Made available in DSpace on 2016-06-02T19:26:20Z (GMT). No. of bitstreams: 1 OLIVEIRA_JUNIOR_Paulo_2012.pdf: 2558678 bytes, checksum: a031764ca6a58411f3a5fd0752aac91f (MD5) Previous issue date: 2012-06-28 / Financiadora de Estudos e Projetos / Several critically endangered species and subspecies have been saved from extinction in recent years by Ex Situ conservation strategies. However, captive populations are generally small and exposed to the effects of genetic drift, inbreeding and founder effects. Thus, a major challenge for long-term reproduction of these animals is to reduce the loss of heterozygosity and of allelic diversity. The genetic management can guide the matings to maintain the genetic variation as high as possible in the population. It can be achieved by calculating the genetic distance between the specimens, which is performed using molecular biology techniques. The Black-fronted Piping-Guan, Aburria jacutinga (Aves, Cracidae), is an endemic bird of the Atlantic Forest that is threatened of extinction due to the drastic destruction of this biome and the heavy hunting pressure. Among the suggested conservation actions for this species are the development of an Ex Situ conservation program with the goal of making reintroductions in areas where it has become extinct, as well as the maintenance of these captivity stocks controlled by a studbook. Here we have genotyped and analyzed 146 individuals from the five main breeding facilities. The results demonstrated five genetically differentiated populations of Black-fronted Piping-Guan, but their levels of genetic variability were very similar. However when these levels are compared with other species, the data suggest that the genetic variation is lower than desirable to reach the objectives proposed by the Ex Situ conservation programs. Pairing tables and genetic rankings were constructed and indicated kinship and levels of genetic variability of each bird. It was possible to identify the best pairs to be mated and individuals that were adequate for reintroductions. / Diversas espécies e subespécies criticamente ameaçadas foram salvas da extinção nos últimos anos por meio de estratégias de conservação Ex Situ. Porém, as populações de cativeiro são geralmente pequenas, e quanto menor uma população, mais exposta ela se torna aos efeitos da deriva genética, endocruzamento e efeitos fundadores. Assim, um dos grandes desafios para a reprodução em longo prazo desses animais é amenizar a perda de diversidade alélica e heterozigose. O manejo genético pode orientar os acasalamentos de maneira a manter na população a maior variação genética possível através do cálculo da distância genética entre os espécimes, que é realizado por técnicas de biologia molecular. A jacutinga, Aburria jacutinga (Aves, Cracidae), é uma ave endêmica da Mata Atlântica que está ameaçada de extinção devido à drástica destruição deste bioma e à forte pressão de caça. Dentre as ações de conservação sugeridas para esta espécie estão o desenvolvimento de um programa de conservação Ex Situ visando a reintrodução em áreas nas quais ela se tornou extinta e a manutenção desses estoques em cativeiro controlados por um studbook. Foram genotipados e analisados 146 indivíduos oriundos de cativeiro. Os resultados demonstram 5 populações diferenciadas geneticamente de jacutinga, mas seus níveis de variabilidade genética são bastante semelhantes. Entretanto quando esses níveis são comparados com outras espécies, os dados sugerem que a variação genética está abaixo do desejável para se alcançar os objetivos propostos pelos programas de conservação Ex Situ. Tabelas de pareamento e rankings genéticos foram construídos e indicam as relações de parentesco e níveis de variabilidade genética de cada ave. Com eles foi possível apontar os melhores pares a serem acasalados e os indivíduos que estão aptos a serem reintroduzidos.

