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Bacillus megaterium is a gram - positive rod-shaped endospore-forming bacteria. They are used as an effective soil modifier, having the ability to disperse phosphorus. In turn, phosphorus plays an important role in several physiological and biochemical processes of plants, such as photosynthesis, the conversion of sugar to starch, and the transfer of genetic traits. Based on the current state of research in the development of biofertilizers, it can be argued that the biocomposition of Bacillus megaterium bacteria will lead to an increase in the availability of a number of macronutrients for plants – the main elements of nutrition. This article presents the results of screening studies of previously created collection of bacterial strains of Bacillus megaterium from the Museum of the Department of microbiology, virology, epizootology and VSE of Ulyanovsk SAU. The developed scheme of isolation and identification of Bacillus megaterium bacteria is given. The species identity of 6 strains of B. megaterium was confirmed. The results of the research are compared with the characteristic phenotypic properties of the studied species described in "Bergey's Manual of Systematic Bacteriology" (2015). 210 soil samples were taken to isolate new strains of microorganisms. Initial identification allowed us to isolate 58 strains of bacteria of the genus Bacillus, 16 were assigned to Bacillus megaterium. The percentage of contamination of soil samples of this type of bacteria was 7.6 %. As the result of research, the collection of bacterial strains of studied microorganisms was expanded and their taxonomic affiliation was determined. The resulting collection will be the object of research at the following stages of work on the development of biocomposition based on bacteria to increase the coefficient of absorption of mineral components of fertilizers.

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Phytopathogenic bacteria Pseudomonas syringae cause diseases of many cultivated plants, causing tumor neoformation, rot, chlorosis, necrosis, etc . The advanced biological mean to control bacteriosis in crop science is bacteriophages. In this work full biological characteristic of 8 bacteriophages is shown, active according to Pseudomonas syringae. The studied phages formed similar negative colonies- clear, rounded, in diameter of 5-9 mm. Lytic actifity of phages Pseudomonas syringae by Appelman from 10-4 to 10-8; by Gratia from 1,0±0,1×106 to 2,0±0,1×109 (BFU/ml). Bacteriophages Ps.s-7 UlGAU, Ps.s-13 UlGAU and Ps.s-27 UlGAU did not change lytic activity when storing in fridge during 12 months. Lytic activity of phages Ps.s-1 UlGAU, Ps.s-8, Ps.s-15 UlGAU, Ps.s-30 UlGAU, Ps.s-77 UlGAU in the same conditions fell within 1-2 orders. Spectrum of lytic activity of phages varied from 21,4% (Ps.s-13 UlGAU) to 85,7% (Ps.s-7 UlGAU, Ps.s-27 UlGAU). The study of phage specificity on 15 species og heterologous cultures showed that phages are specific for Pseudomonas syringae. Phages are moderately stable to heating and lose activity during 30 –minute temperature effect above 62°С. The optimal way to relieve phage lysate from living cells of Pseudomonas syringae was thrichloromethane at a ratio of 10:1and temporal exposition 45 minutes. On the basis of obtained data we determined capacity of each bacteriophage for the use as biocontrol agent. For further research for the study of molecular genetic characteristics we selected advanced strains of phages Pseudomonas syringae - Ps.s-7 UlGAU и Ps.s-27 UlGAU.