Marine sponges interact and coexist with many different organisms. A two-sponge association between Amphimedon erina and Geodia gibberosa commonly occurs in the Florida Keys. Previous studies have only focused on the ecological influence of the association; they did not examine the cellular basis of the association. This association between A. erina and G. gibberosa was used in the development of an in vitro model to further the understanding of the cellular basis of natural sponge-sponge associations. In this study, sponge cells were cultured individually and in co-cultures and their responses related to apoptosis, cell death, and proliferation were monitored using high content imaging. Co-cultured cells of species that form sponge-sponge associations did not have the same cellular responses compared to co-cultured cells of species that do not form sponge-sponge associations. Protein expression analyses demonstrated that the model that was established does not mimic the cellular response of the association in nature, but this model can be used to test in vitro cellular interactions of sponge species that do not form associations in nature. In addition, the protein expression data that were obtained revealed that sponges use similar apoptotic pathways as humans and suggest that sponge cells may shut down cell cycling in order to repair damaged DNA. This research is a small piece to the puzzle that is sponge cell culture research. / Includes bibliography. / Thesis (M.S.)--Florida Atlantic University, 2017. / FAU Electronic Theses and Dissertations Collection

Micro-organismos são profícuos produtores de produtos naturais bioativos. Diversos fármacos inovativos e de extrema importância clínica são de origem microbiana, como antibióticos, antitumorais, imunossupressores e agentes hipolipêmicos. A maioria dos fármacos de origem microbiana é produzida por actinobactérias. A estreita associação de micro-organismos com plantas, insetos, crustáceos e organismos marinhos, pode induzir a produção de substâncias bioativas, que eventualmente conferem vantagens adaptativas e ecológicas ao macro-organismo hospedeiro. Ambientes marinhos e áreas de transição como os manguezais são ainda pouco explorados para estudos químicos e farmacológicos dos micro-organismos presentes nos solos e em simbiose com outros hospedeiros. Neste sentido, o presente trabalho visou o estudo químico monitorado por ensaios de citotoxicidade em células cancerígenas de dois micro-organismos, Streptomyces sp. Act1 e Streptomyces sp. Act2, isolados da casca do caranguejo do maguezal, Ucides cordatus, coletado em Cananéia, SP. Estes micro-organismos apresentaram atividade antagônica frente ao fungo patogênico Aspergillus niger, confirmando o potencial para produção de substâncias bioativas. Os micro-organismos foram cultivados em diferentes meios de cultura para avaliar o potencial de crescimento, perfil químico dos extratos obtidos e atividade citotóxica dos extratos e subfrações. Os meios de cultura escolhidos foram meio líquido ISP-2 e meio sólido (arroz), e ainda, nestas mesmas condições foi avaliado o efeito do uso de água do mar de forma comparativa. Os micro-organismos desenvolveram-se adequadamente nos diferentes meios de cultivo. Os fracionamentos dos extratos obtidos nos experimentos evidenciaram características polares das subfrações obtidas, e neste sentido foram necessárias adaptações das técnicas de separação, incluindo fases estácionárias como sephadex LH-20 e fase reversa. Os ensaios de citotoxicidade frente às linhagens de células tumorais com os extratos obtidos mostraram o grande potencial das linhagens em estudo, em especial a linhagem Streptomyces sp. Act-2 cultivada na presença de água do mar. / Abstract Microorganisms are prolific producers of bioactive natural products. Most of innovative pharmaceuticals that have useful clinical importance have been isolated from from microorganisms, such as antibiotics, anticancer drugs, immunosuppressive drugs and lipid-lowering agents. Most of the drugs of microbial origin are produced by actinomycetes. The close association of micro-organisms with plants, insects, crustaceans or marine organisms may induce the production of bioactive substances. These natural products may confer adaptive advantages to the environment and to the host organism. Marine and transitional areas such as mangroves are still under explored for chemical and pharmacological studies of both soil microorganisms and symbiotic microorganisms. In this sense, this work aimed a chemical study of two actinobacteria strains, Streptomyces sp. Act1 and Streptomyces sp. Act2, guided by cancer cells cytotoxicity assays. Both microorganisms were isolated from the shell of the mangrove crab Ucides cordatus, collected in Cananéia, SP. These microorganisms showed antagonistic activity against the pathogenic fungus Aspergillus niger, confirming the potential for production of bioactive substances. Microorganisms were cultured in different culture media to assess the potential for growth, chemical profile of extracts and cytotoxic activity of extracts and subfractions. The culture media were chosen using liquid (ISP-2) and solid medium (rice). The effect of addition of saline water in the culture media has also been evaluated. The microorganisms developed adequately in different culture media. The fractions of extracts obtained from the experiments showed characteristics of polar subfractions obtained, requiring the use of sephadex LH-20 and reverse phase as chromatographic stationary phases. Cytotoxic assays of the extracts against cancer cell lines showed the great potential of the strains under study, mainly Streptomyces sp. Act2. grown in the presence of seawater.

