Investigação metabolômica e genômica de fungos amazônicos por espectrometria de massas e mineração de genoma

Abstract

Fungal natural products and their derivatives have diverse applications, from use as active pharmaceutical ingredients in medicine to the control of agricultural pathogens. To fully explore the metabolome of these microorganisms, mass spectrometry has become an essential tool. Simultaneously, genome mining has recently emerged as a powerful technique to provide information on metabolite production capacity and the corresponding biosynthetic pathways. Given this, the present study aimed to investigate the secondary metabolites of the endophytic fungi Trichoderma agriamazonicum and Arcopilus amazonicus through the combination of liquid chromatography-mass spectrometry and genome mining. For A. amazonicus, oosporein was identified as the main secondary metabolite, and the biosynthetic gene cluster related to its biosynthesis presents one extra monooxygenase gene compared to the cluster related to this molecule in Beauveria bassiana, whose biosynthesis was previously elucidated. Moreover, high-resolution liquid chromatography coupled with mass spectrometry, together with molecular networking analysis, revealed the production of analogous compounds exhibiting different degrees of oxygenation, including phoenicin diquinol, phoenicin quinol, and phoenicin. Based on these findings, a novel putative biphenol oxidation pathway, mediated by the monooxygenase gene AAm15, exclusive to A. amazonicus, is proposed. Genome mining of T. agriamazonicum showed a predominance of genes related to peptide production, which allowed the annotation of a 20-module gene connected to the production of 19-amino-acid-residue peptaibols. Analysis of metabolite profiles indicated that rice and cereal media favor peptaibol production. Using mass spectrometry, peptides from the SF1 and SF5 peptaibol subfamilies were annotated. The known lipopeptaibols trikoningin KB-I, trikoningin KB-II, compounds 10 and 12, and seven novel sequences were identified, where the 19-residue sequences were linked to a hybrid polyketide synthase–non-ribosomal peptide synthetase gene. This research contributes significantly to expanding the knowledge of quinones and peptaibols produced by Amazonian endophytic fungi, including the discovery of novel molecules, thereby reinforcing the value of this biome in the exploration of new natural products.