UTILIZATION OF PROTEID AND NON-PROTEID NITROGEN 29 



TABLE X 



Action of autolysis material (1.0 cc.) on solution of Witle's peptone {5 cc. of a o per 

 cent solution). Gelatin liquefiers 



B. prodigiosus 



B. prodigiosus II ... . 



Prot. vulgaris 



Control 



BIURET REACTIONS AND COLOR COMPARISONS WITH 

 PEPTONE CONTROL 



1st day 2nd day 4th day 6th day 12th day 20th day 



5.0 

 5.0 

 5.0 

 5.0 



4.0 

 4.0 

 4.0 



2.0 

 2.5 

 3.0 

 5.0 



1.0 

 2.0 



0.5 

 1.5 

 5.0 



Faint 

 1.0 

 5.0 



Note: The controls were prepared by adding 1 cc. of distilled water to 4 cc. 

 of the given peptone solutions. 



TABLE XI 



Action of autohjsis material (1 cc.) on solution of Witte's peptone {5 cc. of a 0.25 per 

 cent solution). B. subtilis and B. coli comparison 



Note: This experiment was repeated with larger amounts of peptone. The 

 results were practically the same as in this table. 



The above tables show clearly the ability of bacteria to 

 digest themselves. This property appears to be confined, how- 

 ever, to organisms which are known to elaborate a proteolytic 

 enzyme — the gelatin-liquefying group. Not only do the organ- 

 isms of this group rapidly destroy their own protein under 

 favorable conditions of autolysis, but they readily attack and 

 decompose egg albumin, peptones and partially purified pro- 

 teoses when the autolyzing materials are brought in contact 

 with these foreign proteins. 



On the other hand, the gelatin-non-liquefying organisms em- 

 ployed in these experiments were unable to effect any change in 

 the protein content of the respective suspensions, at least in so 

 far as may be judged by the biuret tests. Furthermore, other 



