STUDY OF OPTIMAL CONDITIONS FOR THE FORMATION OF THE ANTHRAX EXTRACELLULAR PROTECTIVE ANTIGEN IN A MILK MEDIUM (IZUCHENIE OPTIMALNYKH USLOVII OBRAZOVANIYA SIBIREYAZVENNOGO VNEKLETOCHNOGO ZASHCHITNOGO ANTIGENA NZ MOLOCHNOI SREDE)

For the obtaining of extracellular protective anthrax antigen, a medium was developed the nutrient basis of which was the cow's milk. It was established that glucose served as the most favorable source of energy for the production of the protective antigen in a milk medium. Sodium bicarbonate was a necessary component in the milk medium in obtaining in it of the anthrax antigen, and carried out the role of regulator of physical-chemical processes in the medium. Anthrax microbes began producing the protective antigen in the stage of logarithmic reproduction after the 10-14th hour of incubation; its accumulation reached the maximum after 38-42 hours of cultivation. Extracellular protective antigen is formed in the medium in the process of the metabolic activity of microbes, and is not the product of their lysis. It was established that for the concentration of the protective anthrax antigen a method can be utilized for its precipitation using two volumes of ethyl alcohol at pH=6.0. (Author) Trans. of Zhurnal Mikrobiologii, Epidemiologii i Immunobiologii (USSR) v33 n4 p9-14 1962.