RELATIONSHIP BETWEEN TOXIGENICITY AND SPORULATING POTENCY OF CLOSTRIDIUM NOVYI

Nishida, Shoki (Kanazawa University, Kanazawa, Japan), and Gizo Nakagawara. Relationship between toxigenicity and sporulating potency of Clostridium novyi. J. Bacteriol. 89:993-995. 1965.-The less toxigenic the strains, the stronger was the sporulating potency of Clostridium novyi strains isolated. This was confirmed by investigation of the toxigenicity of substrains of C. novyi 140 possessing different degrees of sporulating potency. Atoxic strains or type C strains could be obtained from the parent type A strain (no. 140) by heat selection. This phenomenon was also observed in the other five strains. Prolonged storage of C. novyi strains also resulted in selection of cells with stronger sporulating ability and lower toxigenicity.

ISOLATION OF TOXIGENIC STRAINS OF CLOSTRIDIUM NOVYI FROM SOIL

Nishida , S. (Kanazawa University, Kanazawa, Japan), and G. Nakagawara . Isolation of toxigenic strains of Clostridium novyi from soil. J. Bacteriol. 88: 1636–1640. 1964.—The cultural conditions for toxin production by Clostridium novyi were investigated, and the optimal constituents of a proper medium were determined. A comparison of the value of this medium with other media in regard to toxin production by wild strains of C. novyi type A revealed that in this medium the organism could produce more consistent yields of potent toxin than in the other media. Isolation of C. novyi was attempted from 62 soil samples, and all were found to contain this organism. Toxigenicities of strains isolated under various conditions were examined in the above-mentioned medium, with the following results. (i) The longer the duration of the sample incubation, the less toxigenic were the strains isolated. (ii) When higher temperatures were employed to preheat the sample, fewer toxigenic strains were obtained.