Em razão da intensa atividade industrial e da ampla utilização de compostos derivados do petróleo pela indústria, compostos aromáticos, principalmente os BTEX (benzeno, tolueno, etilbenzeno e xilenos) são freqüentemente encontrados em aqüíferos contaminados, em especial em casos de contaminação por vazamento de tanques de armazenagem subterrânea de combustíveis. Nesse sentido, o presente trabalho foi proposto com o intuito de desenvolver um sistema capaz de remover tanto os BTEX quanto à matéria orgânica presente e efluentes e aqüíferos contaminados com gasolina. Foi constatada a viabilidade técnica da aplicação do RAHLF sob condições metanogênicas operando com TDH de 16 horas em que foi verificada a remoção de 99% da matéria orgânica e em torno de 95% dos BTX, apresentando as seguintes concentrações no efluente (benzeno - 0,62 +/- 0,41 mg/L; tolueno - 0,71 +/- 0,46 mg/L; meta-xileno - 0,28 +/- 0,19 mg/L). Os valores estimados para as constantes cinéticas pelo modelo cinético de primeira ordem com residual para a remoção dos BTX foram muito superiores, cerca de cem vezes maiores do que os encontrados na literatura. A caracterização microbiana do RAHLF metanogênico mostrou a estratificação ao longo do leito. Segundo as análises empregando a técnica de FISH, verificou-se o predomínio dos domínios Archaea no primeiro trecho do reator o que ocorreu, provavelmente, devido a presença de ácido acético proveniente da degradação do etanol, constituinte principal da gasolina vendida no Brasil. Já de acordo com os padrões de bandas de DGGE obtidos a partir dos primers universais para o domínio Bacteria e para o domínio Archaea, estes permitiram constatar certa diferença na diversidade genética entre o ponto zero e o resto do reator. Em relação ao RAHLF sob condições desnitrificantes a remoção quase total de nitrato e BTX ocorreu praticamente no primeiro trecho do reator levando a uma operação em um regime de metabolismo misto (metanogênico e desnitrificante). Em virtude do esgotamento do íon nitrato no primeiro trecho do reator e da ausência de biomassa adaptada ao processo de metanogênese acetoclástica, o RAHLF apresentou desbalanceamento do metabolismo anaeróbio levando ao acúmulo de ácido acético nos primeiros 140 dias de operação. O estudo cinético da degradação dos BTX em solução etanólica realizado no reator anaeróbio com biomassa imobilizada operado em bateladas seqüenciais levou a construção de modelo que descreveu com grande precisão os processos físicos e metabólicos principais envolvidos na degradação do etanol e remoção dos BTX. Tal modelo proporciona uma ferramenta adequada para o dimensionamento de reatores em escala piloto. / Due to the intense industrial activity and the wide range of applications for the petroleum-derived substances by the industry, several aromatic compounds, mainly the BTEX (benzene, toluene, ethylbenzene and xylenes), are often found in contaminated aquifers, specially in the cases of spilling of oil storage tanks. In this sense, the present work intended to develop a system useful for simultaneous BTEX and organic matter removal present in wastewaters and aquifers contaminated with gasoline. The technical viability of the HAIB (horizontal anaerobic immobilized biomass) reactor was evidenced when it was operated with a HDT of 16 hours, condition where removal percentages of about 99% of organic matter and 95% of BTX were reached. The kinetic constants were calculated employing the apparent first-order model with residual concentration, and the results showed that the constants estimated for the BTX were approximately 100 times higher than the ones found in the literature. According to the analysis employing the FISH technique, it was verified a predominance of Archaea in the first part of the reactor, probably due to the high concentrations of acetic acid produced by the degradation of ethanol. As for the DGGE-profile obtained from the universal primers for the Bacteria and Archaea, they showed some differences among the different sample points of the reactor. As for the denitrifying HAIB, there was almost total removal of nitrate and BTX in the first section of the reactor, fact that probably led it to operate in a mixed metabolism (methanogenic and denitrifying). Due to this depletion and to the absence of biomass adapted to the acetoclastic methanogenesis, the HAIB presented disequilibria in the anaerobic metabolism, fact that caused an accumulation of acetic acid in the first 140 days of operation. The kinetic study of BTX degradation in the ethanolic solution carried out in the anaerobic reactor with immobilized biomass operated in batch mode led to a mathematical model that described with great accuracy the main physical and metabolic processes involved in the ethanol degradation and removal of BTX. This model probably provides a suitable tool for the design of pilot scale reactors.

