Diversidade e bioprospecção de fungos associados a liquens presentes em ecossistemas extremos

• Ano de defesa: 2016
• Autor(a) principal: Iara Furtado Santiago
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Microbiologia
• Link de acesso: http://hdl.handle.net/1843/BUBD-AA9GXT

Micro-organisms are extremophiles those able to survive in environments where environmental parameters (physical and/or chemical ) differ from normality. These micro-organisms do not only tolerate too extreme conditions specific to require the same to survive and it is believed that this plasticity extreme condition affecting the primary and secondary metabolic pathways. This study aims to characterize thediversity of fungi associated with lichenized fungi present in extreme ecosystems, evaluate their potential to produce bioactive metabolites and seek eukaryotic models for studies of astrobiology. Lichenized fungi samples were collected on three islands on the Antarctic Peninsula (Elephant, King George and Deception), in Fields Altitude in Brazil and in the Atacama Desert, Chile. From these samples were obtained from a total of 919 fungal isolates (812 filamentous fungi and 107 yeasts). The fungi present in samples obtained from Antarctic islands belong to the genera Antarctomyces, Bensingtonia, Candida, Capnobotryella, Capnodiales, Catenulostroma, Cladosporium,Cryptococcus, Fusarium, Holtermanniella, Leptosphaeriaceae, Leucosporidiella, Mrakia, Mortierella, Penicillium, Pseudogymnoascus, Purpereocillium, Rhodotorula, Thelebolus, Tremella and Yarrowia. The isolates from lichenized fungi in Altitude Fields were identified as belonging to the genera Acremonium, Alternaria, Arthrinium, Aspergillus, Bipolaris,Cladosporium, Cosmospora, Curvularia, Didymellaceae, Eurotium, Flavomyces, Fusarium, Lasiodiplodia, Microdiplodia, Montagnula, Neopestalotiopsis, Ochrocladosporium, Paraconiothyrium, Paraphaeosphaeria, Penicillium, Pestalotiopsis, Phaeobotryosphaeria, Phoma and Trichoderma. The samples of the Atacama Desert the predominant genera were Acremonium, Alternaria, Aspergillus,Botrytis, Cladosporium, Colletotrichum, Coniochaeta, Coprinopsis, Cryptococcus, Fusarium, Gelasinospora, Lecythophora, Meyerozyma, Neopestalotiopsis, Penicillium, Preussia, Psathyrella, Rhodosporidium, Torulaspora e Ulocladium. Fungi were cultivated and 919 ethanol extracts were prepared for bioprospecting studies, which were evaluated in antimicrobial activity assays. After screening, 37 extracts showedactivity against at least one target micro-organisms (six extracts of fungi of Antarctica, nine Field Elevation and 22 of the Atacama Desert) Thirteen extracts showed activity were chemically characterized through its Nuclear Magnetic Resonance H1 (RMN),