Abstract
In the preceding papers (Nishida, 1954a, b) the author demonstrated with static culture ofC. diphtheriaeP. W. No. 8-Tronto strain that diphtheria toxin was excreted during the stage of growth in which the most important enzyme systems of this organism were losing their activities, being followed by the increment of dead cells. Yamanaka (1954), however, demonstrated with its static culture in P. L. O. medium (Ozaki, 1953) that there could not be found so much increment of dead cells as that shown by the author. The author (1954c) also demonstrated with its shake culture in Pope's medium that the toxin could be released without the increment of dead cells.
Mitsuhashiet al. (1951) stated from the results with shake culture ofC. diphtheriaethat the most available conditions forr the growth of this organism were the most available conditions for the toxin production, provided that the medium was deficient in Fe''-ion. In 1954 Barksdale and Pappenheimer demonstrated with shake culture that the toxin production could be seen already in the stage of logarithmic growth of this organism. In 1955 Yoneda and Pappenheimer stated moreover that the toxin release was caused before the cell lysis, because no noticeable release of nucleic acid could be found in the course of the toxin excretion. The release of diphtheria toxin from the intact cells, however, is unlikely to take place in situ, because the molecule of diphtheria toxin is known to be too large to pass the intact cell membrane.
In this report the authors investigated on the relation between the toxin excretion and the grade of degeneration in the course of shake culture which did not yet show any increment of dead cells. These preliminary steps of degeneration were detected by testing the integrity of functions of its constitutive enzymes as much as possible.
