Bacterial preparations contribute to the digestion of mineral nutrition, have antifungicidal activity, increase the grain productivity and biomass of cultivated crops. We studied the influence of microbiological preparations developed on the basis of microorganisms Bacillus subtilis and Lactobacillus buchneri on the growth processes, photosynthetic parameters and grain productivity of barley (Hordeum vulgare L.) of Sonet variety. The experiments were performed in 2019 in the North-West of the Russian Federation. The biological preparations were introduced by soaking seeds and treatment of the plants in the phase of third leaf with solutions of the preparations in the concentration of 1 mL/L. The laboratory surveys revealed the positive effect of the biological preparations on germination rate and energy of germination of seeds. Field trials were conducted on micro plots in six replications. During field experiments, we determined that introduction of biological preparations led to significant increase in the leaf area in the experimental plants (to 64.5%), increase in average daily growth gains (to 82.9%) and accumulation of biomass (to 73.1%). Somewhat higher efficiency was exerted by the biological preparation developed on the basis of a strain of L. buchneri. Perhaps, such effect takes place due to higher activity of pigment units of phytohormones of the auxin group. In our opinion, biological preparations accelerate the completion of the ontogenesis phases, thus the plants more rapidly achieve their genetically programmed sizes and transform to the stage of ear-formation. The studied biological preparations increased the coefficient of agricultural use of plants, and grain productivity of barley by up to 15.8%, and nutritional value remained. Microbial preparations on the basis of B. subtilis and L. buchneri exhibited efficiency, and their trials shall be continued on other crops on industrial scales.

The article explores the impact of microbial biologics on the yield of one-year ryegrass and the quality characteristics of feed obtained during the silage of green crop mass. The introduction of preparations, made on the basis of live strains of microorganisms – Bacillus subtilis (“Naturost”), Lactobacillus buchneri (“Naturost-Aktiv”), and Bacillus megaterium (“Naturost-M”), was carried out by soaking the seeds before sowing and processing vegetative organs of plants. Small-scale field studies were conducted in the Vologda Oblast in 2019–2020, and silage experiments were held in a laboratory. Under the influence of biologics, the productivity of ryegrass green mass has increased up to 41.2 %. Moreover, biologics had an impact on the preservation of nutrients in the produced silage, the yield of feed units, and exchange energy in ryegrass silage mass from the seeding area of the experimental variants was higher, compared to the control, by 36.2–52.8% and 31.3–42.8%, respectively. A high yield of green crop mass was obtained in experiments using the “Naturost-Aktiv” and “Naturost” biologics. In terms of physical and chemical parameters and nutritional value, the best feed was obtained from ryegrass biomass in the variant with a preparation based on Bacillus subtilis (“Naturost”) bacteria.

The development of a method suitable for identification of group A streptococci by microprecipitation in gels is described. The method is based on preparation of specific sera containing high antibody levels against the antigenic determinant characteristic of group A streptococcal polysaccharide. In a comparative study with a counterimmunoelectrophoresis method, the proposed test proved to be specific, easily read, and less complicated. Results were obtained in 2 h. Determination of groups to which hemolytic streptococci belong is still made by the Lancefield method of precipitation in liquid medium (13,20). To make the determination more convenient, attempts to utilize immunodiffusion techniques, including the very sensitive counterimmunoelectrophoresis (CIEP) method (5,6,22), have been made. No special investigations can be found, however, aimed at presenting evidence that the reactions obtained are due to antibodies against the polysaccharide determinants specific for particular groups. Besides, immunodiffusion with sera prepared against whole microbial cells reveals cross-reactions between streptococci of different groups (22).The specific antigenic determinant of group A streptococcal polysaccharide (A-polysaccharide) is known to be the terminal group of its side chains, represented by N-acetylglucosamine, filinked (11,17). A-polysaccharide also contains a determinant, associated with rhamnose oligosaccharides, which is shared by streptococci not belonging to group A (11).A-polysaccharide gave good reactions in the gel microprecipitation test. But along with the reactions due to antibodies against the specific terminal determinant, reactions with the rhamnose determinants were also detectable. The latter reactions were found with sera of animals immunized with A-variant streptococcus (1, 2). It is known that the polysaccharide of this strain (V-polysaccharide) lacks the terminal determinants, but contains the rhamnose groups (17). Observation of the reactions between A-polysaccharide and antisera containing antibodies to Vpolysaccharide, as well as inhibition of the reactions by V-polysaccharide, indicates that Apolysaccharide preparations contain a proportion of molecules without the terminal determinant (1, 2). This may be one of the reasons for the cross-reactions between streptococci of different groups.Cross-reactions are possible also because of polyglycerophosphate (PGP) (3, 16) and the socalled non-type-specific antigens (14, 15) present in HCl extracts of streptococci belonging to group A and other groups.One should also eliminate the possibility of nonspecific reactions, since the cell wall proteins of group A streptococci, just like A-protein of staphylococci, are capable of reacting with the Fc portion of immunoglobulins (4, 12).The present investigation was undertaken to develop a procedure for the identification of group A streptococci by a gel microprecipitation test based on the use of specific antisera with high antibody levels against the terminal antigenic determinant of A-polysaccharide. ...

Immunofluorescence studies show that thymus epithelial cells react with antibodies to group A streptococcal polysaccharide.

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