Identificação de comunidades bacterianas de solo por seqüenciamento do gene 16S rRNA
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Data
2004-04-07
Autores
Silveira, Érico Leandro da [UNESP]
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Universidade Estadual Paulista (Unesp)
Resumo
Métodos tradicionais de isolamento e cultivo limitam análises da diversidade microbiana no meio ambiente, pois acredita - se que aproximadamente 10% desses microrganismos possam ser cultivados. A ecologia microbiana molecular teve recentes progressos através da construção de bibliotecas metagenômicas, o que constitui uma poderosa abordagem para explorar a diversidade microbiana de solo fornecendo inclusive dados sobre os microrganismos não cultiváveis desse habitat. Este trabalho teve por objetivo comparar e estimar a diversidade de comunidades bacterianas, em solos de duas áreas, sendo solo de Floresta Nativa (SFN) e a outra sob arboreto com eucaliptos (SAE) de uma mesma região. Utilizando oligonucleotídeos iniciadores específicos, o gene 16S rRNA foi amplificado por PCR, os amplicons foram clonados em pGEMR-T e os clones obtidos seqüenciados parcialmente. No solo SFN foram analisados 231 clones e no solo SRE 248 clones. As seqüências obtidas foram submetidas à análise de similaridade de nucleotídeos com o banco de dados GenBank. Os filos bacterianos que mais se destacaram nos dois tipos de solo foram Acidobacteria e Proteobacteria. No solo SFN destacaram-se também as bactérias pertencentes ao filo Bacteroidetes e no solo SAE observou-se alta freqüência das bactérias Actinobacteria. Análises filogenéticas revelaram diferenças em ambos os solos, verificando através de índice de diversidade bacteriana observou-se que o solo sob eucalipto apresentou maior diversidade quando comparado ao solo sob de Floresta Nativa.
Traditional methods of isolation and culture limits the analyses of the microbian diversity in the environment, because it is believed - that approximately 10% of these microrganisms can be cultivated. The molecular microbian ecology have had recent progress through the construction of metagenomics Iibraries, what constitutes a powerful boarding to explore the microbian diversity of soil, also supplying information on the microrganisms that cannot be cultivated on this habitat. This work had the objective of stimate the diversity of bacterial communities, in two areas, an area of Native Forest (SFN) and the another one under eucalypts (SAE) of the same region. Using specific oligonucleotides starters, the gene 16S rRNA was amplified by PCR, amplicons had been cloned in pGEMR-T and the obtained clones were partial/y sequenced. In the soil SFN, 231 clones had been analyzed and 248 clones in the soil SAE. The sequences obtained were submitted to the nucleotides similarity analysis with the GenBank database. The bacterial phylum that was more evident in the two types de soil were Acidobacteria and Proteobacteria. In the soi! SFN the bacteria of the phylum Bacteroidetes were evident and in the soil SRE high frequency of the Actinobacteria bacteria was observed. Phylogenetic analyses reveled an extensive diversity in both soils, verified through diversity index differences in the bacterial communities in both areas, and that the area under eucalypt presented more diversity in relation to the area of Native Forest.
Traditional methods of isolation and culture limits the analyses of the microbian diversity in the environment, because it is believed - that approximately 10% of these microrganisms can be cultivated. The molecular microbian ecology have had recent progress through the construction of metagenomics Iibraries, what constitutes a powerful boarding to explore the microbian diversity of soil, also supplying information on the microrganisms that cannot be cultivated on this habitat. This work had the objective of stimate the diversity of bacterial communities, in two areas, an area of Native Forest (SFN) and the another one under eucalypts (SAE) of the same region. Using specific oligonucleotides starters, the gene 16S rRNA was amplified by PCR, amplicons had been cloned in pGEMR-T and the obtained clones were partial/y sequenced. In the soil SFN, 231 clones had been analyzed and 248 clones in the soil SAE. The sequences obtained were submitted to the nucleotides similarity analysis with the GenBank database. The bacterial phylum that was more evident in the two types de soil were Acidobacteria and Proteobacteria. In the soi! SFN the bacteria of the phylum Bacteroidetes were evident and in the soil SRE high frequency of the Actinobacteria bacteria was observed. Phylogenetic analyses reveled an extensive diversity in both soils, verified through diversity index differences in the bacterial communities in both areas, and that the area under eucalypt presented more diversity in relation to the area of Native Forest.
Descrição
Palavras-chave
Ecologia microbiana, Genetica bacteriana, Reação em cadeia de polimerase, Microbian ecology, Metagenomics
Como citar
SILVEIRA, Érico Leandro da. Identificação de comunidades bacterianas de solo por seqüenciamento do gene 16S rRNA. 2004. ix, 83 f. Dissertação (mestrado) - Universidade Estadual Paulista, Faculdade de Ciências Agrárias e Veterinárias, 2004.