Insetos como formigas cortadeiras, cupins e alguns besouros têm sido descritos como agricultores de fungos mutualistas. No entanto, apenas recentemente esse fenômeno foi descrito em abelhas. O objetivo desse trabalho foi estudar os micro-­organismos associados à abelha sem ferrão Scaptotrigona depilis, a primeira abelha agricultora descrita. Foram isolados 149 micro-­organismos a partir de diferentes materiais coletados da colônia, e destes, 28% apresentaram atividade antimicrobiana frente a patógenos humanos. Os micro-­organismos Bacillus sp. SDLI1, Candida sp. SDCP2, Zygosaccharomyces sp. SDBC30G1 e Monascus ruber SDCP1, isolados do favo de cria de S. depilis, foram selecionados para estudo químico e biológico. Foi demonstrado que o fungo-­alimento de S. depilis é Zygosaccharomyces sp., que produz grande quantidade de adipossomos. Os lipídeos e esteroides estocados nessas organelas citoplasmáticas podem ajudar na nutrição larval, uma vez que Zygosaccharomyces sp. é requerido para o desenvolvimento das larvas de S. depilis. Em culturas in vitro de ovos dessa abelha, verificou-­se que ergosterol depempenha papel semelhante ao de Zygosaccharomyces sp. para a metamorfose de S. depilis, indicando que esse mutualista serve como fonte de esteroides para as larvas. Verificou-­se que compostos voláteis produzidos por Candida sp. SDCP2 estimulam o crescimento de Zygosaccharomyces sp. SDBC30G1. Análises revelaram que os compostos voláteis majoritários produzidos por Candida sp. SDCP2 foram etanol (C1) e álcool isoamílico (C2), e essas substâncias também foram encontradas nas células de cria dessa abelha. Já o fungo M. ruber SDCP1 produz lovastatina (M6), um produto natural reconhecido pela inibição da enzima HMG-­CoA redutase, essencial para biossíntese de esteroides, e M6 pode modular o desenvolvimento de Zygosaccharomyces sp. SDBC30G1. Candida sp. SDCP2 estimula a produção de monascinol (M2) e monascina (M3) pelo fungo M. ruber SDCP1 em co-­cultura. Monascina (M3) é ativa frente Candida sp. SDCP2, podendo controlar o crescimento dessa levedura, sendo a produção de M3 aumentada em 57 vezes após sete dias de cocultivo. A investigação química de Bacillus sp. SDLI1 revelou que essa bactéria produz sete surfactinas (B1-­B7) e bacillomicina D (B8), que apresentam atividade antifúngica. O cromossomo circular de Bacillus sp. SDLI1 possui oito clursters biossintéticos para a produção de diferentes classes de antimicrobianos. Bacillus sp. SDLI1 também produz o fago SDLI1-­1, ativo contra Paenibacillus larvae, patógeno causador da cria pútrida americana em Apis mellifera. Cultivos de larvas in vitro revelaram que S. depilis apresenta resistência contra os entomopatógenos Beauveria bassiana e Metarhizium anisopliae, sendo que Bacillus sp. SDLI1 pode desempenhar um papel protetivo para as larvas de S. depilis contra o patógeno P. larvae. Os resultados sugerem que o ambiente encontrado nas colônias de S. depilis favorece o desenvolvimento de uma microbiota especializada. Esses micro-­ organismos interagem e beneficiam a abelha hospedeira, estabelecendo relações de simbiose que devem ser preservadas para a sobrevivência desse polinizador / Some ants, termites and beetles have established mutualistic relationship with fungi that they culture for food. However, just recently a fungus agricultural behavior has been described for bees. The main goal of this study was to investigate the microbiota associated with the stingless bee Scaptotrigona depilis, the first fungus-­ farming bee described. Different materials from S. depilis colony were used to isolate 149 microbial strains, and among these microorganisms, 28% showed antimicrobial activity against human pathogens. The microorganisms Bacillus sp. SDLI1, Candida sp. SDCP2, Zygosaccharomyces sp. SDBC30G1 and Monascus ruber SDCP1, isolated from brood cells of S. depilis, were selected for further studies. Using different approaches, it was confirmed that Zygosaccharomyces sp. SDBC30G1 is the fungus required for S. depilis larval development. This fungus accumulates cytoplasmic lipid droplets that can be a source of sterols and lipids to the larvae. Using in vitro eggs culturing, it was verified that ergosterol, the major sterol produced by Zygosaccharomyces sp. SDBC30G1, can stimulates larval metamorphosis, confirming this yeast as an important sterol source. Co-­cultures provided information about Candida sp. SDCP2 volatile organic compounds (VOCs) production, which stimulates Zygosaccharomyces sp. SDBC30G1 growth. The majoritarian VOCs produced by Candida sp. SDCP2 were ethanol (C1) and isoamyl alcohol (C2), which were also detected in S. depilis brood cells. The fungus M. ruber SDCP1 produces lovastatin (M6), an inhibitor of HMG-­CoA reductase, which can modulate Zygosaccharomyces sp. SDBC30G1 pellicle formation and lipids accumulation. Candida sp. SDCP2 stimulates the production of monascinol (M2) and monascin (M3) by