Physicochemical Properties and Antimicrobial Activity of the Streptomyces sp. B19 Antibiotic

• Datum: 2025
• Hauptverfasser: Matselyukh, B.P., Yarmolyuk, S.M., Bieda, O.A., Мацелюх, Б.П., Ярмолюк, С.М., Бєда, О.А.
• Format: Artikel
• Sprache: Englisch
• Veröffentlicht: PH "Akademperiodyka" of the NAS of Ukraine 2025
• Online Zugang: https://ojs.microbiolj.org.ua/index.php/mj/article/view/353
• Назва журналу: Microbiological Journal

Streptomycetes represent an important part of soil microbiota and play an important role in the decay of vegetation, the natural defenses of plants and nutrient cycling. These microorganisms synthesize various compounds, including antibiotics that have been successfully used in medicine, veterinary science and agriculture. Furthermore, they have the potential to help overcome the growing problem of antibiotic resistance in microorganisms. The aim of the present work was to search for soil streptomycetes and to study their ability to synthesize antibiotics against pathogenic microorganisms, as well as the physicochemical properties of the antibiotics. Methods. Suspensions of soil were sowed on Čapek medium with nystatin in Petri dishes in order to identify individual colonies of streptomycetes and reseed them on soybean-corn medium. The most active antibiotic producers among the isolated streptomycetes were identified by their diffusion into agar medium S seeded with appropriate bacterial test cultures The antibiotic was extracted from the streptomycete culture in two ways: with water and using a chloroform-acetone mixture (2:1), followed by evaporation of the mixture in a rotary evaporator at 80oC and dissolution of the dry extract of the antibiotic in 40 % ethanol. The pure antibiotic was isolated by thin-layer chromatography (TLC) of both organic and aqueous extracts, and its absorption spectrum was obtained by spectrophotometry. The molecular weight of the purified antibiotic was determined using a high-performance liquid chromatography with mass spectrometry detection (HPLC-MS) system Agilent 1260 Infinity II. Results. 33 strains of soil streptomycetes were isolated, of which 17 strains (51.5%) showed antibacterial activity against 4 pathogenic bacteria – Staphylococcus aureus and three phytopathogens. Only 4 strains of streptomycetes B8, B19, B2, and B28 showed high antibiotic activity, the diameters of the zones of absentee of bacterial growth were above 20 mm. From the most active culture Streptomyces sp. B19, two antibiotics were extracted and purified with TLC. The absorption spectrum of the extracted antibiotics between 200 and 500 nm was determined spectrophotometrically. We found that an antibiotic with mass a spectrum mass of 1077 remains on the starting line during organic phase chromatography of positively charged ions of an alkaline extract of the streptomycete culture. For the aqueous phase two compound with mass spectra of 585.5/773.5 and 1194/1301 are isolated. Conclusions. The presence of peptide bonds in the structure and the absorption spectrum of the antibiotic with a molecular mass of 1077 indicate its classification among the new glycopeptide antibiotics.