The rivers, lakes and seas are the major water sources for the animal and plant kingdom in this earth. In recent times, the usage and wastage of water have been increasing due to the uncontrolled population growth. In addition to that, the rapid industrialization over the years has led to the gradual depletion of the natural resources like water, soil and air. Some of these industries discharge contaminants like organic products and inorganic (or) toxic heavy metals without treatment into the environment, leading to its degradation. Zinc is the 24th most abundant element present in the earth crust, amounting 75 ppm (0.0075%). The concentration of zinc present in the soil and seawater is about 64 ppm and 30 ppb respectively (Emsley, 2001). Generally, the zinc is found with the base metals such as copper and lead and it has less affinity with oxides and strong affinity with sulphides. Sphalerite, a zinc sulphide ore, is majorly containing 60-62% of zinc. The other sources of zinc from the minerals are smithsonite, hemimorphite, quartzite, and hydro zincate. The major sources of zinc contamination arise from several industrial activities such as mining, coal, waste combustion and steel and iron processing. Drinking water also contains certain amounts of Zn, which may be higher when it is stored in metal tanks. The acute toxicity arises from the ingestion of excessive amounts of zinc salts, either accidentally or as dietary supplement. Vomiting, nausea and stomach cramps usually occur after the consumption of more than 500 mg of zinc sulfate. In addition to that, the higher amounts of zinc affect gastrointestinal tract, liver, bone and prostate glands. Finally, Zn can interrupt the activity in soils, as it negatively influences the activity of microorganisms and earthworms, thus retarding the breakdown of organic matter. To combat this problem, techniques such as chemical precipitation, ion exchange, reverse osmosis, etc. are adopted, but these processes result in a huge amount of secondary sludge formation, inefficient removal of metals and are not cost effective. In recent times, an innovative, eco-friendly, cost-effective method has been introduced to treat the toxic heavy metals namely bioremediation. ―Bioremediation‖ is a process of removal of organic or inorganic contaminants by using bacteria, fungi, algae and its metabolites In this research work, the potential of four bacterial strains of the Pseudomonas sp. such as P.putida, P.alcaligenes, P.aeruginosa and P.fluorescens and the extracellular proteins secreted by these four species for the bio-sorption of zinc has been investigated through batch experiments. The mechanisms of interaction between the zinc ion and the bacterial biomass as well as with the extracellular proteins have been elucidated. Additionally, a carbon paste electrode has been modified by using Pseudomonas sp. and its metabolites to develop biosensors for zinc and the lower limit of detection of zinc in aqueous solution has been determined. The major objectives of this research work are specified below: • To study the potential of Pseudomonas sp. such as P.putida, P.alcaligenes, P.aeruginosa and P.fluorescens for the bio sorption of zinc, in batch systems. • To determine the speciation of zinc with respect to pH in the growth medium and the maximum inhibitory effect of zinc on the growth of the four chosen Pseudomonas sp. • To isolate and characterize the extracellular proteins from the four Pseudomonas sp. such as P.putida, P.alcaligenes, P.aeruginosa and P.fluorescens. • To study the biosorption of zinc by extracellular proteins secreted by the Pseudomonas sp. • To elucidate the mechanisms involved in the biosorption of zinc at the microbe- metal interface and protein-metal ion interface for all the four systems by different characterization studies such as zeta potential, FTIR analysis and EDAX analysis. • To develop a biomass modified CPE using bacterial cells and extracellular protein to detect the concentration of zinc in aqueous solutions adopting voltammetric techniques. The significant results obtained from this research work are summarized as follows: The initial studies were concentrated on the bio sorption of zinc by using four Pseudomonas species such as P.putida, P.alcaligenes, P.aeruginosa and P.fluorescens. The various factors affecting the bio sorption of zinc by these species were investigated by varying the contact time (10-80 min), pH (2-5±0.2), biomass concentration of the four species in the range of 108- 1011 cells / mL, and the initial zinc concentration from 5 mg/L to 80 mg/L respectively, keeping other parameters such as temperature and agitation speed constant in all the experiments. From the results obtained, the maximum percentage of biosorption achieved by the P.putida, P.alcaligenes, P.aeruginosa and P.fluorescens was found to be 60%, 93%, 70% and 65% respectively for 25 mg/L at pH 5±0.2. The equilibrium time taken by the four species to achieve maximum biosorption was about 10 min and the biosorption kinetics adhered to pseudo-second order reaction and the rate constants were determined for different concentrations of zinc. The biosorption isotherm followed both the Langmuir and Freundlich isotherm models. The Gibbs free energy (ΔG) values determined from the Langmuir isotherm model for all the four systems were found to be -26, -32, -30 and -28 kJ /mole respectively. The Gibbs free energy values indicate that the biosorption of zinc ions onto the bacterial surface is a chemi-sorption process involving co-ordination, complexation or chelation. The characterization studies, namely zeta potential, FTIR analysis and SEM-EDX were also carried out on the bacterial cells before and after interaction with zinc. These studies also provide evidence in support of the complexation of zinc with the functional groups on the bacterial cell surface apart from electrostatic interaction. In the second part of the investigation, the inhibitory effect of zinc on