炭疽菌培養液中の酸沈澱物質の抗原性に関する研究

I. 培養液ならびにその分画の抗原性

抄録

It is a well-known fact that Bacillus anthracis produces in the culture medium a variety of substances, such as polysaccharide, protective antigen and toxin, and of these the in vitro antigenicity of the polysaccharide has been studied extensively, but that of the other substances has been rather few and not clear.
In this study, the culture fluid of B. anthracis after the growth of the organism was separated from the cells by centrifugation and fractionated into both the acid-precipitating fraction (A-P substance) and the supernatant fluid fraction by adjusting the pH to 3.8, then the antigenicity of and antigenic relationships among the culture fluid and the fractions were examined. Parallel experiments were also carried out by the use of a strain of B. megaterium, the extract of which precipitates with anti-B. anthracis serum in a higher titer.
The culture fluid of B. anthracis strongly precipitated not only with anti-B. anthracis serum but also with anti-B. megaterium serum. The supernatant fluid of the same organism also gave strong reactions with both antisera. Both the culture fluid and the supernatant fiuid of B. megaterium also gave strong reactions not only with anti-B. megaterium serum but also with anti-B. anthracis serum. The A-P substance of B. anthracis, however, precipitated only with anti-B. anthracis serum in a lower titer and it did not precipitated with anti-B. megaterium serum. The A-P substance of B. megaterium precipitated neither with anti-B. megaterium serum nor with anti-B. anthracis serum.
The culture fluids of both B. anthracis and B. megaterium were positive to the biuret and Molisch tests. The A-P substances of both organisms were positive to the biuret test and very weakly positive or almost negative to the Molisch test, while the supernatant fluids of these organisms were negative to the biuret test and positive to the Molisch test.