Banca de QUALIFICAÇÃO: CLARA DETULIO MARTINS CAVALCANTE

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : CLARA DETULIO MARTINS CAVALCANTE
DATE: 02/05/2025
TIME: 09:00
LOCAL: videoconferência
TITLE:

Genomic and metabolomic prospection of antimicrobial molecules from Bacillus spp.

KEY WORDS:

Bacillus spp.; Antimicrobial Peptides; Genome Mining; Metabolomics; Mass Spectrometry; NMR; Antimicrobial Resistance

PAGES: 111
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Orgânica
SPECIALTY: Química dos Produtos Naturais
SUMMARY:

Antimicrobial resistance represents one of the main threats to global public health and has stimulated the search for new antimicrobial compounds. Natural products have emerged as a promising source of bioactive molecules, of which the secondary metabolites produced by microorganisms represent a valuable strategy for the development of new antimicrobials. Among them, species of the Bacillus genus have been widely investigated for their ability to produce antimicrobial peptides and other compounds of pharmacological interest. In this study, eighteen Bacillus spp. strains isolated from environments exposed to petroleum derivatives were analyzed in order to investigate their biosynthetic potential using integrated genomic and metabolomic mining approaches. Genome analysis using the AntiSMASH tool resulted in the annotation of several biosynthetic gene clusters (BGCs), with emphasis on the structural classes of non-ribosomal peptides, terpenes and polyketides. The strain Bacillus paralicheniformis BD165 was selected based on the diversity and relevance of the BGCs annotated and cultivated in optimized medium (MRS broth supplemented with 10% maltose) for 48 hours. The extracts were obtained by liquid-liquid extraction with ethyl acetate and butanol, which were subjected to chromatographic fractionation and characterized by Mass Spectrometry and Nuclear Magnetic Resonance. UPLC-QTOF-MS/MS analysis revealed the presence of cyclic peptides compatible with bioactive compounds previously described in the literature, including cyclo(Pro-Val), cyclo(Pro-Leu), cyclo(Leu-Leu), cyclo(Leu)4 and thermoactinoamide J. Fractions selected by the 1H NMR chemical profile were subjected to one- and two-dimensional NMR experiments, allowing partial structural characterization of the majority compounds, presenting results compatible with the compounds annotated in mass spectrometry and genome mining. The set of data obtained reinforces the biosynthetic potential of Bacillus spp. and contributes to the lack of spectral information that is poorly represented in public databases. The results lay solid foundations for further chemical prospecting of the species, including the characterization of other fractions, dereplication analyses, evaluation of antimicrobial activity in silico and in vitro biological assays with isolated compounds.

COMMITTEE MEMBERS:
Externa à Instituição - CLÁUDIA QUINTINO DA ROCHA - UFMA
Externa à Instituição - JÚLIA FIRME FREITAS - UFRN
Interno - 2276354 - LEANDRO DE SANTIS FERREIRA
Presidente - 1569526 - RENATA MENDONÇA ARAUJO