à partir d’un extrait de bois de merisier (Prunus avium), arbre sur lequel croît T. versicolor, a été permise par une approche de cristallographie d’affinité. Ces données suggèrent que les GST d’organismes fongiques saprotrophes pourraient prendre en charge les polyphénols libérés lors de la décomposition du bois / The ubiquitous biochemical process that enables each organism to cope with xenobiotics from its environment and thus ensures its survival is called detoxification. Glutathione transferases (GSTs) form a large family of enzymes divided into several classes. These enzymes participate in the detoxification phase II by conjugating the tripeptide glutathione to the molecule to be eliminated. Moreover, some GSTs are involved in non-catalytic processes such as sequestration or transport of molecules from one cellular compartment to another. Studies dedicated to the catalytic activity of GSTs have been ongoing for decades, yet precise identification of molecules targeted by GSTs remains challenging. In wood-decaying organisms, some of the GST classes have expanded with an increase of the number of isoforms encoded at the genomic level. This redundancy would reflect the diversity of the small molecules released upon wood enzymatic degradation. Through this thesis work, biochemical and structural approaches were used in order to characterize eleven GST isoforms from the saprotrophic fungus Trametes versicolor. In addition, the use of libraries of molecules helped in identifying polyphenols as a family of ligands that bind these GSTs. The molecular interaction modes were described precisely based on the resolution of numerous crystal structures. The identification of a flavonoid from an extract of the wild-cherry tree (Prunus avium) on which T. versicolor grows, was enabled by using an affinity crystallography approach. These data suggest that fungal GSTs could interact with plant polyphenols released during wood degradation
36

Atividade forrageadora da vespa social Polistes versicolor (Olivier, 1791) (Hymenoptera, Vespidae) em plantio de eucalipto no município de Juiz de Fora, MG

Elisei, Thiago 15 February 2008 (has links)
Submitted by isabela.moljf@hotmail.com (isabela.moljf@hotmail.com) on 2017-05-10T10:53:52Z No. of bitstreams: 1 thiagoelisei.pdf: 782394 bytes, checksum: aefc93d2cbb07ead5cb33d14bcfd96a1 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-05-17T15:02:14Z (GMT) No. of bitstreams: 1 thiagoelisei.pdf: 782394 bytes, checksum: aefc93d2cbb07ead5cb33d14bcfd96a1 (MD5) / Made available in DSpace on 2017-05-17T15:02:14Z (GMT). No. of bitstreams: 1 thiagoelisei.pdf: 782394 bytes, checksum: aefc93d2cbb07ead5cb33d14bcfd96a1 (MD5) Previous issue date: 2008-02-15 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Na procura por recursos as vespas interagem com diversas espécies da fauna e flora do ambiente onde reside. A importância deste grupo como entomofauna associada à diversas espécies de plantas têm sido corroborada por estudos que evidenciam os visitantes dos nectários florais de diversas espécies de vegetais. Além disso, diversos autores trazem informações da ação de predação de vespas sociais em diversos grupos de invertebrados, utilizando a proteína animal provinda destas presas na alimentação de suas crias. Desta forma, o estudo do horário de forrageio, material forrageado e a transferências de colônias para outras áreas, utilizando a espécie Polistes versicolor como teste, objetivos deste estudo, podem evidenciar características da espécie que revelem seu potencial em planos de manejo que visam sua utilização como agente de controle de pragas do eucalipto. Além disso, as informações acerca do horário de atividade de forrageio da espécie estudada pode auxiliar táticas de manejo integrado envolvendo controle e biológico e químico. No período de janeiro a dezembro de 2007, foram realizadas 24 observações da atividade forrageadora de colônias de P. versicolor presentes em um eucaliptal, no município de Juiz de Fora, Minas Gerais, totalizando 240 horas de registros. Durante 10 horas de observação diária foram registradas, a cada 30 minutos, a luminosidade, velocidade do vento, umidade e temperatura do ar nas proximidades da colônia, além disso, foram registrados e qualificados, também a cada 30 minutos, os retornos das operárias, seguindo metodologia já aplicada no estudo comportamental de vespas sociais. No mesmo período foram transferidas 20 colônias de P. versicolor, em estágio de pós-emergência, retiradas de edificações humanas e transferidas para abrigos artificiais instalados na plantação de eucalipto estudada. A atividade forrageadora de P. versicolor iniciava por volta das sete horas e trinta minutos e se