o 



INCUBATION TIME- DAYS 



Fig. 6. Viscosimetric demonstration of gelatin hydrolysis by spore ex- 

 tracts. Open circles, gelatin and autoclaved extract; triangles, gelatin and 

 spore extract; squares, gelatin and spore extract with manganese. Incuba- 

 tion at 30°C. 



addition of other protein, resulted in an increase in the intensity of the nin- 

 hydrin color ( Fig. 7 ) . Not only that, but manganese accelerated and in- 

 creased the proteolysis. This seems to us to be highly significant, since it 

 could be evidence that the spore material itself can serve as substrate for 

 the proteolytic enzymes of the spores. You may recall that in the proteo- 

 lysis of gelatin and egg albumin by spore extract I Fig. 5) the incubation 

 time was in days, and the Klett reading reached 90 in three days. In the 

 case of these spore homogenates, however, the incubation period is in hours 

 and the Klett readings go much higher. We attribute this faster proteolysis 

 to the substrate's being, in this case, homologous for the enzymes concerned, 

 thus permitting the breakdown to proceed much faster and to a greater ex- 

 tent* than did the breakdown of the heterologous egg albumin and gelatin 

 substrates. 



As I have previously shown, spore extracts contain substances which 



