[Effect of calcium hypochlorite on Bacillus anthracoides spores]

The sublethal dose of calcium hypochlorite (CH) of 0.2--0.3 mg/ml active chlorine did not cause, after 5 min, morphological changes in the spores of Bacillus anthracoides which could be detected by phase contrast microscopy, or a decrease in the content of dipicolinic acid (DPA) in the spores. Further cultivation of the spores treated with the sublethal dose of CH om MPA resulted in a delay of changes which were typical of normal germination process (swelling, loss of light refraction, decrease in DPA content). The action of the lethal dose of CH (0.2--0.3 mg/ml active chlorine during 1.5 hr or 5.6 mg/ml active chlorine during 1 hr) causes a decrease in light refraction, changes in the dimensions of spores, and a decrease in the content of DPA in the spores by a factor of 4--5. A sharp decrease in the content of DPA in the spores may characterize not only their germination but also their death caused by lethal doses of the chlorine containing disinfectant.