Porphyrin Formation by Yeast

IN a recent communication1 a method was described by which increased yields of coproporphyrin could be obtained from yeast preparations. To secure information on the mode of production of this pigment, we examined the possibility that breakdown of preformed chromoproteins containing protoporphyrin as a component of the prosthetic group could be responsible. Such pigments occurring in yeast are cytochrome-c, catalase and peroxidase. Although the concentration of these proteins is low, it is possible that in the yeast preparations they are synthesized continuously and then rapidly degraded to porphyrin, thus reaching dynamic equilibrium under these special conditions. To test this supposition, each individual protein was added to the standard yeast preparation and the subsequent porphyrin production examined.