126 



HILLEL S. LEVINSON 



D IC 



INCUBATION TIME- DAYS 



Fig. 5. Colorimetric estimation of proteolysis by spore extract. Curves 

 labelled I represent data with gelatin as substrate. Curves labelled II repre- 

 sent data with egg albumin. A = autoclaved spore extract; B =: spore 

 extract; C = spore extract and manganese. Spore extract equivalent to 2.7 

 mg ground spores per ml reaction system. Incubation at 30°C ( Levinson 

 and Sevag, 1954b). 



ble that the addition of manganese to any peptide or amino acid mixture 

 might increase the color developed with ninhydrin? Such does not appear 

 to be the case (Table III). 



(3) Viscosimetric method. Changes in the viscositv of gelatin also give 

 indication of proteolytic activity. All such experiments indicated that the 

 rate of loss of viscosity with manganese was about 1.5 times that Avithout 

 Mn++ (Fig. 6). 



Other pertinent information developed froiu the use of the uncetitrifuged 

 ground spores or homogenates. Incubation of the homogenates without the 



