Building Up a Library of Gram-Negative Bacteria Strains Towards the Investigation of Their Secondary Metabolism

• Grant number: 24/18172-7
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: April 01, 2025
• End date: March 31, 2028
• Field of knowledge: Health Sciences - Pharmacy - Pharmacognosy
• Principal Investigator: Roberto Gomes de Souza Berlinck
• Grantee: Evelyn Assis de Andrade
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil
• Associated research grant: 19/17721-9 - The role of Chemistry in holobiont adaptation, AP.TEM

Abstract

The investigation of the secondary metabolism of microorganisms is one of the main ways for the discovery of bioactive metabolites with potential for use by the pharmaceutical industry. However, to date, the discovery of bioactive metabolites for development as potentially pharmacologically active hits of microbial origin has mainly used Gram-positive bacteria and filamentous fungi as biological matrices. On the other hand, the secondary metabolism of Gram-negative bacteria has been much less investigated. Considering the expertise already acquired by Professor Berlinck's group in discovering metabolites from Gram-positive bacteria and fungal strains, as well as the enormous potential for discovering: a) new Gram-negative bacteria strains not yet described in the literature; b) new bioactive secondary metabolites produced by these lineages; and c) the importance of better understanding the secondary metabolism of Gram-negative bacteria, this project aims to be the first investigation of non-photosynthetic Gram-negative bacteria in Brazil. The goal is to establish a bank of these bacteria lineages and obtain information on their cultivation, taxonomy, and production of bioactive secondary metabolites. Therefore, the objectives of this project can be summarized as: a) collecting samples of soil, roots, and non-filtering marine invertebrates in the Alcatrazes Archipelago (SP) for isolating Gram-negative bacteria. Samples of different types of propolis (green, brown, and red) that have already been collected and processed will also be used as matrices for isolating Gram-negative bacteria; b) selecting appropriate culture media for the isolation and growth of Gram-negative bacteria; c) performing taxonomic analyses of the isolated lineages; d) cultivating lineages in liquid medium to obtain growth media to be extracted and pre-fractionated for sending to bioassays and undergoing dereplication; e) submitting the pre-fractionation fractions to bioassays for antiplasmodial activity against Plasmodium falciparum, leishmanicidal activity against Leishmania spp., activity against T. cruzi, antibacterial activity against pathogenic bacterial strains susceptible and resistant to antibiotics, and cytotoxic activity against different tumor cell lines; f) conducting multifactorial analysis using dereplication and metabolomics tools in combination with biological activity data to prioritize the study of Gram-negative bacterial lineages for the subsequent investigation and discovery of novel bioactive secondary metabolites. We consider this project to be of significant importance, not only for its novelty at the national level but also for initiating the investigation of the secondary metabolism of Gram-negative bacteria, significantly contributing to expanding and deepening knowledge about Brazilian microbial biodiversity.