estendia até ás 18 horas. As vespas saiam em média por hora 9,62 ±16,67 (0-84) com um total de 1792 saídas nas 240 horas de observação, e retornaram também em média por hora, 9,76 ±18,14 (0-87) com um total de 1809 nas horas de observação. A atividade das colônias foi mais intensa no período compreendido entre as 10 horas e ás 15 horas. O teste de correlação de Spearman revelou que as saídas de operárias de P. versicolor foram estimuladas pelo aumento da luminosidade e temperatura do ar, e pela diminuição da umidade relativa do ar. O teste de regressão linear múltipla mostrou que a temperatura do ar é a variável que a mais influenciou a atividade forrageadora. Foram registrados 1809 retornos sendo que 51,63% foram com néctar; 6,85% água; 4,7% fibra vegetal; 19,40% improdutivos e 17,41% com presas. As operárias de P. versicolor predaram exclusivamente lagartas de lepidópteros, sendo estas a única fonte de proteína animal oferecidas aos imaturos que se desenvolviam na colônia. As 20 colônias P. versicolor transferidas no trabalho obtiveram 85% de sucesso, evento caracterizado pelo fato de após o estabelecimento da colônia no abrigo artificial, os indivíduos permaneceram no ninho. O presente estudo revelou que P. versicolor apresentou características que possibilitam seu uso em programas de manejo integrado de pragas empregando vespas como agentes de controle biológico. / On the development and maintenance of a social wasp colony, need to search and use environmental resources, as the water, used in the control of the temperature; vegetable fiber, utilized on the construction and repair of cells and comb; carbohydrate to feeding larvae and adults, obtained mainly in nectary and fruits; and animal protein, used to feeding larvae, proceeding, most of the time, to predation of caterpillar. On this way, the study of the forage schedule, material foraged and to transfers colonies to other areas, using the species Polistes versicolor as test, objectives of this study, can evidence characteristics of the species that reveal its potential in programs that aiming its use as agent control of eucalyptus plagues. On the period of January to December of 2007, were accomplished 24 observations of the P. versicolor foraging activity colonies were present in an eucaliptal, on the municipal district of Juiz de Fora, MINAS GERAIS, totalizing 240 hours. During 10 hours were registered, to every 30 minutes, intensity light, wind speed, air humidity and temperature on the colony proximities; also were registered and qualified, the workers' returns according to methodology proposal for Prezoto et al. (1994). On the same period, were transferred 20 P. versicolor colonies, in post-emergency, retreats of human constructions and transferred for artificial shelters installed in eucalyptus plantation. The P. versicolor foraging activity began about the seven hours and thirty minutes and it extended even 18 hours. The workers average of departures/hour were 9.62 ±16.67 (0-84) with a total of 1792 on 240 hours observation, and returns/hour 9.76 ±18.14 (0-87) with a total of 1809 on the observation hours. The colonies activity pick happened on the period understood between the 10 hours and even 15 hours. The Spearman correlation test revealed that the P. versicolor workers exits were stimulated by the increase of the light intensity and air temperature; and decrease of the humidity. The multivariate linear regression analysis showed that air temperature is the variable that most influence on the P. versicolor foraging activity. On this work was registered 1809 returns, being 51.63% were with nectar; 6.85% water; 4.7% vegetable fiber; 19.40% unproductive and 17.41% with preys. P. versicolor workers preying exclusively caterpillars, being this only animal protein offered to the immature ones that were developed in the colony. The 20 P. versicolor colonies used in the work was collected and transferred with 85% of success, due to the fact of after the establishment of the colony in the artificial shelter, the individuals stayed in the nest. The present study revealed that P. versicolor offered characteristics that make possible its use in programs of handling integrated plagues using wasps as agents of biological control.
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Estudo fitoquímico de Helietta puberula (Rutaceae), Simarouba versicolor (Simaroubaceae) e busca de um processo de microencapsulação de compostos ativos visando o controle de formigas cortadeiras. / PHYTOCHEMICAL INVESTIGATION OF Helietta puberula (RUTACEAE), Simarouba versicolor (SIMAROUBACEAE) AND SEARCH OF MICROENCAPSULATION TECHNICAL OF THE ACTIVES COMPOUNDS FOR THE CONTROL OF LEAF-CUTTING ANTS.

