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| Author(s): |
Vitor Bruno Lourenzon
Total Authors: 1
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| Document type: | Master's Dissertation |
| Press: | Ribeirão Preto. |
| Institution: | Universidade de São Paulo (USP). Faculdade de Ciências Farmacêuticas de Ribeirão Preto (PCARP/BC) |
| Defense date: | 2021-07-30 |
| Examining board members: |
Monica Tallarico Pupo;
Camila Manoel Crnkovic;
Luciana Gonzaga de Oliveira
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| Advisor: | Monica Tallarico Pupo |
| Abstract | |
Natural products play an important role in the discovery and development of new drugs. In this context, microorganisms have a remarkable contribution since they are capable of producing several secondary metabolites that are active against different pathogens. The association with microorganisms proved to be an important evolutionary advantage for the most diverse living beings such as plants, insects, and animals. A well elucidate example of this kind of symbiosis is the association of fungus-growing ants of Attina subtribe with actinobacteria, which produce active compounds against specific parasites that threaten the ant colony. In recent studies carried out at the Lab of Microbial Chemistry (LQMo - FCFRP), three chemically related polyketides were identified from the culture of the actinobacteria Streptomyces sp. ICBG311, isolated from a winged male of Cyphomyrmex fungus-growing ant, the novel compound, cyphomycin (15), and two analogues already reported, caniferolide C (16) and GT-35 (17). The compounds presented antifungal potential against entomopathogenic fungus strains and also against human pathogens, in addition to high antiparasitic activity against intracellular amastigote and promastigote forms of Leishmania donovani. In this context, this project contributed to the knowledge about the biosynthetic pathway of cyphomycin and analogs, besides the evaluation of the compounds production in different culture conditions. By analyzing Streptomyces sp. ICBG311\'s genome on AntiSMASH software, the biosynthetic gene cluster (BGC) 1.4 was identified as responsible for the biosynthesis. The BGC is 220 Kb in length containing 83 genes, 25 of them are putatively related to the biosynthesis of compounds 15-17. The polyketide chain is biosynthesized by a type I polyketide synthase (PKS), and modified by cytochrome P450 enzymes that promote punctual oxidations that lead to the differences observed among the three compounds. Sugar biosynthesis starts with glucose-1-phosphate and is performed by nine enzymes. Finally, an intermediate of menaquinone pathway is used as the precursor for the alkylnaphthoquinone biosynthesis, which is completed by the product of three other genes. Aiming to optimize culture conditions, Streptomyces sp. ICBG311 was cultivated in several culture media. However, the production of compounds 15-17 was not reproducible in most of the tested conditions, except for ISP2 agar media. ICBG311 culture in ISP2 agar also presented 53 exclusive ions, when compared with the other media tested, on the metabolomics analyses performed with the LC-ESI-MS/MS data at the Global Natural Product Social Molecular Networking (GNPS) platform. Based on that, ISP2 agar is a promising culture media for future studies regarding the compounds 15-17 production, and the biosynthetic potential presented by the strain ICBG311. Therefore, this study reports the biosynthetic pathway of cyphomycin and analogs and contributes to the optimization of the strain ICBG311 culture conditions for future studies. (AU) | |
| FAPESP's process: | 19/16559-3 - Biosynthetic studies of bioactive macrolactone polyketide from Streptomyces sp. ICBG311 |
| Grantee: | Vitor Bruno Lourenzon |
| Support Opportunities: | Scholarships in Brazil - Master |