Microbiota associada aos cnid??rios Millepora alcicornis e Phyllogorgia dilatata: diversidade microbiana e prospec????o de mol??culas ativas

Autor: Macedo, Maria Wanna Figueiredo Sena
Přispěvatelé: Cunha, Nicolau Brito da
Jazyk: portugalština
Rok vydání: 2020
Předmět:
Zdroj: Biblioteca Digital de Teses e Dissertações da UCB
Universidade Católica de Brasília (UCB)
instacron:UCB
Popis: Submitted by Sara Ribeiro (sara.ribeiro@ucb.br) on 2020-05-04T22:45:45Z No. of bitstreams: 1 MariaWannaFigueiredoSenaMacedoDissertacao2020.pdf: 3024711 bytes, checksum: b6608fa8da7eb91ba679e2d1b25b5940 (MD5) Approved for entry into archive by Sara Ribeiro (sara.ribeiro@ucb.br) on 2020-05-04T22:46:17Z (GMT) No. of bitstreams: 1 MariaWannaFigueiredoSenaMacedoDissertacao2020.pdf: 3024711 bytes, checksum: b6608fa8da7eb91ba679e2d1b25b5940 (MD5) Made available in DSpace on 2020-05-04T22:46:18Z (GMT). No. of bitstreams: 1 MariaWannaFigueiredoSenaMacedoDissertacao2020.pdf: 3024711 bytes, checksum: b6608fa8da7eb91ba679e2d1b25b5940 (MD5) Previous issue date: 2020-02-14 Coral reefs are marine ecosystems that are home to a great biodiversity, forming complex food webs and serving as shelter for various organisms. Due to their high degree of diversity, these environments have a biotechnological potential that is still unknown and little explored, having been studied the produce bioactive molecules organisms, such as polyketides (PKs) and non-ribosomal peptides (NRPs) that can be used in the pharmaceutical, nautical or food industries. Brazilian coral reefs have a unique composition, as they are formed by a large number of endemic species and have a little-found structure, that are named chapeir??es. These reefs extend throughout the northeast coast and commonly can be observed the species of stony corals, black corals, fire corals and octocorals. Corals and other marine invertebrate animals have been studied as to their potential in the production of compounds with biological activity, showing a positive result in the studies already carried out, including, evidencing the role of the microorganisms associated with them in the production of these compounds. Due to the increase in global warming and the damage caused to marine environments through anthropic activities, it??s clear the rapid decline in the population number of coral-forming cnidarians reefs. Recently, 90% of the mortality of the species Millepora alcicornis has been observed in the Costa do Descobrimento (BA), as it promotes the search for new ideas for the preservation of reef environments and the study of these ecosystems in relation to their chemical potential. In this study, the corals M. alcicornis and Phyllogorgia dilatata had the cultivable bacterial community associated with them, isolated and identified, using molecular techniques, where it was possible to observe a large number of organisms from the phyla Proeobacteria and Firmicutes, with the majority of the isolates identified as belonging to the Vibrio genus. The bacterial isolates were tested, when the presence of antimicrobial activity, against ATCC strains of Escherichia coli and Staphylococcus aureus, and a positive result was verified for 29 isolates, all belonging to the Vibrio genus. It was also carried out the prospecting of genes encoding enzymes responsible for the synthesis of PKs and NRPs in bacterial isolates, with 27 isolates found that have one of the coding genes. This search also analyzed the relationship between the presence and absence of the gene with a positive result in terms of antimicrobial activity, noting that most isolates that showed amplification of the target gene did not demonstrate antimicrobial activity, a fact that may be related to the presence of silent genes in these samples. Os recifes de coral s??o ecossistemas marinhos que abrigam uma grande biodiversidade, formando teias alimentares complexas e servindo de abrigo para diversos organismos. Por apresentar um alto grau de diversidade, esses ambientes guardam um potencial biotecnol??gico ainda desconhecido e pouco explorado, tendo sido estudados organismos produtores de mol??culas bioativas, como policet??deos (PKs) e pept??deos n??o-ribossomais (NRPs) que podem ser utilizadas nas ind??strias farmac??utica, n??utica ou aliment??cia. Os recifes de coral brasileiros possuem uma composi????o ??nica, por ser formado por um grande n??mero de esp??cies end??micas e ter uma estrutura pouco encontrada, os chamados chapeir??es. Esses recifes se estendem por todo litoral nordeste e comumente podem ser observadas as esp??cies corais-p??treos, corais negros, corais-de-fogo e octocorais. Os corais e outros animais invertebrados marinhos vem sendo estudados quanto ao seu potencial na produ????o de compostos com atividade biol??gica, mostrando um resultado positivo nos estudos j?? realizados, inclusive, evidenciando o papel dos microrganismos a eles associados na produ????o desses compostos. Com o aumento do aquecimento global e dos danos causados aos ambientes marinhos por meio de atividades antr??picas, ?? evidente o r??pido decl??nio no n??mero populacional dos cnid??rios formadores de recifes de coral. Recentemente, foi observado 90% de mortalidade da esp??cie Millepora alcicornis na Costa do Descobrimento (BA), dado que impulsiona a buscar novas estrat??gias para a preserva????o dos ambientes recifais e ao estudo desses ecossistemas com rela????o ao seu potencial biotecnol??gico. Neste trabalho os corais M. alcicornis e Phyllogorgia dilatata tiveram a comunidade bacteriana cultiv??vel, a eles associados, isolada e identificada, por meio de t??cnicas moleculares, onde foi poss??vel observar um grande n??mero de organismos dos filos Proteobacteria e Firmicutes, sendo a maioria dos isolados, 73 dos 135 isolados obtidos, identificados como pertencentes ao g??nero Vibrio. Os isolados bacterianos foram testados, quanto ?? presen??a de atividade antimicrobiana, contra cepas ATCC de Escherichia coli e Staphylococcus aureus, sendo verificado um resultado positivo para 29 isolados, todos pertencentes ao g??nero Vibrio. Realizou-se tamb??m a prospec????o de genes codificadores de enzimas respons??veis pela s??ntese de PKs e NRPSs nos isolados bacterianos, sendo encontrados 27 isolados que possuem um dos genes codificadores. Esse estudo analisou tamb??m a rela????o entre a presen??a ou aus??ncia do gene com um resultado positivo quanto a atividade antimicrobiana, sendo notado que grande parte dos isolados que apresentaram amplifica????o do gene alvo n??o demonstrou atividade antimicrobiana, fato que pode estar relacionado a presen??a de genes silenciosos nessas amostras.
Databáze: OpenAIRE
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