Simote, Simone Yasue 02 June 2006 (has links)
Made available in DSpace on 2016-06-02T20:34:04Z (GMT). No. of bitstreams: 1 TeseSYS.pdf: 12958851 bytes, checksum: b27e3b157a5ab30383540f9953fc104a (MD5) Previous issue date: 2006-06-02 / Universidade Federal de Minas Gerais / This work involved the bioassay-guided study of Helietta puberula (Rutaceae) e Simarouba versicolor (Simaroubaceae). The biossays were carried out with leaf-cutting ants Atta sexdens rubropilosa, antifungal activity against the symbiotic fungus Leucoagaricus gongylophorus and inhibition of the enzymatic activity of pectinases. The results obtained with extracts and fractions showed that the selected plants were promising source of compounds in the control against leafcutting ants. The phytochemical investigation of active extracts and fractions allowed the isolation of 31 compounds of differences types such as: steroids ( β- sitosterol, stigmasterol, sitostenone, stigmastenone, campestenone and 3 β-O-3 β- D-glucopyranosil sitosterol); triterpenes of the tirucalane type (22S,3 α- dihydroxytirucal-7,24-dien-23-one), esqualene (eurilene) and lupanic (lupeol and lupenone); quinoline alkaloids (N-metil-4-methoxy-2-quinolone), furoquinolinic alkaloids (dictamine, γ-fagarine, kokusaginine, maculine, flindersiamine), acridonic alkaloids (arborinine); canthinonic alkaloids (4,5- dimethoxycanthin-6-one and 5-methoxycanthin-6-one) and of the β-carboline types of alkaloids (7-hidroxy-ethyl β-carboline and 7-hidroxy-1,1 -propyonate of methyl β-carboline); flavonoids (flavone, isosakuranetine and 5,7,3 ,4 ,5 - pentamethoxyflavone); one stilbene (22); coumarins (7-hidroxycoumarin, 6,7- dimethoxycoumarin, 6-hydroxy-7,8-dimethoxycoumarin, 3 -(1 ,1 - dimethylalyl)-isoescopoletin, methylether-graveliferone); quassinoids (glaucarubolone and glaucarubinone) and two cinnamic acids derivatives (methyl 3,4,5-trimethoxycinnamate and geranyl 3,4-dimethoxycinnamate). Among these substances, furoquinoline and canthinonic alkaloids, flavone and the quassinoids were active against the L. gongylophorus fungus; inhibiting 100% of its grownth and also showed inhibition against leaf-cutting ants survivel biossay. The study of chitosan as matriz on the microencapsulation process; to the encapsulation of the bioactive compound, reduction of the mammalian toxicity, protection Humans and also the environment; showed very promising results, but more study is necessary mainly to reduce the size of the particle / Este trabalho apresenta o estudo fitoquímico de duas plantas: Helietta puberula (Rutaceae) e Simarouba versicolor (Simaroubaceae), biomonitorado através de ensaios em três modelos biológicos: formigas cortadeiras (Atta sexdens rubropilosa), seu fungo simbionte (Leucoagaricus gongylophorus) e enzimas pectinases. Os ensaios biológicos de extratos e frações mostraram que as plantas selecionadas são promissoras no controle de formigas cortadeiras. O estudo fitoquímico dos extratos e frações ativas levou a identificação de 34 substâncias de diferentes classes: esteróides (sitosterol, estigmasterol, sitostenona, estigmastenona, campestenona e 3 β-O-3 β-D-glucopiranosil sitosterol); triterpenos do tipo tirucalano (22S,3 α-diidroxitirucala-7,24-dien-23-ona); esqualeno (eurileno) e lupânico (lupeol e lupenona); alcalóides do tipo quinolônico (N-metil-4-metóxi- 2-quinolona, furoquinolínicos (dictamina, γ-fagarina, kokusaginina, maculina, flindersiamina), acridônico (arborinina); cantinônicos (4,5-dimetóxicantin-6-ona e 5-metóxicantin-6-ona) e do tipo β-carbonílicos (7-hidroxi-1-etil β-carbolina e 7-hidroxi-1,1 -propionato de metila β-carbolina); flavonóides (flavona, isosakuranetina e da 5,7,3 ,4 ,5 -pentametóxiflavona) e do estilbeno; de cumarinas (7-hidróxicumarina, 6,7-dimetóxicumarina, 6-hidróxi-7,8- dimetóxicumarina, 3 -(1 ,1 -dimetilalil)-isoescopoletina, metiletergraveliferona); quassinóides (glaucarubolona e glaucarubinona) e de dois derivados do ácido cinâmico (3,4,5-trimetoxicinamato de metila e 3,4- dimetoxicinamato de geranila). Dentre essas substâncias, os alcalóides do tipo furoquinolínicos e cantinônicos, a flavona e os quassinóides, apresentaram inibição de até 100% no crescimento do fungo L. gongylophorus e sobrevivência média de 7 dias num experimento de 23 dias nos ensaios com A. sexdens rubropilosa. O estudo da quitosana como matriz no processo de microencapsulação, visando a estabilidade do princípio ativo, a redução na toxicidade em mamíferos e proteção ao homem e ao meio ambiente, mostrou-se muito promissora, necessitando-se ainda um estudo mais aprofundado para redução no tamanho das cápsulas para futuramente vir a ser utilizada para microencapsulamento de substâncias ativas.
