Shtenikov M. Aerobic spore-forming bacteria of deep-water sediments of the Black Sea

The dissertation is devoted to the study of biological diversity and biological characteristics of aerobic sporeforming bacteria of deep-water bottom sediments of the Black Sea and the determination of their potential regarding the production of antimicrobial compounds. As a result of research in deep-water sediments of the Black Sea with extreme anaerobic conditions, aerobic sporeforming bacteria were discovered, their biological diversity was characterized, as well as biological properties, genome structure, metabolomes and spectra of antimicrobial compounds of antagonistically active strains. For the first time isolates of spore-forming bacteria were isolated from the bottom sediments of the Black Sea, which by the fatty acid spectra analysis were assigned to 14 species and were characterized by antagonistic activity to the opportunistic pathogens of humans and animals. According to the results of screening of antagonistically active bacteria, 3 strains were selected and were identified by the methods of molecular phylogenetics and comparative genomics as Bacillus velezensis ONU 553, Bacillus pumilus ONU 554 and Bacillus subtilis ONU 559, as such with the highest activity. Among the secondary metabolites of the studied strains, variants of the most studied class of non-ribosomal peptides - surfactins (anteiso-C16-surfactin, surfactin B2 1-Me ester), gageostatins, fengycins, and amicoumacins, as well as a secreted pentapeptide with the ability to inhibit proteases GPFPI. Data on other compounds identified for bacilli for the first time require further verification. The practical significance of the obtained results consists of the replenishment of the Collection of the sea and useful microorganisms of Odesa I. I. Mechnikov National University with new strains of marine bacteria, as well as data on studies of genomes and exometabolomes of antagonistically active strains could be a scientific basis for the development of their base producers of new compounds for industry and probiotic preparations.