FIELD: biotechnology, microbiology, immunology, veterinary science. SUBSTANCE: invention relates to preparing the stable strain B. anthracis KM-90 retaining properties at storage, culturing in nutrient media and passages through laboratory animal bodies. The strain is obtained after the directed genetic construction including selection in population of vaccine strain B. anthracis Sterne 34F2 of spontaneous mutant with decreased proteolytic activity, temperature elimination of plasmid pX01, insertion (Tn 917) mutagenesis and selection of asporgenous mutant. The main properties of the strain are the following: asporogenicity, avirulence, low activity of proteolytic enzymes, ability to synthesize proteins of S-layer that provides the possibility of its use as the base for construction of producers of anthrax antigens and other biologically active substances that are components of anthrax vaccines and diagnostic preparations. EFFECT: strain indicated above, valuable properties.