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Microdiluição em caldo para teste de susceptibilidade de Malassezia furfur, Malassezia obtusa e Malassezia sympodialis

Souza, Victor Costa de 21 May 2010 (has links)
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Souza.pdf: 8939456 bytes, checksum: 0daae471197aedca86b8d195ca72ad7e (MD5) Previous issue date: 2010-05-21 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / In the Amazon, the tropical climate is the main factor that favors the development of superficial fungal infections and opportunistic, especially the high temperature and relative humidity, providing ideal conditions for continuity in the life cycle of pathogenic and opportunistic fungi. Among the most prevalent mycosis in this region, is pityriasis versicolor (PV), a major skin diseases treated at health care in dermatology, can affect people of both genders, age, race and social class. Different species of Malassezia spp., Some of which recently described by means of genetic studies, are responsible for PV and, despite its high prevalence in several regions of the world and in Brazil, there are few studies with more detailed approach on epidemiological, clinical and laboratory features of this mycosis in our region. Research on the susceptibility of these species to antifungal drugs is fundamental to the advancement of scientific knowledge in order to better clinical management and treatment of PV. The testing for evaluation of in vitro susceptibility to antifungal agents for yeasts and molds (vitro antifungal susceptibility), constitutes an important tool for monitoring the resistance of fungal strains and also to assist in choosing the best therapeutic regimen. Given this, the Clinical and Laboratory Standards Institute (CLSI), formerly National Committee for Clinical Laboratory Standards (NCCLS) have developed methods for the assessment of fungal susceptibility, however, due to different nutritional requirements of these species, there is still no specific protocol for testing with Malassezia spp. that has been recommended by this or any other body accredited for the regulation of clinical and laboratory procedures. The present study with the main objective to contribute to the development of a simplified protocol for assessing the susceptibility of three species of Malassezia, being isolated from 01 M. furfur, 01 and 01 M.obtusa M. sympodialis front to drugs ketoconazole, itraconazole and fluconazole. For this, bioassay were performed using the method in broth at different experimental conditions, which were defined from some methodological variants found in publications in the last 10 years, for the optimum conditions for growth, which were tested three different concentrations of inoculum, four types of culture media, incubation temperatures and two different criteria for interpretation of results. According to the results, the conditions that led to better performance during the experiments and the growth curves in bioassays with the drugs were: inoculum concentration of 0.5 to 2.5 x104 cells / mL and incubation temperature of 32 ° C; medium modified Leeming-Notman with some changes in its composition, and spectrophotometric reading at 620 nm after 3 days of incubation. Accordingly, the MIC values obtained were: MIC ≤ 0.03 mg / mL for ketoconazole and itraconazole to inhibit 50% and 80% of the growth of M. obtusa and M. furfur. For the fluconazole MICs were found for 2 and 4 mg / mL to inhibit 50% of the growth of M. sympodialis and M. obtusa respectively, and MIC of 4:08 g / mL for inhibition of 80%, while for M. furfur found an MIC ≤ 0.03 mg / mL of this drug to inhibit 50% and 80% of fungal growth. Therefore, although preliminary, considering the small number of samples analyzed, the results of this study provided important information in view of developing a protocol for susceptibility