• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 2
  • Tagged with
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Metagen?mica comparativa de solo de regi?es de mata atl?ntica e caatinga do estado do Rio Grande do Norte - Brasil

Pacchioni, Ralfo Goes 02 December 2010 (has links)
Made available in DSpace on 2014-12-17T14:03:36Z (GMT). No. of bitstreams: 1 RalfoGP_DISSERT_partes_autorizadas.pdf: 608925 bytes, checksum: dbfcce5de284f89c5cdaee179cdd9bc2 (MD5) Previous issue date: 2010-12-02 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / The microorganisms play very important roles in maintaining ecosystems, which explains the enormous interest in understanding the relationship between these organisms as well as between them and the environment. It is estimated that the total number of prokaryotic cells on Earth is between 4 and 6 x 1030, constituting an enormous biological and genetic pool to be explored. Although currently only 1% of all this wealth can be cultivated by standard laboratory techniques, metagenomic tools allow access to the genomic potential of environmental samples in a independent culture manner, and in combination with third generation sequencing technologies, the samples coverage become even greater. Soils, in particular, are the major reservoirs of this diversity, and many important environments around us, as the Brazilian biomes Caatinga and Atlantic Forest, are poorly studied. Thus, the genetic material from environmental soil samples of Caatinga and Atlantic Forest biomes were extracted by direct techniques, pyrosequenced, and the sequences generated were analyzed by bioinformatics programs (MEGAN MG-RAST and WEBCarma). Taxonomic comparative profiles of the samples showed that the phyla Proteobacteria, Actinobacteria, Acidobacteria and Planctomycetes were the most representative. In addition, fungi of the phylum Ascomycota were identified predominantly in the soil sample from the Atlantic Forest. Metabolic profiles showed that despite the existence of environmental differences, sequences from both samples were similarly placed in the various functional subsystems, indicating no specific habitat functions. This work, a pioneer in taxonomic and metabolic comparative analysis of soil samples from Brazilian biomes, contributes to the knowledge of these complex environmental systems, so far little explored / Os microorganismos desempenham importantes fun??es na manuten??o dos ecossistemas, o que explica o enorme interesse em compreender as rela??es existentes entre estes organismos, bem como entre eles e o meio. Estima-se que o n?mero total de c?lulas procari?ticas na Terra seja entre 4 e 6 x 1030, constituindo um enorme pool biol?gico e gen?tico a ser explorado. Apesar de atualmente apenas 1% de toda essa riqueza poder ser cultivada por t?cnicas laboratoriais padr?o, ferramentas metagen?micas permitem o acesso ao potencial gen?mico de amostras ambientais de forma independente de cultivo, e em associa??o com tecnologias de sequenciamento da terceira gera??o, a cobertura amostral se torna ainda maior. Solos, em particular, s?o os maiores reservat?rios dessa diversidade, e muitos ambientes importantes ao nosso redor, como os biomas brasileiros Caatinga e Mata Atl?ntica, s?o pouco estudados. Sendo assim, o material gen?tico ambiental de amostras de solo dos biomas Caatinga e Mata Atl?ntica foi extra?do atrav?s de t?cnicas diretas, pirosequenciado, e as seq??ncias geradas foram analisadas atrav?s de programas de bioinform?tica (MEGAN, MG-RAST e WEBCarma). Perfis taxon?micos comparativos das amostras mostraram que os filos Proteobacteria, Actinobacteria, Acidobacteria e Planctomycetes foram os mais representativos. Em adi??o, fungos do filo Ascomycota foram identificados predominantemente na amostra de solo de Mata Atl?ntica. Perfis metab?licos mostraram que, apesar da exist?ncia de diferen?as ambientais, sequ?ncias de ambas as amostras foram inseridas similarmente nos diversos subsistemas funcionais, n?o indicando fun??es habitat espec?ficas. Este trabalho, pioneiro em an?lises taxon?micas e metab?licas comparativas de amostras de solo de biomas brasileiros, contribui para o conhecimento destes sistemas ambientais complexos, at? ent?o pouco explorados
2

