The skin of reptiles is a unique ecological niche and a promising source of microorganisms with antimicrobial activity that contribute to the host’s defense system, acting as a natural bacterial filter. A distinctive feature of strain Lzd4kr isolated previously from the skin surface of a sand lizard (Lacerta agilis) is its ability to produce a metabolite capable of forming extracellular blue-colored crystals. Whole-genome sequencing and phylogenetic analysis revealed that strain Lzd4kr was a Streptomyces chartreusis strain. Bioinformatic analysis of the genome of the new isolate Streptomyces sp. Lzd4kr identified gene clusters responsible for the biosynthesis of such antimicrobial compounds as actinorhodin, puromycin, and analogs of peptide antibiotics, including Zoocin A and Avermipeptin. The study demonstrates that both the composition of the growth medium and the method of sample preparation significantly affected the antimicrobial activity of exometabolites produced by the new isolate. The extract obtained from Streptomyces sp. Lzd4kr cultivated on the CP-1 medium supplemented with glycerol exhibited the highest antimicrobial effect, inhibiting the growth of 18 out of 21 tested microbial strains.
Носков et al. (Mon,) studied this question.