M. ruber SDCP1 in co-­culture. Monascin (M3) is active against Candida sp. SDCP2 and can control the growth of this yeast, once M3 biosynthesis increased ~ 57 folds after seven days of co-­culturing. Bacillus sp. SDLI1 produces seven surfactins (B1-­B7) and bacillomycin D (B8) that presented antifungal activity against pathogenic fungi. This bacterium had its whole-­genome sequenced and the circular chromosome harbors biosynthetic gene clusters to produce eight classes of antimicrobial compounds. The phage SDLI1-­1, which presented activity against Paenibacillus larvae, a pathogen causative of American Foulbrood Disease, was also produced by Bacillus sp. SDLI1. S. depilis larvae were resistant against Beauveria bassiana and Metarhizium anisopliae infections, and Bacillus sp. SDLI1 was capable to increase larval survival during in vitro culturing with P. larvae. The results suggest that the environmental conditions found in S. depilis colonies favor the development of a specialized microbiota. These microorganisms interact and produce beneficial factors to its host. These stablished symbiotic relationships contribute with the homeostasis inside the colony and they must be preserved to safeguard S. depilis survival

O cenário de grandes transformações do mundo atual fez com que autores consagrados como C. K. Prahalad, Gary Hamel e Peter F. Drucker reconhecessem que os modelos estratégicos vigentes estariam encontrando dificuldades para oferecer racionalidades adequadas para se lidar com o problema da mudança nas sociedades e nas organizações de produção contemporâneas. Para parcela significativa da produção científica recente na área, a problemática em tela se deve, em grande medida, à fragmentação teórica e à especialização decorrente do uso intensivo de abordagens prescritivas nas Ciências Administrativas. Este cenário conduz à necessidade de se repensar os correntes arcabouços conceituais. Neste sentido, o presente esforço de pesquisa tem por objetivo desenvolver uma sintetize dos aspectos internos e externos da dinâmica do problema estratégico, a partir de abordagens aderentes à teoria da Complexidade. Para tal, foi realizado um esforço de revisão conceitual embasado em análise do problema, segundo a metodologia fenomenológica de Husserl. Os resultados foram submetidos a um procedimento analógico realizado por meio de pesquisa bibliográfica nas literaturas que tratam da complexidade em outros sistemas teóricos próprios, especialmente os da Biologia. Como resultado, identificou-se que as organizações são produto de acoplamentos entre dois ou mais sistemas distintos que, por sua vez, se acoplam ao sócio-sistema humano e estes, por sua vez, ao restante da dinâmica planetária. Em última análise, esta configuração nutre forte analogia com as dinâmicas baseadas na simbiose, encontradas nos estudos mais recentes da biologia que, ao que o estudo indica, podem se transformar em uma inspiradora, importante e útil analogia para o aperfeiçoamento dos arcabouços teóricos em gestão estratégia. / Major Changes in today´s world has made renowned authors such as C. K. Prahalad, Gary Hamel and Peter F. Drucker recognized that the existing strategic models are not providing reasonable and adequate solutions to deal with the society changing problems and with the contemporary production organizations. For a significant portion of the recent scientific output in this area, the issue faced is due to, in most of it, the theoretical fragmentation and the specialization resulting from the intensive use of prescriptive approaches in Administrative Sciences. This scenario leads to the need of rethinking the current conceptual frameworks. This study, in particular, addresses the concepts related to the strategic problem of which we highlight the dynamics behind the problem, results of the aforementioned organizational changes which are characteristic of a contemporary society. For this, the present research effort aims to develop a summarized study of the internal and external aspects of dynamic strategic problems and, taking as a starting point the approaches inherent in the complexity theory. To achieve this, an effort was made to review the concept behind the problem analysis, according to Husserl´s phenomenological methodology. The results were submitted to an analog procedure, bibliographical research on the literatures that deals with complexity in other theoretical systems, especially in biology. As a result, it was found that organizations are products of couplings between two or more separate systems, which will couple to the socio-­human system, and these, to the rest of the planetary dynamics. As a last analysis, this configuration has strong analogy with the dynamics based on symbiosis, found in recent biology; this study suggests that it can become an inspiring, important and useful metaphor for the improvement of the theoretical frameworks in management strategy.