testing of Malassezia species. / Na região Amazônica, o clima tropical é o principal fator que favorece o desenvolvimento de infecções fúngicas superficiais e oportunistas, especialmente pela elevada temperatura e umidade relativa do ar, oferecendo condições ideais à continuidade no ciclo de vida dos fungos oportunistas e patogênicos. Dentre as micoses mais prevalentes nesta região, encontra-se a pitiríase versicolor (PV), uma das principais dermatoses atendidas nos serviços de saúde em dermatologia, podendo acometer pessoas de ambos os gêneros, idade, raça e classe social. Diferentes espécies do gênero Malassezia spp., algumas das quais recentemente descritas por meio de estudos genéticos, são responsáveis pela PV e, a despeito de sua alta prevalência em diversas regiões do mundo e no Brasil, ainda são poucos os estudos com abordagem mais aprofundada acerca dos aspectos epidemiológicos, clínicos e laboratoriais desta micose em nossa região. A investigação sobre a susceptibilidade destas espécies às drogas antifúngicas é de fundamental importância para o avanço do conhecimento científico na perspectiva de uma melhor abordagem clínica e terapêutica da PV. A realização de testes para avaliação da suscetibilidade in vitro aos agentes antifúngicos para leveduras e fungos filamentosos (antifungigrama), se constitui em uma importante ferramenta para o monitoramento da resistência de cepas fúngicas e também para auxiliar na escolha do melhor esquema terapêutico. Diante disto, o Clinical and Laboratorial Standards Institute (CLSI), antigo National Committee for Clinical Laboratory Standards (NCCLS), têm desenvolvido métodos de referência para a avaliação da susceptibilidade fúngica, entretanto, devido às exigências nutricionais diferenciadas dessas espécies, ainda não existe um protocolo específico para testes com Malassezia spp. que tenha sido recomendado por este ou por algum outro órgão credenciado para a regulamentação de procedimentos clínicos e laboratoriais. O presente estudo teve como objetivo principal contribuir para a elaboração de um protocolo simplificado para avaliação da susceptibilidade de três espécies de Malassezia, sendo, 01 isolado de M. furfur, 01 de M.obtusa e 01 de M. sympodialis frente às drogas cetoconazol, itraconazol e fluconazol. Para isto, foram realizados bioensaios com base no método de microdiluição em caldo, em diferentes condições experimentais, as quais foram definidas a partir de algumas variantes metodológicas encontradas em publicações nos últimos 10 anos, quanto às condições ótimas de crescimento, no qual foram testadas três diferentes concentrações de inoculo, quatro tipos de meios de cultura, duas temperaturas de incubação e diferentes critérios de leitura dos resultados. De acordo com os resultados obtidos, as condições que permitiram melhor desempenho durante os experimentos nas curvas de crescimento e nos bioensaios com a drogas foram: concentração do inoculo de 0,5 a 2,5x104 céls/mL; temperatura de incubação de 32 ºC; meio de cultura Leeming-Notman modificado com algumas alterações em sua composição, e leitura espectrofotométrica em 620nm após 3 dias de incubação. Nestas condições, os valores de CIMs obtidos foram: CIM ≤0,03 μg/mL, para o cetoconazol e itraconazol para inibir 50% e 80% do crescimento de M. obtusa e M. furfur. Para o fluconazol foram encontradas CIMs de 2 e de 4 μg/mL para inibir 50% do crescimento de M. sympodialis e M. obtusa respectivamente, e CIM de 4 e 8 μg/mL para inibição de 80%; enquanto que para M. furfur foi encontrada uma CIM ≤0,03 μg/mL desta droga para inibir 50% e 80% do crescimento fúngico. Portanto, apesar de preliminares, considerando o número reduzido de amostras analisadas, os resultados obtidos neste estudo forneceram informações importantes na perspectiva da elaboração de um protocolo para testes de susceptibilidade às espécies de Malassezia.
