102 NORMAN L. LAWRENCE 



used by Dr. Lawrence were undoubtedly activated intact spores, perhaps due 

 to aging during storage, where both the ribosidase and the deaminase sys- 

 tems were active. Then the incubation of these spores or their extracts with 

 adenosine resulted in its cleavage to adenine and ribose, the latter measured in 

 his particular case. Simultaneously, adenosine was probably deaminated to 

 inosine, which evidently was not followed in this particular experiment. 



Both of these enzymes were apparently active in the germinated B. cereus 

 spores employed by Dr. Powell and co-workers, as hypoxanthine, the product 

 of a ribosidic cleavage of inosine, was observed together with adenine, which 

 reportedly was not capable of deamination. Heating the germinated spores 

 gave expected ribose liberation from adenosine because the deaminase, being 

 heat sensitive, was inactivated, leaving only the ribosidase system operative. 



At this time, we feel that evidence is insufficient to permit intelligent 

 speculation on the actual significance of the ribosidase system. These ob- 

 servations only suggest that, like the alanine racemase system, it plays no 

 active part in the germination process. 



References 



Church, B. D., H. Halvorson, and H. Orin Halvorson. 1954. Studies on 



spore germination: Its independence from alanine racemase activity. 



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 Church, B. D. and H. Halvorson. 1956. Effect of heating and aging on 



germination and glucose oxidation of spores of aerobic bacilli. Bact. 



Proc. 45. 

 Harrell, W. K. and H. Halvorson. 1955. Studies on the role of L-alanine 



in the germination of spores of Bacillus terminalis. J. Bact. 69: 275-279. 

 Harrell, W. K. 1956. Studies on dipicolinic acid in spores of B. cereus var. 



terminalis. Bact. Proc. 44. 

 Krask, B. 1956. Enzymes from resting spores of Bacillus cereus var. termi- 

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monovalent anions. J. Gen. Physiol. 36: 617-629. 

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