Molecular phylogeny and biosynthetic potential of Streptomyces distallicus IMV Ac-5025

Streptomyces spp. are the main producers of antimicrobial and other bioactive compounds, which determined the interest of researchers in representatives of this genus. A hypothesis was proposed suggesting that the strain possessed a broad metabolite spectrum and a potential ability to synthesize diverse antibiotics, including those with larvicidal, anthelmintic, and antimicrobial properties. It exhibited antagonistic activity against phytopathogenic fungi and was considered promising for biotechnological applications in agriculture. The aim of this study was to perform whole-genome sequencing in order to determine the evolutionary relationships and biosynthetic potential of Streptomyces distallicus IMV Ac-5025, with particular emphasis on its capacity to produce antimicrobial compounds. Whole-genome sequencing was performed using an Illumina NovaSeq 2 & times; 150 bp and assembled with the SPAdes v4.0.0 method and was annotated. The search for similar genomes and genomic phylogeny was conducted at the Bacterial and Viral Bioinformatics Resource Centre. Biochemical tests using minimal nutrient media were performed to determine phenotypic characteristics of the strain. Crude extracts were analyzed for the presence of antibiotics using Q Exactive liquid chromatography-tandem mass spectrometry and high-performance liquid chromatography. The antibiotics susceptibility was assessed using a modified disk diffusion method, antifungal activity was determined using a dual-block confrontation assay. The genome assembly yielded 8 contigs, with a total length of 7,564,690 bp. Analysis of the biosynthetic gene clusters revealed a broad biosynthetic potential of the strain, notably including clusters associated with antibiotic production. The strain was found to synthesize aureothin and distamycin, which, in addition to its antifungal activity, broaden the spectrum of its bioactivity. Cultivation conditions affected aureothin production, with the highest yield (52.321 +/- 0.957 ug/uL) obtained by ethanolic extraction from biomass when the producer grown in GYM nutrient medium. The results highlight the biotechnological potential of secondary metabolites from S. distallicus IMV Ac-5025, which combine strong antifungal activity with promising nematicidal properties, thereby supporting their relevance for integrated plant protection strategies.