Bioluminescence is a trait observed among different genera and families of bacteria. In this study part of the luxA gene was characterized from the new MS isolates and compared to luxA of other bacteria. The polymerase chain reaction (PCR) was used to amplify a fragment of the luxA gene of strain MS32 and Vibrio harveyi. These fragments were used as probes in hybridization experiments with luminous and nonluminous bacteria. The results from these experiments suggest that some nonluminous species may possess lux like regions in their chromosomal DNA and that luxA probes can demonstrate species identity. The MS32 luxA fragment was also sequenced and used in a phylogenetic analysis to identify the taxonomic affinities of MS strains. It was found that MS1 and MS32 were closely related, however, Shewanella hanedai was not. Thus there was a concordance between the phenotypic and genotypic approaches, which will help in establishing a consistent taxonomic affinity between these bacteria.

Leiognathid fish (Perciformes: Leiognathidae) contain 17 species in Taiwan in three genera: Gaza, Leiognathus, and Secutor. Leiognathid fish form mutualistic bio- luminescent symbiosis with the luminous bacteria Photobacterium leiognathi and have developed a specialized light organ to harbor bacteria and other structures to control light emission. The ecological dependence of leiognathid fish to its symbiont for light production and the specialized adaptations suggest that there co-evolution might have taken place. A single symbiont species were thought to be harbored in the light organ of leiognathid fishes. However, different oxygen rates, light production, and cell morphology have been observed in bacteria culturing during previous studies. To investigate the co-evolutionary interaction between P. leiognathi and leiognathid species, I examined the 2-DE patterns of the outer membrane protein (OMP) of symbiotic bacteria from specimens of five leiognathid species; OMPs have been proposed to be essential in symbiotic interaction. The 2-DE results of the P. leiognathi OMP pattern from five leiognathid species displayed intra-specific similarity, when inter-specific differences also exist. Intra-specific consistence revealed five proteins that are essential in the symbiotic interaction. Spot differences between various leiognathid species have shown that closely related species have significant protein spots which may have effect on speciation. In Secutor ruconius absence of the protein responsible for motility might result the difficulty on bacteria culturing. Intra-specific similarity excludes the possible of individual differentiation, and the inter-specific differences of bacterial OMP suggested that P. leiognathi in various leiognathid species might have developed various OMPs to adapt to different host species.

Orientador: Alexandre Nunes Ponezi / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Civil, Arquitetura e Urbanismo / Made available in DSpace on 2018-08-21T10:44:37Z (GMT). No. of bitstreams: 1 Brota_GiovaniArchanjo_M.pdf: 4346412 bytes, checksum: b44166c5b1e0b8b8123c49c267aa9a87 (MD5) Previous issue date: 2012 / Resumo: O tratamento de esgoto doméstico é de fundamental importância para a manutenção da qualidade dos corpos hídricos e da vida aquática assim como para a conservação dos recursos naturais. Neste foco, os sistemas de tratamento como lagoas de estabilização são largamente utilizados no Brasil para tratamento de efluentes sanitários. O uso de efluente sanitário proveniente do pós-tratamento de lagoa de estabilização utilizado na irrigação de culturas agrícolas é recomendado como prática complementar ao tratamento do efluente, fornecendo assim um aporte de nutrientes necessários ao desenvolvimentos de diversas culturas agrícolas. No entanto essa prática deve ser avaliada quanto aos impactos ambientais. Com esse intuito, foi desenvolvida uma pesquisa para avaliar os potenciais efeitos tóxicos proveniente da aplicação de efluente tratado por lagoas facultativas na cultura de Eucalyptus urograndis. O local escolhido para a pesquisa foi uma área cedida pela ETE Prof. Carmelino Correa Junior (Colégio Agrícola), no município de Franca-SP. A área foi dividida em 8 tratamentos e irrigada de acordo com a dose de "água'' recomendada para a cultura de eucalipto da seguinte forma: T1 dose de Água, sem adubação química, T2 dose de Água, com adubação química, T3 Efluente - 1/3 da dose, com adubação química, T4 Efluente - 1/2 dose com, adubação química, T5 Efluente - 1 dose, com adubação química, T6 Efluente - 1 dose, sem adubação, T7 Efluente - 1,5 dose, sem adubação química e T8 - sem irrigação e sem adubação química (testemunha). A pesquisa avaliou a presença de elementos e compostos com potencial tóxico em detrimento da aplicação de efluente tratado, por meio de analises físicoquímicas e ecotoxicológicas, correlacionando a concentração de metais, sais e o potencial efeito tóxico causado por compostos alelopáticos liberados pelo eucalipto. Assim foi possível inferir a partir dos resultados obtidos nos testes com Daphnia similis e Vibrio fischeri, onde foram obtidos valores de CE50 superiores a 75% para a maior parte dos tratamentos, indicando um baixa toxicidade ou em alguns caso sua ausência / Abstract: The domestic wastewater treatment is critical for maintaining the quality of water bodies and aquatic life as well as for the conservation of natural resources. In this focus, treatment systems and stabilization ponds are widely used in Brazil for the treatment of wastewater. The use of sanitary effluent from the post-treatment stabilization pond used for irrigation of agricultural crops is recommended as a complementary practice to the treatment of the effluent, thus providing a supply of nutrients necessary for the development of several crops. However, this practice should be evaluated for environmental impacts. For this purpose, we developed a survey to assess the potential toxic effects from the application of effluent ponds for the culture of Eucalyptus optional urograndis, the site chosen for the research was an area ceded by Prof. ETE. Carmelino Correa Junior (Agricultural College) in the city of Franca-SP. The area was divided into eight treatments and irrigated according to the dose of "water'' recommended for the cultivation of eucalyptus as follows: T1 dose of water, without chemical fertilizer, T2 dose of water with chemical fertilizer, effluent T3 - third dose, with chemical fertilizer, effluent T4 - 1/2 dose, chemical fertilizer, effluent T5 - 1 dose, with chemical fertilizer, effluent T6 - 1 dose, without fertilization, T7 Effluent - 1.5 dose without chemical fertilizer and T8 - without irrigation and without chemical fertilizer. (control). This study evaluated the presence of elements and compounds with toxic potential detriment of the application of treated wastewater through physical-chemical analyzes and ecotoxicological correlating the concentration of metals, salts and the potential toxic effect caused by allelopathic compounds released from eucalyptus. Thus it was possible to conclude from the results obtained in tests on Daphnia similis and Vibrio fischeri, which were obtained EC50 values higher than 75% for most treatments, indicating a low toxicity and in some cases failing / Mestrado / Saneamento e Ambiente / Mestre em Engenharia Civil