Metagenoma de comunidades microbianas expostas ? radia??o natural e a metais

Ferreira, Henrique C?sar de Jesus 25 September 2014 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2015-12-15T17:45:11Z No. of bitstreams: 1 HenriqueCesarDeJesusFerreira_DISSERT.pdf: 3079036 bytes, checksum: 669ef1f5f7345e06f0db2159cfbc3fcd (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2015-12-29T20:46:40Z (GMT) No. of bitstreams: 1 HenriqueCesarDeJesusFerreira_DISSERT.pdf: 3079036 bytes, checksum: 669ef1f5f7345e06f0db2159cfbc3fcd (MD5) / Made available in DSpace on 2015-12-29T20:46:40Z (GMT). No. of bitstreams: 1 HenriqueCesarDeJesusFerreira_DISSERT.pdf: 3079036 bytes, checksum: 669ef1f5f7345e06f0db2159cfbc3fcd (MD5) Previous issue date: 2014-09-25 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico - CNPq / Muitas esp?cies se especializaram em viver nos mais variados ambientes existentes demonstrando a not?vel capacidade de adapta??o do mundo microbiano as mais diversas condi??es f?sico-qu?micas. Ambientes expostos ? radia??o natural e a metais s?o escassos ao redor do mundo, apresentando uma microbiota ainda desconhecida. Com um n?mero total estimado entre 4 e 6 x 1030 microrganismos na terra, estes constituem um enorme pool biol?gico e gen?tico a ser explorado. Abordagens metagen?micas, independentes de cultivo, proporcionam uma nova forma de acesso ao potencial gen?mico de amostras ambientais tornando-se uma importante ferramenta para elucida??o de fun??es ecol?gicas, bem como para identifica??o de novas esp?cies e biomol?culas. Neste trabalho, o material gen?tico ambiental de amostras de solo e ?gua do A?ude Boqueir?o de Parelhas-RN, sob influ?ncia de radia??o natural e da presen?a de metais, foi extra?do, pirosequenciado, e as sequ?ncias geradas foram analisadas atrav?s de programas de bioinform?tica (MG-RAST e STAMP). Perfis taxon?micos comparativos de ambas as amostras mostraram alta abund?ncia do Dom?nio Bacteria, seguida por uma pequena parcela atribu?da aos Dom?nios Eucaryota, Archaea e V?rus. Proteobacteria, Actinobacteria e Bacterioidetes foram os filos que mostraram maior domin?ncia em ambas as amostras. Importantes g?neros e esp?cies associados ? resist?ncia aos agentes estressores encontrados na regi?o foram observados. Sequ?ncias relacionadas ? replica??o e reparo do DNA, ao estresse oxidativo e estresse pelo calor e a resist?ncia a compostos t?xicos foram observadas, mostrando uma importante rela??o entre a microbiota e seu perfil metab?lico, influenciada pelas vari?veis ambientais regionais. Os resultados encontrados neste estudo adicionam valiosos e in?ditos dados sobre a composi??o de comunidades microbianas nestas regi?es. / Many species have specialized to live in the most varied existing environments showing the remarkable adaptability of the microbial world the most diverse physicochemical conditions. Environments exposed to natural radiation and metals are scarce around the world, presenting a microbiota still unknown. With a total number estimated between 4 and 6 x 1030 microrganisms on earth, they constitute an enormous biological and genetic pool to be explored. Metagenomic approach independent of cultivation, provides a new form to access to the potential genomic environmental samples becoming a powerful tool for the elucidation of ecological functions, metabolic profiles, as well as to identify new biomolecules. In this context, the genetic material of environmental soil and water samples from A?ude Boqueirao Parelhas-RN, under the influence of natural radiation and the presence of metals, was extracted, pirosequencing and the generated sequences were analyzed by bioinformatics programs (MG-RAST and STAMP). Taxonomic comparative profiles of both samples showed high abundance of Domain Bacteria, followed by a small portion attributable to Eucaryota Domains, Archaea and Viruses. Proteobacteria, Actinobacteria and Bacterioidetes phyla showed the greater dominance in both samples. Important genera and species associated with resistance to various stressors found in region were observed. Sequences related to oxidative and heat stress, DNA replication and repair, and resistance to toxic compounds were observed, suggesting a significant relationship between the microbiota and their metabolic profile, influenced by regional environmental variables. The results of this study add valuable and unpublished data on the composition of microbial communities in these regions
3

The Search for Novel Sponge genes: Comparative Analysis of Gene Expression in Multiple Sponges

Burkhart, Tandace L. 31 July 2012 (has links)
This project focuses on the use of sponge genetic transcripts in the form of expressed sequence tags (ESTs) readily available in Genbank to search for novel genes using bioinformatics analysis tools. Marine sponge species are known to house a diversity of marine microbes and are known as the ‘living fossils’ of the animal kingdom because of the large number of ancient genes they house. Genomic mining can be a useful tool in discovering these orthologous genes. This study utilized the techniques of genomic mining of 11 previously described sponge species transcripts. The results of this study provide a better understanding of the genomic structure of the organisms studied by creating a more detailed genetic map and examining a specific environmental snapshot of the genes in each sponge. Novel methods for dissecting beneficial information from large scale data sets available in genomic libraries utilizing bioinformatics search tool MGRAST were examined. The results of this study indicate that sponges house numerous genes that are likely to be evolutionary predecessors of genes in higher eukaryotes. Support was also given to the notion that microbial communities play a role in metabolic pathways of sponges.

Page generated in 0.0104 seconds