Unveiling the genomes and secondary metabolomes of Streptomyces spp. from freshwater sediments.

Several Streptomyces strains were isolated from freshwater sediments collected in the Laxenburg ponds (Lower Austria). Genome sequencing and bioinformatics analyses revealed biosynthetic gene clusters (BGCs) that may specify production of chemically diverse secondary metabolites. Various culture conditions were employed to induce metabolite production, and subsequent LC-MS analyses facilitated the identification of the produced compounds and their correlation with the corresponding BGCs. These analyses of sediment-derived Streptomyces spp. highlight their extensive biosynthetic potential, revealing a diverse range of bioactive secondary metabolites, including siderophores, antibiotics, and other compounds with potential therapeutic applications. Genomes of two Streptomyces isolates, one of them representing a potentially new species, harbored several uncharacterized BGCs that may specify biosynthesis of novel secondary metabolites. Although targeted overexpression of pathway-specific regulators from these BGCs did not yield additional metabolites, whereas knockout experiments led to metabolic changes, presumably reflecting regulatory or compensatory interactions between multiple biosynthetic pathways. Continued exploration of these strains and their BGCs may lead to the discovery of new bioactive molecules with pharmaceutical and biotechnological applications.