Detalhes bibliográficos
| Ano de defesa: |
2017 |
| Autor(a) principal: |
Pinto, Ot??vio Henrique Bezerra
 |
| Orientador(a): |
Barreto, Cristine Chaves
|
| Banca de defesa: |
Não Informado pela instituição |
| Tipo de documento: |
Dissertação
|
| Tipo de acesso: |
Acesso aberto |
| Idioma: |
por |
| Instituição de defesa: |
Universidade Cat??lica de Bras??lia
|
| Programa de Pós-Graduação: |
Programa Strictu Sensu em Ci??ncias Gen??micas e Biotecnologia
|
| Departamento: |
Escola de Sa??de e Medicina
|
| País: |
Brasil
|
| Palavras-chave em Português: |
|
| Área do conhecimento CNPq: |
|
| Resumo em Inglês: |
Acidobacteria is one of the most abundant phyla in soil; however, it is not yet known the reasons for their success in terrestrial habitats. This characteristic may be due to mechanisms of resistance as well as the large amount of glycosyl hydrolases and transferases present in Acidobacteria. Therefore, this study aimed to investigate mechanisms of resistance that may contribute to the abundance of Acidobacteria in soil. In addition, the degradation of cellulose was investigated, to understand its participation in processes of plant biomass degradation. In this study, a member of subdivision 1 of Acidobacteria, Occallatibacter savannae AB23 was used as model. This isolate was taxonomically characterized and cellulose degradation and carotenoid production were evaluated. The degradation of cellulose was evaluated using carboxymethylcellulose (CMC). The pigments were identified since this bacterium produced several carotenoids under different environmental stimuli. The results showed that the isolate AB23 can assimilate CMC, however in a very slow way, requiring 2 months for the visualization of colonies and 1 year to visualization of biomass in liquid medium. For this isolate, endoglucanases were found associated with the cell fraction of culture. In addition, cellobiose has been shown to be a repressor and lactose an inducer of endoglucanases expression. It was possible to observe the production of carotenoids in AB23. By mass spectrometry, it was possible to find ions related to carotenoids: ?? -carotene, neurosporene, lycopene, ??-carotene, ??-carotene, phytoene and phytofluene. These carotenoids might be used as a resistance mechanism since they are produced in response to stress caused by light. However, the presence of vitamins, oxygen and trace elements are essential for carotenoid production. The characteristics found in this work may be one of the mechanisms of persistence and / or resistance that confer abundance for Acidobacteria in soil. |
| Link de acesso: |
https://bdtd.ucb.br:8443/jspui/handle/tede/2271
|
Resumo: |
Acidobacteria is one of the most abundant phyla in soil; however, it is not yet known the reasons for their success in terrestrial habitats. This characteristic may be due to mechanisms of resistance as well as the large amount of glycosyl hydrolases and transferases present in Acidobacteria. Therefore, this study aimed to investigate mechanisms of resistance that may contribute to the abundance of Acidobacteria in soil. In addition, the degradation of cellulose was investigated, to understand its participation in processes of plant biomass degradation. In this study, a member of subdivision 1 of Acidobacteria, Occallatibacter savannae AB23 was used as model. This isolate was taxonomically characterized and cellulose degradation and carotenoid production were evaluated. The degradation of cellulose was evaluated using carboxymethylcellulose (CMC). The pigments were identified since this bacterium produced several carotenoids under different environmental stimuli. The results showed that the isolate AB23 can assimilate CMC, however in a very slow way, requiring 2 months for the visualization of colonies and 1 year to visualization of biomass in liquid medium. For this isolate, endoglucanases were found associated with the cell fraction of culture. In addition, cellobiose has been shown to be a repressor and lactose an inducer of endoglucanases expression. It was possible to observe the production of carotenoids in AB23. By mass spectrometry, it was possible to find ions related to carotenoids: ?? -carotene, neurosporene, lycopene, ??-carotene, ??-carotene, phytoene and phytofluene. These carotenoids might be used as a resistance mechanism since they are produced in response to stress caused by light. However, the presence of vitamins, oxygen and trace elements are essential for carotenoid production. The characteristics found in this work may be one of the mechanisms of persistence and / or resistance that confer abundance for Acidobacteria in soil. |
