Diversidade biossintética de metabólitos secundários de fungos dos gêneros Pestalotiopsis, Pseudopestalotiopsis e Neopestalotiopsis

Abstract

Fungi from the genera Pestalotiopsis, Neopestalotiopsis, and Pseudopestalotiopsis are recognized for their ability to produce structurally complex secondary metabolites with antiviral, antimicrobial, and antitumoral activities, making them of significant agricultural and biotechnological interest. This study aimed to explore, through genome mining, the diversity of biosynthetic gene clusters (BGCs) and gene cluster families (GCFs) in 23 genomes from these three genera (9 Pestalotiopsis, 10 Neopestalotiopsis, and 4 Pseudopestalotiopsis), including 17 strains from public databases (NCBI and JGI) and 6 pathogenic Amazonian strains from the Embrapa Western Amazon collection. BGC identification and annotation were performed using antiSMASH version 8.0, followed by sequence similarity network analysis and clustering into families using BiG-SCAPE, enabling molecular network construction and synteny analysis. A total of 2,113 BGCs were identified and classified into seven major categories: NRPS (795 BGCs), PKSI (607 BGCs), terpenes (282 BGCs), others (596 BGCs), PKSother (162 BGCs), PKS-NRP hybrids (138 BGCs), and RiPPs (36 BGCs), highlighting the predominance of nonribosomal peptide and type I polyketide biosynthetic pathways. Genus-level analysis revealed that Neopestalotiopsis exhibited the highest number of BGCs (989), with a balanced composition of PKSI (27.40%), NRPS (25.48%), and terpenes (12.74%), suggesting greater metabolic versatility. Pestalotiopsis showed 666 BGCs, mainly NRPS (28.98%) and PKSI (28.68%), while Pseudopestalotiopsis presented 458 BGCs, with a predominance of the “others” category (29.26%). Clustering analysis identified 632 GCFs, including 165 NRPS, 141 PKSI, 168 others, 63 terpenes, 47 PKSother, 36 PKS-NRP hybrids, and 12 RiPPs. Most GCFs were genus-specific (unique) or singletons, with only 9 core GCFs shared among the three genera, indicating high metabolic specialization and low conservation of biosynthetic pathways. Comparison with the MIBiG database revealed that only 4 GCFs (0.63%) matched experimentally characterized clusters, encompassing 19 BGCs (0.9% of the total), including type I polyketides, pestheic acid, indole derivatives, chloropestolides, and flavunoidin. These results indicate that more than 99% of GCFs correspond to orphan clusters with unexplored biosynthetic potential. The integrated computational approach employed in this study highlights the relevance of bioinformatics for large-scale secondary metabolite prospecting and for understanding the functional evolution of BGCs in filamentous fungi, reinforcing the potential of pestaloid fungi, particularly Amazonian strains from a megadiverse biome, as promising sources of novel bioactive compounds for biotechnological and pharmaceutical applications.