Les biocapteurs optiques ont connu une évolution sans précédent au cours des dernières années, principalement en raison de la forte interaction entre la biotechnologie, l’optique et la chimie des matériaux. Dans cette thèse, deux différentes plates-formes de biocapteurs optiques ont été conçues pour la détection sensible et spécifique des biomolécules. Plus précisément, le premier système de détection optique est construit sur la base de la bioluminescence de cellules bactériennes d'Escherichia coli génétiquement modifiées. L’émission de lumière induite par cette interaction peut donc être utilisée pour la détection des substances toxiques. Le second système utilise des nanoparticules de métaux précieux (or et argent) aux propriétés plasmoniques accordables qui permettent de sonder les interactions des biomolécules spécifiques à l'interface nano-bio par la résonance plasmonique de surface (LSPR). Ces nanoparticules ont été obtenues par traitement thermique à haute température d’un film métallique déposé sur du verre à l’aide d’une grille de TEM ou déposé sur une couche de bactéries fixée sur le verre. Après une optimisation appropriée des nanostructures métalliques en termes de morphologie et de fonctionnalisation, une sensibilité élevée et une grande spécificité peuvent être simultanément obtenues avec ces immunocapteurs plasmonique. Ces deux plateformes ont été utilisées pour détecter des pesticides comme le carbofuran et l’atrazine / Optical biosensors have witnessed unprecedented developments over recent years, mainly due to the lively interplay between biotechnology, optical physics and materials chemistry. In this thesis, two different optical biosensing platforms have been designed for sensitive and specific detection of (bio)molecules. Specifically, the first optical detection system is constructed on the basis of bioluminescence derived from engineered Escherichia coli bacterial cells. Upon stressed by the toxic compounds, the bacterial cells produce light via a range of complex biochemical reactions in vivo and the resulted bioluminescent evolution thus can be used for toxicant detection. The bacterial bioluminescent assays are able to provide competitive sensitivity, while they are limited in the specificity. Therefore, the second optical detection platform is built on the localized surface plasmon resonance (LSPR) immunosensors. In this optical biosensor, the noble metal (gold and silver) nanoparticles with tunable plasmonic properties are used as transducer for probing the specific biomolecules interactions occurred in the nano-bio interface. These nanoparticles were obtained after a high temperature thermal treatment of an initially thin-metallic film deposited on a glass substrate through a TEM grid or on a bacteria layer fixed on the glass. After appropriate optimization on metal nanostructures morphology and surface biomodification, the applicable sensitivity and specificity can be both guaranteed in this LSPR immunosensor