the growth of four Pseudomonas sp. was investigated by varying the concentration of zinc from 50 mg/L to 1000 mg/L and the stability of zinc was analysed with respect to pH (2-12) with different concentrations from 50 - 1700 mg/L. It was found that in the absence of zinc the time taken to reach the exponential phase and the specific growth were almost the same for all the four systems. However, in the presence of zinc ions, the growth of the four Pseudomonas sp. was suppressed beyond 50mg/L of zinc. A control study on the stability of zinc in Luria broth medium showed that zinc was highly stable up to 200 mg/L from pH 2-8. However, the stability of zinc in the growth medium decreased beyond that concentration Additionally, studies on the biosorption of zinc were performed using extracellular proteins isolated from the four Pseudomonas sp. The amount of protein was estimated by the Bradford protein assay method at 594 nm. The biosorption experiments were carried out by varying the protein concentration from 50 to 1000µg/mL and the zinc concentration from 50-1000 mg/L and keeping other parameters fixed, namely such as pH at 5±0.2, reaction time of 20 min, temperature at 30±0.2 and the speed of rotation of 200 rpm. It was found that the maximum percentage of zinc biosorbed by the proteins isolated from P.putida was found to be 91% at 500µg/mL of protein concentration and from the other three species, it was found to be about 60% of biosorption at the same protein concentration. The biosorption isotherms of zinc for extracellular protein adhered to the Giles H1 type for all the four systems. The maximum amount of zinc biosorbed by the protein isolated from P.putida, P.alcaligenes, P.aeruginosa and P.fluorescens was found to be 35.6, 19,18.3 and 10 mg/µg respectively and the Gibbs free energy values were found to be -32, -22,-22 and -23 kJ/mole. The mechanisms involved in protein-zinc interaction were elucidated using FTIR analysis and EDX analysis. The FTIR analysis revealed, that the zinc ions were complexed with carboxylic and amine functional groups. Further, the potential of P.putida, P.alcaligenes, P.aeruginosa and P.fluorescens and their extracellular proteins of P.putida as biosensors for detecting zinc ions in aqueous solutions, using electrochemical methods such as, Cyclic Voltammetry and Differential pulse anodic stripping voltammetry, was assessed. The developed carbon paste electrode coated by the biomass showed an approximately 3-fold increase in the sensing of Zn2+ ion in comparison with the bare electrode. The lower limit of detection of the biosensor for zinc ions by Cyclic voltammetry was found to be 10-6 M, and in case of DPASV the lower limit of detection was about 10-7M. The lower limit of detection of the protein modified biosensor for zinc ions by cyclic voltammetry was found to be 10-7M and in the case of DPASV method the lower limit of detection was found to be 10-9 M.

Crambe crambe (Schmidt, 1862), espèce largement retrouvée en Méditerranée, est la source de nombreuxalcaloïdes guanidiniques (crambescines et crambescidines). Les voies de biosynthèse de ces métabolitessecondaires n’ont pas encore été démontrées. Il a cependant été proposé que les crambescidines seraientproduites à partir de polycétides, suggérant ainsi la possible implication de micro-organismes dans leurbiosynthèse. Cependant les quelques études portant sur la présence ou non de bactéries associées à cette épongesont contradictoires. Durant cette thèse, nous avons caractérisé la communauté bactérienne associée à C. crambepar l’utilisation de techniques à la fois moléculaires et microscopiques, mettant en évidence l’associationspécifique entre une bêtaprotéobactérie et cette éponge méditerranéenne. La présence d’un micro-organismespécifique au sein du mésohyle de l’éponge pose alors la question du rôle de ce dernier au sein de son hôte etplus particulièrement sa possible implication dans la synthèse des alcaloïdes guanidiniques. L’étude de ladiversité microbienne cultivable par la mise en place d’une procédure d’acclimatation et la conception de diversmilieux de cultures, a permis l’isolement de micro-organismes minoritairement associés à C. crambe, mais n’acependant pas conduit à l’isolement de la bêtaprotéobactérie spécifique. La comparaison des empreinteschimiques (CLHP/DAD/ELSD – CLHP/ESIMS) des extraits de l’éponge et des bactéries cultivées, a révélé queces micro-organismes minoritaires n’étaient pas à eux seuls producteurs de ces métabolites bioactifs. La bactériemajoritaire, principale candidate dans la synthèse des métabolites n’étant pas cultivable, nous avons développédeux études complémentaires afin d’apporter des éléments de réflexion quant à sa possible implication. Laculture ex situ de colonies C. crambe accompagnée d’un stress pH ainsi que l’étude de la distribution spatiale insitu des composés par imagerie par spectrométrie de masse se révèlent prometteuses bien qu’elles n’aient pas, àce jour permis d’identifier le possible rôle de la bêtaprotéobactérie dans la biosynthèse de ces métabolites. / Crambe crambe (Schmidt, 1862), is a marine sponge widely distributed in the Mediterranean Sea and known toproduce bioactive guanidine alkaloids (crambescins and crambescidins). While the biosynthetic pathways ofthese metabolites remains unknown, bio-mimetic chemical synthesis of crambescidins suggested a possiblecontribution of microorganisms in their biosynthesis. Contrastingly, it had been reported via electron microscopythat bacteria were absent in the tissues of this sponge. Thus to shed light onto these contrasting results I studiedthe microbial community associated with C. crambe using alternative approaches. Using molecular andmicroscopic techniques, we demonstrated that a single bacterial species affiliated to the Betaproteobacteria ispresent in abundances commonly found in low microbial abundance sponges, and dominates the bacterialcommunity associated with C. crambe. This finding suggests a