A associação simbiótica entre a diatomácea cêntrica Chaetoceros coarctatus e o ciliado peritríquio Vorticella oceanica é amplamente conhecida e registrada em diversos estudos, porém nunca havia sido analisada sob o ponto de vista de suas implicações para o movimento destes organismos. A fim de contribuir com novos dados acerca desta associação simbiótica, o presente trabalho analisou a relevância ecológica da simbiose entre Chaetoceros e Vorticella, por meio de um estudo comportamental do deslocamento destes organismos na coluna de água. As associações foram coletadas em águas costeiras de Ubatuba, São Paulo, onde sua ocorrência foi observada em elevada abundância, particularmente durante o verão. Utilizando técnicas de imagem de alta frequência em um sistema óptico tridimensional foi possível descrever os padrões de deslocamento desta associação e avaliar as implicações ecológicas deste comportamento. De acordo com as análises realizadas neste trabalho, pode-se sugerir que o comportamento de deslocamento realizado pela associação Chaetoceros-Vorticella na coluna de água resulta em vantagens tanto para o epibionte quanto para o hospedeiro. Em termos de submesoescala, este estudo sugere que o deslocamento realizado pela associação Chaetoceros-Vorticella pode contribuir para a formação de camadas finas, levando à formação de hotspots de atividade biogeoquímica e interações tróficas no ecossistema pelágico. / The symbiotic association between the centric diatom Chaetoceros coarctatus and the peritrich ciliate Vorticella oceanica is widely known and reported in several studies, but its implications for the movement of these organisms have never been analyzed. In order to contribute with new data about this symbiotic association, the present study investigated the ecological relevance of the Chaetoceros-Vorticella association by recording displacement parameters of these organisms in the water column. The associations were collected in coastal waters of Ubatuba, São Paulo, where their occurrence was observed in high abundance, particularly during the summer. Using high-resolution imaging techniques in a three dimensional optical system it was possible to describe the displacement patterns of this association and to provide initial insights about the ecological implications of this behavior. It is suggested that the displacement behavior performed by the Chaetoceros-Vorticella association in the water column is beneficial for both the epibiont and the host. In terms of submesoscale processes, this study indicates that the displacement carried out by the Chaetoceros-Vorticella association may contribute to the formation of thin layers, leading to the formation of hotspots of biogeochemical activity and trophic interactions in the pelagic ecosystem.

