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The Gram-negative bacterium Lysobacter sp. XL1 secretes lytic enzymes (L1-L5) into the culture medium. Enzyme L5 is the most recently found extracellular lytic enzyme of this bacterium. The paper presents the results of the isolation and characterization of some properties of this enzyme. Thus, enzyme L5 of Lysobacter sp. XL1 is a lytic serine protease. Earlier, the enzyme was shown to be secreted into the culture medium by means of outer membrane vesicles, which possess a lytic effect towards living cells of Erwinia caratovora B15 [Vasilyeva et al., FEBS J 2008;15:3827-3835]. This work shows the action of enzyme L5 either as a vesicle component or the homogeneous enzyme L5 on a broad range of Gram-positive and Gram-negative microorganisms. Moreover, the vesicles containing this enzyme were shown to lyze the selected test cultures more efficiently than the soluble enzyme L5. It appears to be one of the first precedents of a bacteriolytic effect mediated by the action of outer membrane vesicles filled with extracellular lytic enzymes. The results suggest that the enzyme L5 of Lysobacter sp. XL1 and the vesicles containing this enzyme can be used as an antimicrobial drug.

⎯The results of detection and identification of Bacillus anthracis strains in loop-mediated isothermal DNA amplification (LAMP) reaction performed under optimized conditions with original primers and thermostable DNA polymerase are presented. Reproducible LAMP-based detection of chromosomal and plasmid DNA targets specific for B. anthracis strains has been demonstrated. No cross reactions with DNA from bacterial strains of other species of the B. cereus group were detected. The development of tests for anthrax-pathogen detection based on the optimized reaction of loop isothermal DNA amplification is planned. These tests will be convenient for clinical studies and field diagnostics due to the absence of requirements for sophisticated equipment.

Studied are phenotypic and genetic properties of anthrax agent strains, isolated from earthworms retained in infected soil for a period of 20 and 30 days. Discovered is the fact that the presence of worms in the biotope reduces the number of Bacillus anthracis spores by 30-50 %. However, the rest of the spores preserve original properties, and biological and genetic virulence dominants.

Objective of the study was to carry out comparison between the microorganisms appurtenant to six different species of Bacilli genus as regards mobility of the amplicons obtained using the primer that contained chi-sequence of Bacillus subtilis. Therewith, analyzed were 30 Bacillus anthracis strains and closely related bacilli. Cultures grew on L-agar and L-broth at 37 °C. DNA was isolated from vegetative B. anthracis and Bacillus spp. cultures introducing lysozyme and phenol de-proteinizing. In order to perform single-primer PCR constructed was ChiBs primer -5'-CTAGGAGCGGG-3'. Single-primer amplification (30 cycles) was carried out at annealing temperature of 47 °C. Comparative analysis of individual electrophoretic amplicon profiles, obtained by means of ChiBsprimer PCR, allows for identification of genetic intraspecific variability and differentiation of B. anthracis strains from the atypical ones and closely related species of bacilli.