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Dynamique du phytoplancton et caractérisation physiologique et moléculaire de trois espèces autotrophes de la saline de Sfax(Tunisie), un milieu extrémophile. / Phytoplankton dynamics, physiological and molecularcharacterization of three autotrophic species from the solar saltern of Sfax (Tunisia), an extremophile environment

Masmoudi, Salma 16 June 2014 (has links)
La saline de Sfax est un environnement thalasso halin (milieu salé alimenté par de l’eau de mer) riche en plancton malgré la contrainte du sel et l’intensité lumineuse élevée. Cette richesse est due à ses facteurs physico-chimiques particuliers. L’analyse STATICO a mis en évidence que l’azote et le phosphore peuvent influencer la distribution du phytoplancton en plus de la salinité qui domine dans ce milieu particulier. En se basant sur ce dernier paramètre, nous avons pu regrouper les espèces selon leur tolérance au sel. Afin de mieux comprendre le comportement du phytoplancton, trois espèces autotrophes Dunaliella salina (Chlorophycée), Cylindrotheca closterium (diatomée) et Phormidium versicolor Cyanophycée) ont été isolées, identifiées puis cultivées en batch dans de l’eau de mer artificielle sous trois niveaux d’éclairement et en présence de trois concentrations en NaCl. La croissance, l’activité photosynthétique ainsi que l’activité enzymatique anti-oxydante ont été mesurées. L’appareil photosynthétique de la Chlorophycée et de la cyanobactérie est moins affecté que celui de la diatomée qui est irréversiblement altéré aux forts éclairements et à la plus forte salinité; l’activité antioxydante n’a été détectée que sous l’éclairement le plus élevé et la synthèse des pigments caroténoïdes, qui sont des anti-oxydants non enzymatiques, est fortement activée surtout chez D.salina. La salinité et le niveau d’éclairement inter-réagissent sur la physiologie des trois espèces qui possèdent des mécanismes de résistance aux stress plus ou moins efficaces, d’où des résistances différentes aux contraintes du milieu selon les espèces. / The saltern of Sfax is a thalasso haline environment (salt medium supplied with sea water) plankton-rich despite the high salinity and the high light intensity. This richness is due to its physico-chemical characteristics. The STATICO analysis shows that nitrogen and phosphorus can influence the distribution of the phytoplankton in addition to salinity that dominates in this peculiar medium. Basing on this parameter, we could group the species according to their salt tolerance. To better understand the behavior of the phytoplankton, three autotrophic species Dunaliella salina (Chlorophyceae) Cylindrotheca closterium (diatom) and Phormidiumversicolor (Cyanophycea) were isolated, identified and grown in batch in artificialseawater in the presence of three NaCI concentrations and under three irradiations. Growth, photosynthesis and antioxidant enzyme activity were measured. The photosynthetic apparatus of the Chlorophyceae and the cyanobacteriumwas less affected than the diatom’s one that was irreversibly altered under high illumination and the highest salinity ; the antioxidant activity was only detected in cells grown under the highest irradiance and the synthesis of carotenoid pigments, that are non-enzymatic antioxidants,was strongly activated especially in D.salina. Salinity and light inter-reacted on the physiology of the three species that possess resistance mechanisms to stresses more or less effective, resulting in different resistance to environmental stresses depending on species.
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Comportamiento al biodeterioro de madera de pino radiata (Pinus radiata D.Don) tratado con cobre-azol (CA-B), contra hongos de pudrición y termita subterránea

Ramírez Farfán, Álvaro Felipe January 2017 (has links)
Memoria para optar al Título Profesional de Ingeniero Forestal / La madera de pino radiata, principal recurso maderero del país, es de baja durabilidad. Hongos e insectos, entre otros factores de su deterioro, son usualmente los más relevantes. Del grupo de los insectos, en particular la termita subterránea “Reticulitermes flavipes”, representa hoy la mayor preocupación, por su agresividad y avance permanente en áreas pobladas del país. El arseniato de cobre cromado (CCA) fue, por décadas, el preservante más utilizado en todo el mundo para proteger la madera, sin embargo, preocupaciones medioambientales, hace más de diez años, dieron paso a un cambio hacia otros productos. El uso de cobreazoles (CA) y en particular el de tipo B, junto con cobreazol micronizado, han sido los cambios más importantes desde entonces a nivel mundial. Su incorporación al mercado local, sin embargo, ha sido muy lenta, básicamente por costo y por no existir un marco legal que regule el uso de madera tratada con CCA. Sobre la base de los requisitos exigidos por la Australian Standard®, AS 1604.1-2012, para madera tratada con CA-B, el objetivo del estudio fue evaluar el comportamiento de madera de Pino radiata tratada con CA-B, a retenciones menores a las exigidas por la Norma Chilena, frente al ataque de hongos de pudrición y termita subterránea. Los métodos empleados fueron; “Standard Test Method for Wood Preservatives by Laboratory Soil-Block Cultures”, descrito en la ASTM Designation: D1413 − 07ɛ1 y la Norma Chilena NCh 3060.Of 2007, para el estudio con hongos y termita subterránea respectivamente. En el estudio con Lentinus lipideus, todos los grupos de retención presentaron efecto positivo en el control del hongo y diferencias estadísticamente significativas respecto a las probetas testigo. En el caso de Coriolus versicolor, solo los grupos de retención 1,4 y 1,8 kg/m3 se diferenciaron estadísticamente del testigo en el control del hongo. En el estudio contra termita subterránea, la retención necesaria de CA-B para el control de Reticulermes flavipes se ubicó entre las retenciones 1,4 y 1,8 kg/m3 (concordante con la Norma NCh 819:2012). Una retención menor en pino radiata tratado con CA-B, no pudo ser validada para el control de termita subterránea, Reticulermes flavipes.

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