GENOMIC ANALYSIS OF THE STREPTOMYCES SP. LV42-5 ISOLATED FROM INDUSTRIAL MINE DUMPS IN SHEPTYTSKYI

Abstract

Actinomycetes, particularly within the genus Streptomyces, remain the most prolific bacterial source of secondary metabolites for medical and biotechnological applications. However, contemporary drug discovery is increasingly challenged by the high rate of rediscovering known molecules and the difficulty of activating "silent" biosynthetic gene clusters (BGCs) under standard laboratory conditions. To address this, bioprospecting in extreme environments, such as heavy metal-contaminated mine dumps, has emerged as a strategic approach to uncover strains with unique metabolic adaptations and chemically diverse natural products. This study reports the whole-genome sequencing, assembly, and comprehensive bioinformatic analysis of Streptomyces sp. Lv42-5, an extremotolerant strain isolated from the rhizosphere of birch trees (Betula pendula) growing on an industrial mine dump in Sheptytskyi, Ukraine. Genomic sequencing utilizing the Illumina platform followed by de novo assembly yielded a high-quality draft genome of 9.84 Mbp with a G+C content of 71%. Phylogenomic analysis using the GTDB and ANI calculation revealed that strain Lv42-5 shares only 93.36% ANI with its closest relative, Streptomyces diastatochromogenes. This value falls well below the 95-96% species delineation threshold, confirming Lv42-5 as a taxonomically novel species. Functional annotation via the RAST server indicated a genome heavily dedicated to metabolic processes, particularly amino acid and carbohydrate metabolism, while lacking genes for motility and photosynthesis. Crucially, the genome encodes a robust genetic arsenal for heavy metal resistance, including specific mechanisms for tolerating copper, cobalt, zinc, and cadmium, reflecting the strains successful adaptation to its metalliferous habitat. Genome mining using antiSMASH 8.1 uncovered a rich biosynthetic landscape comprising 43 putative gene clusters. These findings establish Streptomyces sp. Lv42-5 as a novel, stress-adapted species with significant dual potential for bioremediation of heavy metal pollutants and the discovery of novel therapeutic agents.