possible implication of bacteria the biosynthesisof C. crambe’s guanidine alkaloids. The use of acclimatization procedure and diverse cultivation approachesallowed the isolation of associated microorganisms which were rare or absent among the community describedvia tag pyrosequencing but not isolation of the dominant betaproteobacterium. CLHP/DAD/ELSD andCLHP/ESIMS fingerprints of extracts from C. crambe and from the isolated bacteria showed no evidence of theimplication of these cultured micro-organismes in the synthesis of C. crambe’s metabolites. Finally in order toevaluate the potential role of the uncultivated betaproteobacterial symbiont in the biosynthesis of guanidiniumalkaloids, preliminary experiments using two alternative approaches were attempted. In the first I subjectedsponges to a pH stress and evaluated changes in secondary metabolite profiles, while collecting samples formicrobial community analysis. In the second I tried different mass spectrometry imaging techniques to localizeguanidinium alkaloids in C. crambe tissues. While these experiments did not allow to resolve the question of apossible implication of the dominant betaproteobacterium in the biosynthesis of the pentacyclic guanidinealkaloids, I was able to gather interesting results that will guide future studies towards resolving this question.

The work describes the design and manufacturing of a test device for post-mortem measurements of electrodes of electrochemical cells using X-ray diffraction spectroscopy. The theoretical part describes the diffractometer Rigaku Miniflex 600, for which the product is intended. At the same time, an overview of solutions in various applications is processed here in the form of a recherche. The practical part documents the current development of a new cell, on which tests were performed. Here is an overview of the influence of gases and insulating materials on the resulting data, especially distortion and attenuation. Subsequently, a new design with improved hermetic insulation and sample displacement error correction is described. The principle of operation of the manufactured cell, including the control unit and software, is elaborated in the form of technical documentation. Finally, the functionality is verified by comparing the diffractograms of the powder standards and the graphite electrodes.

<p>Meteorites fallen from the sky and surface particles of the moon gathered by lunar space missions, have distinct microstructure and properties that can provide unique insights on the origins and processes for the evolution of our solar system. These extraterrestrial materials contain highly complex microstructures due to the formation and structure evolution events spanning long periods of time. The comprehensive characterization on these samples, to extract multi-scale structural information, is especially crucial to support formation theories, understand material utilization possibility, and preparation for potential hazard mitigation. In addition to the microstructure, an understanding of the mechanical properties of these materials is also vital. Hence, an in-depth investigation on how microstructural phase distribution and their respective mechanical properties connect to macroscopic deformation behavior is required.</p> <p>In this study, a correlative microscopy-based methodology was used to study several celestial samples; meteorite Aba Panu (L3), meteorite Tamdakht (H5), and a lunar dust grain from mature sample 10084 returned by the Apollo 11 mission. X-ray microcomputed tomography (XCT) was utilized to acquire inherent 3D structural details from samples non-destructively. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) was used to further resolve finer structural features and compositional information to complete the correlative described above.</p> <p>Both ex situ and in situ compression experiments, in the XCT, were performed on machined cylindrical samples of Aba Panu meteorite. Structure development including crack initiation, propagation, and failure states were analyzed and correlated to the macroscopic stress-strain behavior. Direct 3D correlation on ex situ and in situ images of crack growth were used to obtain a comprehensive mechanistic understanding of crack development and deformation. Finally, nanoindentation was used to complement the 3D microstructural study, by acquiring mechanical properties of individual constituent phases.</p> <p><br></p>

Additive friction stir deposition (AFSD) is an innovative solid-state manufacturing process capable of producing parts with fine, equiaxed grains. However, due to the complexity of extensive plastic deformation and the viscoplastic behavior of metallic materials at elevated temperatures, the analysis of material flow and stress evolution during AFSD remains at a rudimentary stage. As a developing technology, gaining a deeper understanding of the underlying physical behaviors behind the processing is appreciable. This study comprises three objectives: investigating microstructure and stress-induced acoustic wave propagation behaviors, implementing non-contact in-situ monitoring in AFSD of aluminum alloy 6061 using a far-collimation acoustic metamaterial lens, and ex-situ analysis of parameter-dependent mechanics influences in AFSD of aluminum alloys 6061. To achieve this, a novel ultrasound in-situ monitoring method, along with ex-situ residual stress measurements, is facilitated by MD and FEA simulations and been experimentally verified. Real-time asymmetric property distribution and abnormal parameter-dependence acoustic wave phase change during the AFSD of aluminum alloy 6061 were identified through the in-situ monitoring and further investigated in detail through ex-situ inspection. A key parameter, effective viscosity, was introduced to the parameter windows selections, which can affect the thermo-fluidic mechanics during the process, thereby altering the physical aspects, mechanical properties, and microstructures.

