FIELD: microbiological industry, agriculture, food industry. SUBSTANCE: method involves culturing bacterium Bacillus subtilis on semipermeable diaphragm surface placed on solid nutrient medium to maximal biomass accumulation and transfer of bacteria to spore form by cell cooling to temperature 10 C, not above, and keeping at this temperature for 24 h, not less, followed by bacterium spores mixing with filling agent. Before mixing with filling agent spores are separated from semipermeable diaphragm. Filling agent: a mixture of sugar and starch at ratio bacterium spore biomass and starch 1:1, not above, and bacterium spore biomass and sugar 1:50, not above. Method can be used for preparing dry bacterial preparations as a spore form. EFFECT: enhanced purity, simplified technology. 5 cl, 1 tbl