A associação simbiótica entre a diatomácea cêntrica Chaetoceros coarctatus e o ciliado peritríquio Vorticella oceanica é amplamente conhecida e registrada em diversos estudos, porém nunca havia sido analisada sob o ponto de vista de suas implicações para o movimento destes organismos. A fim de contribuir com novos dados acerca desta associação simbiótica, o presente trabalho analisou a relevância ecológica da simbiose entre Chaetoceros e Vorticella, por meio de um estudo comportamental do deslocamento destes organismos na coluna de água. As associações foram coletadas em águas costeiras de Ubatuba, São Paulo, onde sua ocorrência foi observada em elevada abundância, particularmente durante o verão. Utilizando técnicas de imagem de alta frequência em um sistema óptico tridimensional foi possível descrever os padrões de deslocamento desta associação e avaliar as implicações ecológicas deste comportamento. De acordo com as análises realizadas neste trabalho, pode-se sugerir que o comportamento de deslocamento realizado pela associação Chaetoceros-Vorticella na coluna de água resulta em vantagens tanto para o epibionte quanto para o hospedeiro. Em termos de submesoescala, este estudo sugere que o deslocamento realizado pela associação Chaetoceros-Vorticella pode contribuir para a formação de camadas finas, levando à formação de hotspots de atividade biogeoquímica e interações tróficas no ecossistema pelágico. / The symbiotic association between the centric diatom Chaetoceros coarctatus and the peritrich ciliate Vorticella oceanica is widely known and reported in several studies, but its implications for the movement of these organisms have never been analyzed. In order to contribute with new data about this symbiotic association, the present study investigated the ecological relevance of the Chaetoceros-Vorticella association by recording displacement parameters of these organisms in the water column. The associations were collected in coastal waters of Ubatuba, São Paulo, where their occurrence was observed in high abundance, particularly during the summer. Using high-resolution imaging techniques in a three dimensional optical system it was possible to describe the displacement patterns of this association and to provide initial insights about the ecological implications of this behavior. It is suggested that the displacement behavior performed by the Chaetoceros-Vorticella association in the water column is beneficial for both the epibiont and the host. In terms of submesoscale processes, this study indicates that the displacement carried out by the Chaetoceros-Vorticella association may contribute to the formation of thin layers, leading to the formation of hotspots of biogeochemical activity and trophic interactions in the pelagic ecosystem.

This thesis sets out a model to examine how the internet functions. 'The symbiotic web' suggests a symbiotic relationship between corporations that have built business models dependent upon the gathering of personal data from people, and the individuals themselves who have begun to rely on apparently 'free' services (from search to email, social networking to YouTube). Having set out the model, the thesis looks at its implications: how it has contributed to many, both the positive and negative, developments on the internet in recent years, but also driven the mass gathering, use and holding of personal data. The symbiotic web is currently essentially beneficial to both businesses and individuals, but there are significant risks attached - risks associated with the accumulation of data and risks that the symbiotic relationship could become negative and parasitic, putting individuals' privacy and autonomy at risk. The implications of this model are examined through the use of case studies: the dispute between Google and the Article 29 Working Party over data retention, Phorm's 'Webwise' behavioural targeting system, and a number of smaller case studies about data vulnerability from the HMRC data disc loss to the ACS:Law hack/leak. The thesis suggests the development and use of specific rights designed for the internet to address the associated risks: a 'right to roam the internet with privacy', a right to monitor those who monitor us, and a 'right to delete data'. These rights would be set out as principles rather than enacted and enforced as laws, and brought into play through Murray's model of symbiotic regulation. These rights would support the positive development of the web symbiosis and encourage and shape new business models that are more supportive of individual autonomy and privacy.

Les Bradyrhizobium photosynthétiques sont capables d'induire la formation de nodules fixateurs d'azote chez certaines légumineuses du genre Aeschynomene. La découverte récente que certaines de ces souches ne possèdent pas les gènes canoniques nodABC indique l'existence d'un nouveau processus symbiotique rhizobium-légumineuse indépendant des facteurs Nod. L'objectif de ce travail de thèse a consisté à avancer dans la compréhension des mécanismes mis en jeu lors de cette nouvelle interaction. Dans un premier temps, à travers différentes approches cytologiques, le processus par lequel la bactérie infecte la plante en l'absence de facteurs Nod a été décrit. Dans un deuxième temps, afin de mettre en évidence les bases moléculaires de cette interaction, une banque de 15 000 mutants Tn5 de la souche ORS278 a été criblée sur plante. Ce criblage a permit l'identification de plus d'une centaine de gènes bactériens intervenant durant le processus symbiotique. Les résultats obtenus nous ont conduits à proposer un modèle dans lequel la mise en place de la symbiose Nod-indépendante impliquerait, d'une part, la synthèse bactérienne d'une cytokinine permettant le déclenchement de l'organogenèse nodulaire, et d'autre part, d'autres signaux bactériens intervenant dans l'étape de reconnaissance avec la plante hôte. Enfin, nous