104 NORMAN L. LAWRENCE 



was previously thought. One interesting feature of the latter has been their 

 ability to alter their phenotype through induced enzyme synthesis. Several 

 experiments illustrate also that the enzyme pattern of the spore is not limited 

 to those required for the maintenance and breaking of dormancy. This was 

 first indicated by Martin Pollock who studied the rate of induced penicillinase 

 synthesis during germination of spores obtained from penicillir? induced 

 vegetative cells and non-induced cells. The former produced penicillinase 

 more rapidly than the latter, indicating that the penicillinase-forming system 

 was carried through the spore state. Dr. Knox Harrell (unpublished results) 

 in my laboratory studied this same problem and found that extracts of spores 

 produced from penicillin-induced cells contained penicillinase. The intact 

 spores were inactive on penicillin. It seems unlikely that this enzyme plays 

 a role in dormancy or germination. These results further suggest that some 

 of the differences in germination requirements observed in the same or related 

 spore species are a reflection of the differences in enzyme patterns of the 

 vegetative cells which are carried into the spore cytoplasm at the time of 

 sporulation. 



MuRTY: At the time we were running these experiments it was unfortu- 

 nate that I could not get any inhibitor other than p-fluorophenyl alanine. 

 However, we shall try other inhibitors also. I do not know if the inhibition 

 of p-fluorophenyl alanine can be reversed by phenyl alanine. However, we 

 know that the activation by L-alanine is completely antagonized by D-alanine, 

 a phenomenon also observed by Murrell. 



Gerhardt: I am very strongly reminded of and would like to point up 

 to the group the sometimes very close analogy between what one sees here 

 in spores and in some of the earlier, and now continuing, very elegant ex- 

 periments of J. Gordin Kaplan, with Avhom many of you may not be familiar. 

 His observations of the heat stable catalase of yeast and its activation on the 

 rupture or solvent extraction of the yeast cell, which he refers to as the 

 Euler effect, may be comparable to what one often sees in spores. I think the 

 interesting point which he has demonstrated, and which may serve as a model 

 for experiments here, is his recreation of the heat stability of yeast catalase 

 by absorption of the isolated enzymes on lipid and I understand more re- 

 cently on RNA. That is, he has been able to activate the enzyme and then 

 deactivate it at will in an artificial system. One wonders here if one could 

 activate one of these spore enzymes by heat, possibly create a model system 

 with dipicolinic acid, and then deactivate the enzyme by absorption on that 

 system. 