Made available in DSpace on 2014-07-29T14:52:10Z (GMT). No. of bitstreams: 1 Tese_Rita_Maria_Devos_Ganga.pdf: 530368 bytes, checksum: 313a466ca42e845ba20f6b19bca53337 (MD5) Previous issue date: 2008-07-30 / The mangaba tree (Hancornia speciosa Gomes) is a fruit tree native from Brazil with potential for domestication, due to its excellent smell, flavor and texture. However, genetic conservation and breeding programs of these species are in an initial developmental phase. This way, this research aimed to characterize trees and fruits of natural populations of H. speciosa, as well as evaluate the distribution of phenotypic variability among them; evaluate progenies of mangaba trees that compose the Escola de Agronomia e Engenharia de Alimentos of Universidade Federal de Goiás (EA/UFG) germplasm collection and estimate genetic parameters for the initial development of plants in the field. Mangaba trees populations have been sampled in different locations of the Brazilian Cerrado, including the states of Goiás, Tocantins, Mato Grosso, Mato Grosso do Sul, and Bahia, totaling 109 mother plants of 35 populations of the botanic varieties pubescens, gardneri, speciosa and cuyabensis. In relation to the trees, plant height, stem perimeter, and number of fruits per plant were taken. From a sample of five fruits per plant, individual measures have been taken, such as: length, diameter, weight, total weight of seeds, average seed weight, pulp plus peel weight, seed number per fruit, pulp plus peel yield, fruit shape and color and estimated production. Seeds from these mother plants were used to install the EA/UFG mangaba germplasm collection in December 2005, in a randomized complete block design with 57 treatments, four replications and one plant per plot in a 5 m x 6 m spacing. The treatments were open pollination progenies, originated from 28 natural populations. The characteristics plant height and stem basal diameter were evaluated in all plants from January 2006 to August 2007, which resulted in 20 data readings. Data from each plant has been transformed into growth rate. The analyses of variance and the genetic parameter estimates were obtained to the growth rate and to the data of latest reading of stem diameter and plant height. The progress was estimated by simulating genetic selection in both sexes and maternal selection. In Cerrado conditions, the results showed that H. speciosa mother plants show high levels of phenotypic variation in fruit characters and most of this variation is among populations. There is a large phenotypic variability in the varieties too. H. speciosa var. gardneri and H. speciosa var. pubescens fruits are larger and heavier. The botanic variety gardneri shows gait more high than the others varieties. In the varieties gardneri and pubescens predominate round shape and light green color, while in speciosa and cuyabensis predominate oblong shape and dark yellow and dark green colors, respectively. The varieties gardneri and pubescens stand out as the most promising for selection based on fruit size and fruit weight. The mangaba tree progenies of the germplasm collection of EA/UFG present high levels of genetic variation in stem diameter and plant height and to their growth rates. Most of the genetic variation in stem diameter is within populations and to plant height is among populations. H. speciosa var. cuyabensis and H. speciosa var. gardneri show greater growth in stem diameter and plant height. On account of the expected progress of selection, the collection can be used as seed orchard or clonal garden, without plant thinning, collecting seeds or buds of superior plants. The maternal selection is recommended to maintain greater variability in future breeding cycles, permitting progress from selection and maintaining the germoplasm collection intact. / A mangabeira (Hancornia speciosa Gomes) é uma espécie