avons mis en place une technique de transformation génétique d'Aeschynomene et validé cet outil à travers l'étude de l'expression hétérologue de la noduline précoce MtENOD11. Il peut à présent être envisagé de conduire des études fonctionnelles sur Aeschynomene en vue de caractériser la voie de signalisation Nod-indépendante. / The photosynthetic Bradyrhizobium are able to induce the formation of nitrogen-fixing nodules in some legumes of the Aeschynomene genus. The recent discovery that some of these strains lack the canonical nodABC genes indicates the existence of a new symbiotic rhizobium-legume process that is independent of Nod factors. The aim of this work was to improve our understanding of the mechanisms involved in this new interaction. First, through various cytological approaches, the process by which the bacterium infects the plant in the absence of Nod factors has been described. Second, in order to decipher the molecular basis of this interaction, a library of 15,000 Tn5 mutants of the ORS278 strain was screened on plant. This screening allowed the identification of about one hundred bacterial genes involved in this symbiotic process. These results led us to propose a model in which the establishment of the Nod-independent symbiosis involves, on one han d, the synthesis of a bacterial cytokinin that triggers nodule organogenesis, and on the other hand, others bacterial signals that permit the recognition with the host plant. Finally, we developed a genetic transformation procedure of Aeschynomene and we validated this tool by studying the heterologous expression of the early nodulin MtENOD11. Now, functional studies on Aeschynomene are possible to permit the characterization of the Nod-independent signaling pathway.

La crevette hydrothermale Rimicaris exoculata est une espèce endémique des sites hydrothermaux de la ride médio-atlantique (MAR). Cette espèce vit en agrégats denses sur les parois des cheminées hydrothermales actives et domine la mégafaune de la plupart de ces sites. Cette crevette abrite deux communautés microbiennes distinctes dont les rôles demeurent partiellement élucidés. Une de ces communautés est associée à la cavité céphalothoracique et aux pièces buccales hypertrophiées. Celles-ci sont recouvertes par une importante communauté épibionte correspondant à des bactéries chimioautotrophes associées à des dépôts minéraux. Afin d’approfondir notre connaissance de cette communauté symbiotique et dans le cadre de la thèse, une approche de métagénomique a été entreprise.Celle-ci a permis de mettre en évidence la diversité microbienne présente, avec un phylum dominant, celui des Protéobactéries. Au sein de ce phylum, deux classes sont dominantes, les Gamma- et les Epsilonproteobacteria, d’autres classes sont également présentes, les Alpha-, Delta- et Beta-proteobacteria.Une nouvelle classe de Protéobactéries, les Zetaproteobacteria, très récemment décrite comme bactéries libres dans l'environnement hydrothermal, a été mise en évidence. Les types métaboliques bactériens ont également pu être étudiés de façon plus approfondie permettant d’avancer encore davantage dans la compréhension de la symbiose entre la crevette et les microorganismes s’y développant. Il a notamment été possible de reconstituer des voies métaboliques entières pour chaque épibionte principal (à savoir Epsilon-et Gammaproteobacteria) ainsi que d'étudier des gènes impliqués notamment dans la réponse aux fluctuations environnementales, dans la communication cellulaire et le quorum-sensing. Le groupe des Zetaproteobacteria a également été étudié, tout d'abord dans le cadre de l'analyse métagénomique, mais également par des approches moléculaires sur des spécimens provenant de plusieurs sites hydrothermaux de la MAR, et ce, afin de mieux définir l'association possible entre ces bactéries ferro-oxydantes et R. exoculata. La seconde communauté associée à R. exoculata réside dans le tractus digestif. Des analyses complémentaires aux précédentes études ont été menées lors de ce travail de thèse combinant notamment approche métagénomique et culturale. / The hydrothermal shrimp Rimicaris exoculata is an endemic species of the Mid-Atlantic Ridge (MAR).This species lives in dense aggregates on the walls of active chimneys and dominates the megafauna of most of these sites. This shrimp has two distinct microbial communities whose roles remain almost unknown. One of these communities is associated with the cephalothorax and hypertrophied mouthparts.These are covered by a dense community of bacteria affiliated to chemoautotrophic epibionts associated with mineral deposits. To deepen our knowledge on the symbiotic community in the context of the thesis, a metagenomic approach was undertaken. This helped highlighting the microbial diversity present with a dominant phylum, the Proteobacteria. Two classes are dominant, Gamma-and Epsilonproteobacteria, other classes are also present. A new class of Proteobacteria, the Zetaproteobacteria very recently described as free living in hydrothermal environments, was identified. Bacterial metabolic types have also been studied in more detail via the metagenome to advance further in the understanding of the symbiosis. It has been possible to reconstruct metabolic pathways for each main epibiont (i.e. Epsilon- and Gammaproteobacteria), and to study genes in response to environmental fluctuations, in cell communication and quorum-sensing. The Zetaproteobacteria group has also been studied, first in the context of metagenomic analysis, but also using molecular approaches on several specimens from the MAR hydrothermal sites, to better define the possible association between R. exoculata and iron-oxidizing bacteria. The second community associated with R. exoculata is located in the digestive tract. Additional analyzes to previous studies have been conducted in this thesis including a metagenomic approach and cultures.

