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| Author(s): |
Juliana Eschholz de Araujo
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Piracicaba. |
| Institution: | Universidade de São Paulo (USP). Escola Superior de Agricultura Luiz de Queiroz (ESALA/BC) |
| Defense date: | 2014-04-14 |
| Examining board members: |
Fernando Dini Andreote;
Danice Mazzer Luvizotto;
Valéria Maia de Oliveira
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| Advisor: | Fernando Dini Andreote |
| Abstract | |
Mangroves are considered an unique ecosystem due to its particular combination of environmental conditions, influenced by its location at the interface between land and ocean. The study of this ecosystem becomes urgent since mangroves are disappearing worldwide, and its diversity of microbial groups is still poorly understood. Within this theme, this project aims to describe the possible functionality of bacteria belonging to the phylum Planctomycetes in mangroves. Such organisms are still poorly studied, difficult to cultivate and mainly isolated from marine environments, water treatment and fish farming sites. Within this phylum are found microorganisms belonging to genera described as capable of performing the anaerobic oxidation of ammonium (anammox), a major transformation of nitrogen in environments with low oxygen availability. Here we aimed to describe the possible functionality of bacteria belonging to the phylum Planctomycetes in the mangroves. In order to achieve the target, it was initially performed a comparison of the Planctomycetes genomes with sequences obtained by metagenomics and metatranscriptomics, revealing the presence of sequences with similarity to those affiliated to unknown function and sulfatases. These are hydrolytic enzymes, which catalyze the cleavage of sulfate esters, releasing sulfur on its available form. The analysis of sequences from a metagenomic library (obtained from an oil-contaminated mangrove) allowed the visualization of genomic fragments related to Planctomycetes. It also revealed the presence of genes related with the production of sulfatases, besides the indication of specific genome arrangements, distinct from those describe in organisms allocated in this group, possibly indicating the occurrence of endemicity for Planctomycetes in mangroves. It was reinforced by the cultivation of isolates affiliated to this groups, whose have their affiliation confirmed by the partial sequencing of the 16S rDNA gene. Some isolates clustered composed new clusters within the Planctomycetes phylum, indicating the occurrence of new species. In sum, the characterization of this group by combining in sílico and in vivo analyses, allowed the confirmation of the occurrence of these organisms in mangroves, and generated the first insights about its functioning on this system, where it seems to occur in a differentiated form from those observed in other environments where it has been described. (AU) | |
| FAPESP's process: | 12/03953-6 - Detection and analysis of sequences affiliated to Planctomycetes in metagenomic libraries from mangroves located in the State of Sao Paulo |
| Grantee: | Juliana Eschholz de Araujo Ferreira |
| Support Opportunities: | Scholarships in Brazil - Master |