UTILIZATION OF PROTEID AND NON-PROTEID NITROGEN 23 



to those already recorded have been obtained. These will con- 

 stitute part of a future publication from this laboratory. 



The results given in Table IV are in marked contrast to the 

 preceding. The pronounced and rapid decomposition of the 

 soluble proteins left no doubt as to the ability of gelatin-Hquefying 

 bacteria to convert them into products which no longer give the 

 biuret reaction. Sp. cholerae and Staphylococcus aureus were, 

 however, much less active than the others. 



It may be of interest to note the sparing action of glucose on 

 the proteoses and peptones in the flasks which were incubated 

 at 37°C. At room temperature (20°C.) the protein-sparing action 

 did not last beyond the first two weeks. 



III. BACTERIAL AUTOLYSIS 



The term ''autolysis" has been used somewhat indiscriminately 

 by bacteriologists. Whether it is to denote actual decomposition 

 of the intracellular proteins by the action of the bacteria them- 

 selves, or of certain enzymes, or whether it is meant to signify 

 merely a liberation of intracellular substances without change in 

 their chemical structure, is often left undetermined. The word 

 has for many years had definite significance, however, in bio- 

 chemical literature, carrying with it the idea of self-digestion, as 

 the term implies. This can, of course, be its only true meaning. 



It has frequently been shown that real bacterial autolysis is 

 a common phenomenon in organisms of the Bacillus prodigiosus 

 and Bacillus pyocyaneus type which elaborate strong proteolytic 

 enzymes (Rettger, 1904; Levy and Phersdorff, 1902), especially 

 under conditions of food deprivation and relatively high tempera- 

 tures. It is to be questioned, however, whether the so-called 

 "autolysis" of cultures of B. coli and B. typhi during long incu- 

 bation, and the liberation of endotoxin, as claimed by some 

 investigators (Conradi, 1903) is a process of real self-digestion. 



The present study of autolysis was carried on with certain 

 well-known proteolytic organisms, namely B. prodigiosus, Pro- 

 teus vulgaris, Ps. fluorescens (B. fluorescens liquefaciens, Fliigge), 

 B. subtilis and B. ramosus, and with B. typhi and several differ- 

 ent strains of B. coli representing the gelatin-non-liquefying class 