frutífera nativa do Brasil com potencial para domesticação, devido as suas excelentes qualidades de aroma, sabor e textura. Entretanto, programas de conservação genética e melhoramento desta espécie estão em fase inicial de desenvolvimento. Nesse sentido, este trabalho objetivou caracterizar árvores e frutos de populações naturais de H. speciosa e avaliar a magnitude e distribuição da variabilidade fenotípica existente entre elas; avaliar progênies de mangabeira que compõem a coleção de germoplasma da Escola de Agronomia e Engenharia de Alimentos da Universidade Federal de Goiás (EA/UFG) e estimar parâmetros genéticos relativos ao desenvolvimento inicial de plantas no campo. Populações de mangabeiras foram amostradas em diferentes locais do Cerrado brasileiro, incluindo os estados de Goiás, Tocantins, Mato Grosso, Mato Grosso do Sul e Bahia, abrangendo 109 matrizes de 35 populações das variedades botânicas pubescens, gardneri, speciosa e cuyabensis. Nas árvores foram obtidos dados relativos à altura da planta, perímetro do caule a 10 cm do solo e contagem do número de frutos por planta. Tomandose uma amostra de cinco frutos por planta, realizaram-se as análises físicas individualizadas por fruto: comprimento, diâmetro, peso, peso total de sementes, peso médio de uma semente, peso da polpa mais casca, número de sementes por fruto, rendimento de polpa mais casca, formato e cor do fruto e produção estimada. Sementes provenientes dessas matrizes foram utilizadas na implantação da coleção de germoplasma da espécie na EA/UFG em dezembro de 2005, em delineamento experimental de blocos completos casualizados com 57 tratamentos, quatro repetições e uma planta por parcela no espaçamento de 5 m x 6 m. Os tratamentos foram constituídos por progênies de polinização livre, abrangendo 28 populações das quatro variedades citadas. Foram avaliados os caracteres altura das plantas e diâmetro basal do caule em todas as plantas, durante o período de janeiro de 2006 a agosto de 2007, totalizando 20 leituras que foram transformadas em taxas de crescimento mensais. A altura e o diâmetro das leituras finais também foram analisados. Ganhos de seleção foram estimados entre progênies, simulando seleção em dois sexos e seleção materna. Nas condições do Cerrado, as matrizes de H. speciosa apresentam elevados níveis de variação fenotípica quanto a caracteres de frutos, sendo que a maioria dessa variação está entre populações. Há, também, uma grande variação fenotípica dentro das variedades botânicas. H. speciosa var. gardneri e H. speciosa var. pubescens têm frutos maiores e mais pesados. A variedade botânica gardneri apresenta porte mais alto que as demais. Nas variedades gardneri e pubescens predominam frutos redondos e verde-claros, enquanto que em speciosa e cuyabensis predominam frutos de formato oblongo e coloração amarelo-escura e verde-escura, respectivamente. As variedades gardneri e pubescens destacam-se como de maior potencial para a seleção baseada em caracteres de tamanho e peso dos frutos. As progênies de mangabeira representadas na coleção de germoplasma da Escola de Agronomia e Engenharia de Alimentos apresentam altos níveis de variação genética para os caracteres de diâmetro do caule e altura de plantas e taxas de crescimento. Para o diâmetro do caule, a maior parte da variação genética está dentro de populações e para a altura está entre populações. H. speciosa var. cuyabensis e H. speciosa var. gardneri apresentam maior desenvolvimento em campo em relação ao diâmetro do caule e à altura das plantas. Em razão dos progressos esperados, a coleção pode ser usada como campo de sementes ou jardim clonal, sem desbaste de plantas, coletando sementes ou gemas nas plantas superiores. A seleção materna é recomendada por manter maior variabilidade nos ciclos seguintes, além de possibilitar progresso por seleção e manter intacta a coleção de germoplasma.

