MORPHOLOGICAL CHARACTERISTICS AND CYTOTOXIC ACTIVITY OF THE BLACK SEA STRAIN STREPTOMYCES SP. LIM 10

Aim. The aim of the work was to study the morphological characteristics and cytotoxic activity of the strain of actinobacteria Streptomyces sp. Lim 10 isolated from natural fouling of shell rock in the Odesa Bay of the Black Sea. Materials and methods. The object of the study was a strain of marine actinobacteria Streptomyces sp. Lim 10. The morphology and growth patterns were studied on the media of Gauze 2, Czapek, Eshbi, TSB and on the media of ISP (ISP-1–ISP-7). SG medium was used to accumulate secondary metabolites of actinobacteria. Extraction of exometabolites from the culture liquid was carried out with ethyl acetate followed by dissolution in dimethyl sulfoxide (DMSO). The cytotoxic activity of exometabolites of actinobacteria strain Streptomyces sp. Lim 10 was studied on the model of cultures cells human - rhabdomyosarcoma (RD,) and of the laryngeal adenocarcinoma (Hep-2). The cytotoxic effect of exometabolites of the actinobacteria strain Streptomyces sp. Lim 10 was determined after 24 hours of incubation by microscopy. The degree of destruction of the monolayer was assessed by the number of viable cells in terms of optical density, which was measured using a spectrophotometer at a wavelength of 630 nm. The exometabolites of actinobacteria strain Streptomyces sp. Lim 10 were identified using LC-ESIMS. Results. Study of the morphological properties of the Black Sea strain of actinobacteria Lim 10 showed that it is characterized by pleomorphism. А high cytotoxic activity of exometabolites of the marine strain of actinobacteria Streptomyces sp. Lim 10 was established. The level of cytotoxic effect of metabolites of the strain of actinobacteria Streptomyces sp. Lim 10 on Hep-2 cell culture depended on their concentration. RD cell culture was more sensitive to the cytotoxic effect of exometabolites of Streptomyces sp. Lim 10 – at all tested concentrations of exometabolites (from 2.5 to 500.0 μg/ml), the number of viable cells in the RD monolayer decreased to 51.3 ± 3.0 – 63.7 ± 5.4%, compared to the control. This can be at least partially explained by action of apoptosis-inducing agent staurosporine, which is produced by strain Streptomyces sp. Lim 10 along with itsstructural homologs. Conclusion. Strain Streptomyces sp. Lim 10 is a promising producer of antitumor compounds and can be recommended for further more in-depth studies.