128 



HILLEL S. LEVINSON 



400 



360 



320 



CD 



2 280 



Q 



< 



LU 240 



or 



200 



160 

 120 

 80 

 40 



NO ADDED MANGANESE 



INCUBATION TIME -HOURS 

 Fig. 7. Proteolysis in spore homogenates. Each ml of homogenate was 

 derived from 30 mg ground spores. Ninhydrin color of homogenate de- 

 veloped after centrifugation following various times of incubation at 37°C. 

 The closed circle indicates the estimated time of addition of manganous sul- 

 fate to one of the aliquots, and the distance, A, represents the time required 

 for centrifuging. The dashed portions of the curve? are. therefore, some- 

 what approximate. The magnitude of the Klett readings in comparison to 

 those of Fig. 5 is due partly to the greater amount of spore material used, 

 with consequently greater amounts of enzyme and substrate, but in greater 

 measure, perhaps, to the homologous nature of the substrate ( Levinson and 

 Sevag, 1954b). 



stimulate the germination of intact spores ( Table I ) . These stimulating sub- 

 stances are dialyzable, as are amino acids. Chromatograms show the pres- 

 ence of several amino acids in the extracts — alanine and glutamic acid be- 

 ing the most noticeable. If we measure oxygen consumption as a criterion 

 of germination, we find (Fig. 8) that we get similar curves of activity as 

 a function of concentration when we use dialyzate of extract as when we 

 use L-alanine. The stimulation obtained from 100 /xg of extract solids was 

 roughly equivalent to that obtained from 10 ng of L-alanine. Actually our 

 extracts contain only about 5 ywg L-alanine per 100 yitg of extract solids. 

 Thus, it is probable that the entire story of manganese stimulation does 



