| Summary: | Submitted by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-09-08T13:51:47Z
No. of bitstreams: 1
OtavioHenriqueB.PintoDissertacao2017.pdf: 3191289 bytes, checksum: b7b005d77190f465fe0685851ff5f090 (MD5) === Approved for entry into archive by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-09-08T13:52:01Z (GMT) No. of bitstreams: 1
OtavioHenriqueB.PintoDissertacao2017.pdf: 3191289 bytes, checksum: b7b005d77190f465fe0685851ff5f090 (MD5) === Made available in DSpace on 2017-09-08T13:52:02Z (GMT). No. of bitstreams: 1
OtavioHenriqueB.PintoDissertacao2017.pdf: 3191289 bytes, checksum: b7b005d77190f465fe0685851ff5f090 (MD5)
Previous issue date: 2017-03-29 === 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. === Acidobacteria ?? um dos filos mais abundantes no solo, entretanto, n??o se conhece as raz??es que levam a essa abund??ncia. Estudos indicam que essa caracter??stica pode ser devido a mecanismos de resist??ncia e a grande quantidade de glicosil hidrolases e transferases presentes em Acidobacteria. Assim, esse estudo teve como objetivo investigar mecanismos de resist??ncia que podem contribuir para a abund??ncia de Acidobacteria no solo. Al??m disso, foi investigada a degrada????o de celulose em Acidobacteria, procurando entender sua participa????o em processos de degrada????o de material originado de plantas. Neste estudo foi utilizado como modelo Occallatibacter savannae AB23. Este isolado foi caracterizado taxonomicamente e foram avaliadas a degrada????o de celulose e produ????o de caroten??ides. A degrada????o de celulose foi avaliada utilizando-se carboximetilcelulose (CMC). Para os pigmentos, foram identificados quais carotenoides essa bact??ria produz e os est??mulos que levam a sua produ????o. Os resultados mostraram que o isolado AB23 consegue assimilar CMC, no entanto de uma forma muito lenta, sendo necess??rios 2 meses para a visualiza????o de col??nias. Para este isolado, as endoglucanasases foram encontradas associadas ?? fra????o celular da cultura. Al??m disso, celobiose mostrou ser um repressor e a lactose um indutor da express??o de endocglucanases. Foi poss??vel observar a produ????o de pigmentos em AB23. Por espectrometria de massa, foi poss??vel encontrar ??ons relacionados aos carotenoides: ??-caroteno, neurosporeno, licopeno, ??-caroteno, ??-caroteno, fitoeno e fitoflueno. Estes devem estar sendo empregados como um mecanismo de resist??ncia, uma vez que eles s??o produzidos em resposta ao estresse causado pela luz. No entanto a presen??a de vitaminas, oxig??nio e elementos tra??o s??o essenciais para produ????o desses pigmentos. As caracter??sticas encontradas neste trabalho podem ser um dos mecanismos de persist??ncia e/ou resist??ncia que conferem abund??ncia para Acidobacteria no solo.
|
|---|
