Abstract
Park and Williams, 1 following the work of Spronck, 2 reported that small amounts of glucose added to the broth aided in production of potent toxic filtrates from Corynebacterium diphtheriae. They warned at the same time that an excess of glucose sufficient to cause too great a degree of acidity would inhibit the development of the toxin. T. Smith 3 also found that small quantities of dextrose were favorable to toxin production, provided the muscle sugar had been removed from the broth by fermentation. Recently Locke and Main 4 and Ramon 5 have again called attention to the use of glucose in the production of high-titred diphtheria toxin.
We have studied the effect of a number of carbohydrates, fermentable by C. diphtheriae, on the production of toxic filtrates of high Lf∗ unitage. We are reporting here only those experiments in which glucose and maltose have been used to enrich the culture medium.
The culture filtrates (Park-Williams No. 8 strain of C. diphtheriae) were obtained after incubation from 48 hours to 5 days at 37.5°C., no preservative being added. The pellicles were grown in every case in one litre flasks containing 250-300 cc. of broth as used by Povitsky. 7 The initial inoculum consisted of one large loopful of an actively growing pellicle, the seed culture having been maintained previously by rapid transfer, twice daily. Apparently little harm was done to the pellicles by manipulation of the flasks in adding the sugars and adjusting the pH of the culture fluid. Toxins were obtained within 48 hours from cultures grown in this basic medium which had 6.5 Lf units per cc. and approximately 500 M.L.D. per cc.
The two sugars have been utilized as follows: (1) Fractional amounts of either glucose or maltose were added to the growing culture from one to 3 times daily for 48 to 72 hours, each addition of sugar being preceded by titration and adjustment of the culture fluid to pH 8.0.
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