Esta tese é o resultado de uma extensa investigação a respeito do processo criativo pessoal que envolve a invenção de um ecossistema como poética artística. Ela é a resposta para a possibilidade de construir uma poética visual coerente baseada nos conceitos biológicos de ecossistema e simbiose que envolva construções escultóricas a partir de objetos cotidianos banais de pequeno tamanho, encontrados principalmente no ambiente doméstico. Baseada nas experiências pessoais prévias, dedicadas ao objeto na arte, e focada na busca por objetos comuns passíveis de produzirem interação simbiótica foi construído um conjunto de trabalhos envolvendo objetos, fotografias, pessoas e o espaço, os quais foram ordenados para melhor identificação segundo suas características quanto ao suporte e ao procedimento técnico. São eles: a) conjuntos simbióticos verticais, que podem ser compartimentados, livres ou mistos - aqueles cujo substrato de apoio é vertical como a parede; b) conjuntos simbióticos horizontais - aqueles cujo substrato de apoio é horizontal; c) trabalhos fotográficos - trabalhos originados a partir da fotografia e, d) trabalhos macro visíveis - trabalhos confeccionados a partir de lentes ou que as requerem para melhor serem vistos. A partir de organizações de montagem intencionadas para proporcionar maior proximidade e intimidade do espectador através de movimentos do corpo, os trabalhos instigam a percepção da escala das coisas bem como dá vistas aos objetos ínfimos imperceptíveis no cotidiano. A articulação teórico-prática acontece levando-se em conta diferentes estudos relacionados ao objeto principalmente na voz de Abraham Moles, Jean Baudrillard e Gaston Bachelard. Além de dialogar com designers e diversos artistas cujas obras tangenciam aspectos desta pesquisa, articulamos reflexões com o pensamento do curador Agnaldo Farias sobre o objeto na arte contemporânea. Defendemos que o lugar para pequenos objetos no contexto da arte contemporânea é um ecossistema inventado no qual o espectador é convidado a interagir e deixar-se levar por sua fantasia e imaginação da mesma maneira que somos conquistados pelas palavras e imagens de um livro infantil. / This Thesis is the result of an extensive investigation of the personal creative process involving the invention of an ecosystem as artistic poetics. It is the answer to the possibility of building a coherent visual poetics based on biological concepts of ecosystem and symbiosis, involving sculptural constructions from banal daily objects of small size, mainly found at home. Based on previous personal experiences, dedicated to the object in art and focused on the search for common objects capable to produce symbiotic interaction, I built a body of work involving objects, photographs, people and space, which were ordered for better identification according to their characteristics of support and technical procedure. They are a) vertical symbiotic sets, which may be compartmentalized, free or mixed - those works whose substrate support is vertical as the wall; b) horizontal symbiotic sets - those works whose substrate support is horizontal; c) photographic works - works originating from photography; and d) macro visible work - work made from lenses or require them to best be displayed. From intentioned assembly organizations to provide greater closeness and intimacy of the spectator through body movements, the work instigate the perception of things scale and gives views to tiny inconspicuous objects in daily life. The theoretical and practical articulation occurs taking into account different studies related to the object mainly in the thinking of Abraham Moles, Jean Baudrillard and Gaston Bachelard. In addition of dialogue with designers and several artists whose works tangent aspects of this research, I articulate reflections with the thought of the curator Agnaldo Farias about the object in contemporary art. I argue that the place for small objects in the context of contemporary art is an ecosystem created, in which the spectator is invited to interact and let themselves be taken away by their fantasy and imagination in the same way that we are conquered by the words and images of a children's book.