The genus Restrepia is well known to orchid enthusiasts but its micromorphology has not been described, and its pollination and breeding systems have not been investigated. The aim of this investigation was, therefore, to add to existing knowledge so that the resultant data could be used to facilitate ex situ conservation initiatives. A detailed electron microscopy study (SEM) of the floral organs was performed. This confirmed the structure of the dorsal sepal and lateral petal osmophores, their secretory nature together with that of the synsepal and the labellum. It was postulated how, by manipulating different labellar surface textures, the flower might use these ‘tactile guides’ to steer the insect (fly) through the flower. The cirrhi were postulated to help by destabilising the pollinator in flight, trapping it and bringing about pollination. The papillate structure of the calli was established and their optical properties investigated. Media comparison investigations established that Western medium supported the highest germination rates and, with the addition of banana supplement, the highest rates for seedling growth and development. This represented the first protocol for axenic germination of Restrepia in the literature (Millner et al., 2008) and provided a tested methodology for investigating breeding systems and producing Restrepia plant material for both scientific and horticultural purposes. Self-pollinations were found to produce fewer embryos compared to cross-pollinations. The operation of self-incompatibility (SI) was confirmed by the study of pollen tube growth which further confirmed the time interval between pollination and fertilisation. A time line from pollination/fertilisation to flowering was established. The type of SI in operation was best explained by gametophytic incompatibility. This demonstrated that it was possible to raise Restrepia hybrids and species from seed, by performing intraspecific crosses so helping to preserve them for posterity and relieve pressure on wild populations. Narrow endemic Restrepia species face combined threats from habitat loss, habitat degradation and problems of viable seed production due to the effects of SI and inbreeding depression (ID). Recently developed online resources, such as GeoCAT, were used to perform a Red List assessment in order to identify the degree of threat individual species faced, both globally and nationally. All species were classified as facing substantial levels of threat; although this was lessened for populations in protected habitats. Conservation is needed for cultivated collections as well as these wild populations by keeping alive existing knowledge and expertise in growing these species.

Le devenir des hydrocarbures (HC) dans les environnements hypersalins constitue une problématique environnementale majeure. Ce travail pour objectifs (1) d’évaluer l’impact d’une pollution pétrolière sur les communautés microbiennes d’un milieu hypersalin, (2) de déterminer comment les archées hydrocarbonoclastes accèdent aux HC et, (3) de déterminer si la biodégradation est possible en conditions anaérobies dans ces environnements hypersalés. Nous avons démontré qu’une biodégradation modérée du pétrole est possible en milieu hypersalin environ 10 % de la fraction aliphatique du pétrole sont biodégradé. Une disparition progressive des composés aromatiques les plus légers est également observée, liée aux processus abiotiques. La dynamique des communautés procaryotiques montre un changement dans la structure de la communauté bactérienne autochtone des saumures. Une résistance à la contamination pétrolière a en revanche été observée pour les communautés archéennes des saumures. Dans une deuxième partie du travail, nous avons pu montrer, à l’aide d’une souche d’archée hyperhalophile modèle (Haloferax volcanii MSCN14), que les archées hydrocarbonoclastes de ces environnements mettent en oeuvre plusieurs mécanismes leur permettant d’augmenter la biodisponibilité des HC. Dans une dernière partie des travaux, nous avons testé les capacités d’une souche modèle (Hfx. volcanii MSNC 16) à dégrader les HC en anaérobiose. Si Hfx. volcanii MSNC16 est bien capable d’utiliser le fumarate comme accepteur terminal d’électrons, elle n’est en revanche pas capable de dégrader l’alcane testé (heptadécane) en absence d’oxygène. / The fate of hydrocarbons (HC) in hypersaline environments is an important environmental issue. This work aimed to (1) assess the impact of oil pollution on microbial communities of a hypersaline environment, (2) determine how hydrocarbonoclastic archaea can access to HC and (3) whether biodegradation is possible in these hypersaline environments in the absence of oxygen. We have shown that moderate oil biodegradation is possible under hypersaline conditions. In these conditions close to natural ones, about 10% of the aliphatic hydrocarbons were biodegrade. A gradual disappearance of the lighter aromatic compounds was also observed, but these losses were mainly due to abiotic processes. The monitoring of prokaryotic communities based on molecular fingerprints showed a change in the structure of the indigenous bacterial community. On the contrary, resistance to oil contamination was observed among the indigenous archaeal communities of brines. In the second part of this work, laboratory cultures of a hyperhalophilic archaeal strain (Haloferax volcanii MSCN14), allowed to demonstrate that, in hypersaline environments, hydrocarbonoclastic archaea use several strategies to increase the bioavailability of HC. Indeed, strain MSCN14 was capable of producing one or several biosurfactants during growth on different HC, and was adhering to the surface of the HC. In the last part of this work, we tested the capacities of a model archaeal strain (Hfx. volcanii MSNC 16) to degrade HC anaerobically. If Hfx. volcanii MSNC16 was able to use fumarate as a terminal electron acceptor, it was, however, not capable of degrading heptadecane in the absence of oxygen.