DORMANCY OF BACTERIAL ENDOSPORE 



81 



State of these enzymes, the approach to the problem is largely 

 guided by experimental opportunities. This was provided by 

 Harrell and Mantini^^ by the finding that both the glucose 

 oxidizing capacity as well as the release of DPA was propor- 

 tional to the length of the heat shock period. These concurrent 

 activations suggested that the two phenomena were closely 

 related. It was thought that during heat activation perhaps 

 an enzyme inhibitor was removed or an enzyme stimulator 

 released which would affect the activity of the overall respiratory 

 system. 



Together with HarrelP^' ^^ we observed in extracts of heat- 

 activated spores that the oxidation of glucose or of DPNH 

 could be stimulated three fold by the addition of DPA, as shown 

 in Fig. 4. DPA was not metabolized nor was the activity of the 



Glucose oxidation 



DPNH oxidation 



Minutes 



Fig. 4, Stimulation of glucose and DPNH oxidation by dipicolinic acid. 

 The Warburg vessels contained: glycylglycine buffer, pH 7.3, 75 //moles; 

 enzyme fraction with 4 mg protein; DPA as indicated and (a) glucose, 

 20 //moles ;DPN, 0.7 //moles; (b) DPNH, 10 //moles. Final volume. 1.8 ml. 

 Center well contained 0.2 ml of 20 °„ KOH. Incubation temperature, 30". 



References p. 94 



