Genomic, biological, and chemical studies of Streptomyces sp. LaBMicrA B280 isolated from the rhizosphere of Inga edulis Martius in the Amazon

In this study, we investigated the taxonomic identity and biotechnological potential of the actinobacterium Streptomyces sp. LaBMicrA B280, isolated from the rhizosphere of Inga edulis (Mart.). Our approach combined a phylogenomic approach, annotation of metabolic subsystems and biosynthetic gene clusters (BGCs), biological assays to assess antifungal, antimalarial, cytotoxic, and larvicidal activities, classical molecular networking analysis, and characterization of the major compound in the most active fraction (FR3). The digital DNA-DNA hybridization values, using the d2 (GGDC) and d4 (TYGS) formulas, average nucleotide identity, and average amino acid identity (< 70% and ≤ 95-96%, respectively) revealed LaBMicrA B280 as a novel species within the Streptomyces genus. Our genomic analysis revealed 39 BGCs, including the cluster responsible for pentamycin biosynthesis, 314 metabolic subsystems, and 24 gene categories. In the molecular networking analysis, pentamycin was the only compound identified. Biological assays with fraction FR3 at a concentration of 50 µg/mL showed 96.59% ± 0.03 and 72.39% ± 0.18 inhibition against Plasmodium falciparum strains W2 and 3D7, respectively, as well as 91.45% ± 0.55 cytotoxicity against the HEp-2 cancer cell line. Larvicidal activity assays demonstrated 100% efficacy against Aedes aegypti (FO) at 250 µg/mL after 48 h. Pentamycin, a known antifungal compound, was successfully isolated from the highly active FR3 fraction. These findings highlight that LaBMicrA B280 exhibits a broad biotechnological potential and represents a promising source of important secondary metabolites for future application.