In current study plasmids (size from 6.2 to 8.5 kb) copied with the “rolling circle” mechanism (RCR type) of the pC194 family have been identified in environmental bacteria Bacillus pumilus. It is shown that these extrachromosomal elements are widely distributed in B. pumilus bacteria circulating on the territory of Belarus (19 strains from 41 contain RCRplasmids) and they are characterized by genetic polymorphism. The most common extrachromosomal genetic elements (7.7 kb size) are identical to the plasmid pBp15.1S from the entomopathogenic strain B. pumilus 15.1. The remaining 6 type of plasmids differ from each other and from the known extrachromosomal genetic elements of genus Bacillus. In the investigated bacteria no replicons similar to pLS20 were detected.

The goal of the work was to obtain antibiotic-resistant forms of endophytic Glycine max L. (Merill) bacteria and to study their introduction potential affected by different seed treatment methods. Rifampicin-resistant variants of endophytic soybean bacteria Rhizobium radiobacter 27c and Pseudomonas fluorescens 11E preserving valuable properties were derived. Soybean seed treatment with Bradyrhizobium japonicum BIM V-501D and endophytic nitrogen-fixing Rh. radiobacter 27c, phosphate-mobilizing Ps. fluorescens 11E bacteria under model conditions promoted accumulation of nitrogen-fixing bacteria in the root, stem and leaves. The number of nodules rose by 70% compared with the mono-inoculated control; plant height increased by 19%.

Among all the existing methods of keratin decomposition, the most promising one is enzymatic hydrolysis with the use of recombinant super-producers, in particular Bacillus licheniformis, with the advantage is simplicity, low cost and a large yield of the target product. Keratinases, which specifically hydrolyze keratin-like proteins, are resistant to degradation by conventional proteolytic enzymes, and to a much lesser extent-with respect to the complex of alkaline proteases necessary for the hydrolysis of plant proteins. In turn, microorganisms with keratinolytic activity represent a potential for biotechnologies. In connection with the above, the purpose of this work was to study the possibility of creating a recombinant bacterial strain that produces highly active keratinase.

High efficiency of introducing endophytic microbiota was demonstrated upon application of nitrogen-fixing and phosphate-mobilizing bacteria for pre-sowing treatment of winter wheat seeds.