SOME EFFECTS OF IRON DEFICIENCY ON THE EXTRACELLULAR PRODUCTS RELEASED BY TOXIGENIC AND NONTOXIGENIC STRAINS OFCORYNEBACTERIUM DIPHTHERIAE

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Abstract
A kinetic study was made of the release of total extracellular protein, toxin, coproporhydrin HI and nucleic acid by certain strains of C. diphtheriae under conditions in which Fe had become limiting as a growth factor. Under these conditions, the yields and rates of total protein and of porphyrin liberated by the toxigenic C7 ([beta]) strain and by the nontoxigenic C7 strain from which it was derived by infection with [beta]-phage, were the same. Other nontoxigenic strains, whether lysogenic or not, behaved in a similar manner. Nucleic acid did not appear in the culture supernatants until growth had come to a complete standstill. In contrast to diphtheria toxin, the protein released by nontoxigenic strains was polydisperse on electrophoresis and variable in its properties. It was nonantigenic when injected into rabbits and failed to interact with diphtheria antitoxin. The significance of these findings and their bearing on the problem of relating lysogenicity to toxigenicity are discussed.