Further Studies upon the Effect of Various Carbohydrates on Production of Diphtheria Toxin with Special Reference to its Flocculating Titer and Final pH

Abstract

Carbohydrates were essential for production of toxic filtrates of Corynebacterium diphtheriae possessing highest potency. Glucose in small amounts is definitely superior to maltose, dextrin or glycerol as an aid to toxin production. Larger amounts of maltose than it is possible to use in the case of glucose without adjustment of pH increase the Lf titer of the filtrates of C. diphtheriae. Filtrates of the highest Lf were obtained with a combination of glucose in 0.15% and maltose in 0.3% concentration. The final pH of the filtrate does not necessarily seem to be an infallible index as to the best time of harvesting the toxin. Apparently, the toxicity of a given filtrate is largely independent of the particular final pH reaction at the end of incubation.