116 G. G. KRISHNA MURTY 



was of interest to note that the endogenous respiration of spore reserves 

 was higher in heat-activated than in germinated spores. 



We have previously shown that spores can be heat- activated to oxidize 

 glucose without germinating. These findings suggested that in the alanine- 

 adenosine germinating system activation of glucose oxidation preceded 

 germination. Previous studies by us demonstrated that unheated spores of 

 B. cereus var. terminaUs would not germinate in the presence of adenosine 

 and low concentrations of glucose. The ability of unheated spores in such 

 a mixture to activate glucose oxidation in the absence of germination was 

 observed and reported earlier (Church and Halvorson, 1956). If either 

 higher concentrations of glucose were added or a heat -activation applied 

 after 95-minutes of incubation, a rapid germination was observed. The rate 

 of this oxidation is again related to the age of the spore. 



The biochemical basis of the process of germination is ultimately re- 

 stricted to the enzymatic constitution of the dormant spore. An understand- 

 ing of the state of dormancy and its loss during germination requires knowl- 

 edge not only of the enzymatic pattern of the spore but also of the factors 

 controlling enzymatic activity in vivo. 



The spore enzymes described thus far fall into two groups: one whose 

 activity is recognizable in the intact dormant spore, and the other requir- 

 ing rupture of the spore. Racemase, adenosinedeaminase, ribosidase, and 

 a heat resistant catalase are examples of the former; pyrophosphatase, glu- 

 tamic-aspartic transaminase, and heat sensitive catalase belong to the lat- 

 ter group. The glucose-oxidizing system described in our work and in the 

 work of Murrell (1955), and Murty and Halvorson (1956) falls into still 

 another class of dormant enzymes whose activity in vivo requires appro- 

 priate activation. Since activation precedes germination, a study of the 

 activation process itself should provide a useful approach to the overall 

 problem of germination. 



The properties of the glucose-oxidizing svstem in intact spores described 

 here can be diagrammatically represented in the following manner: 



Aging prior to Heat or 



activation adenosine 



Inactive \ Dormant ^ Active 



enzyme system ^ enzyme system >;; enzyme system 



Prolonged aging Short 



after activation storage periods 



Thus the enzyme system may be either inactive, dormant, or active in the 

 intact spore. The dormant enzyme system was that glucose-oxidizing ca- 



