datacite.subject.fos	Ciências Naturais::Outras Ciências Naturais	pt_PT
dc.contributor.advisor	Reis, Margarida P.
dc.contributor.advisor	Costa, Rodrigo da Silva
dc.contributor.author	Karimi, Elham
dc.date.accessioned	2018-09-17T12:11:49Z
dc.date.available	2018-09-17T12:11:49Z
dc.date.issued	2018-07-27
dc.date.submitted	2018
dc.description.abstract	Sponges are early-branched, filter-feeding metazoans that usually harbor complex microbial communities comprised of diverse “uncultivable” symbiotic bacteria. In this thesis, the functional and taxonomic features of the marine sponge microbiome are determined, using Spongia officinalis as model host organism. Emphasis is given to adaptive and functional traits of the profuse and biotechnologically-relevant alphaproteobacterial symbionts of sponges. A metagenomics-centred approach was employed to reveal microbial taxa and genomic signatures enriched in the Spongia officinalis endosymbiotic consortium, and thus likely to play pivotal roles in holobiont functioning. Further, a comparative genomics study is presented unveiling the common and specific traits of ten Alphaproteobacteria genera isolated from S. officinalis with alternative symbiont cultivation methodology. Finally, a sequence composition-dependent binning approach is employed to assemble, from metagenomic sequences, the genome of an uncultured alphaproteobacterial symbiont of S. officinalis belonging to the family Rhodospirillaceae. High abundance of polyketide and terpene synthase-, eukaryotic-like protein- (ELPs), type IV secretion system-, plasmid- and ABC transporter-encoding genes, among others, characterized the sponge microbial metagenomes. In contrast, motility and chemotaxis genes were abundant in seawater and sediment microbiomes, but nearly absent in the S. officinalis symbiotic consortium. Much higher frequencies of anti-viral CRISPR-Cas and restrictionmodification systems, along with much lower viral abundances, were observed in the spongeassociated metagenomes than in the environment and interpreted as true hallmarks of this symbiotic consortium. In line with outcomes retrieved for the whole symbiotic community, alphaproteobacterial symbionts of marine sponges likely contribute the most to host fitness through nutritional exchange, cell detoxification processes and chemical defense, the latter being theoretically promoted by both polyketide and terpenoid biosynthesis. The several alphaproteobacterial cultures retrieved in this thesis, displaying high natural product biosynthesis capacities, can now be explored in studies aiming at revealing novel biological activities and chemical structures from these symbionts.	pt_PT
dc.description.abstract	As esponjas marinhas (filo Porifera) são consideradas um dos mais simples grupos entre os metazoários em função de sua falta de organização em tecidos e órgãos verdadeiros. Porém, estes animais relativamente simples em termos de plano corporal normalmente abrigam comunidades muito complexas de microorganismos. Em função de seu surgimento basal na história evolutiva do planeta, o conhecimento a respeito deste “holobionte”, isto é, o consórcio de organismos formado pela esponja marinha hospedeira e todos os seus simbiontes microbianos, possui grande relavância ao avanço da nossa compreensão sobre as interações hospedeiro-microorganismos. Nesta tese de doutoramento, tive como objetivo a determinação das características funcionais e taxonómicas do microbioma das esponjas marinhas no contexto de seu ambiente circundante (água e sedimentos marinhos, e suas respecticvas microbiotas), dando ênfase aos traços adaptativos e funcionais de alfaproteobactérias associadas ao organismo modelo Spongia officinalis (“bath sponge”).	pt_PT
dc.identifier.tid	101440499	pt_PT
dc.identifier.uri	http://hdl.handle.net/10400.1/10819
dc.language.iso	eng	pt_PT
dc.subject	Porifera	pt_PT
dc.subject	Metagenómica	pt_PT
dc.subject	Genómica funcional	pt_PT
dc.subject	Alphaproteobacteria	pt_PT
dc.subject	Interacções hospedeiro-microorganismo	pt_PT
dc.title	Metagenomics and functional genomics of bacterial symbionts of Spongia (Porifera, Dictyoceratida) specimens from the Algarvian shore (South Portugal)	pt_PT
dc.type	doctoral thesis
dspace.entity.type	Publication
person.familyName	Karimi
person.givenName	Elham
person.identifier	458972
person.identifier.orcid	0000-0002-2204-0789
rcaap.rights	openAccess	pt_PT
rcaap.type	doctoralThesis	pt_PT
relation.isAuthorOfPublication	b78486f9-a70f-4f4b-aabe-9b2fc1683033
relation.isAuthorOfPublication.latestForDiscovery	b78486f9-a70f-4f4b-aabe-9b2fc1683033
thesis.degree.grantor	Universidade do Algarve. Faculdade de Ciências e Tecnologia
thesis.degree.level	Doutor
thesis.degree.name	Doutoramento em Ciências do Mar, da Terra e do Ambiente	pt_PT

Metagenomics and functional genomics of bacterial symbionts of Spongia (Porifera, Dictyoceratida) specimens from the Algarvian shore (South Portugal)

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