AUTOLYSIS OF BACTERIA 113 



Other observers have found that immunization against Hving or dead 

 bacteria leads to the production of substances antagonistic to their 

 enzymes, but the degree of resistance acquired is never great, v. Dun- 

 gem" found that the serum of animals infected with various bacteria 

 prevented digestion of gelatin by the enzymes obtained from cultures 

 of the same species of bacteria. He applied this fact to the diagnosis 

 of infectious conditions, finding that the serum of a patient with 

 osteomyelitis was over twenty times as strongly inhibitory to staphy- 

 lococcus enzymes as was serum of normal persons. The reaction is 

 specific, cholera vibrio enzymes not being inhibited to any correspond- 

 ing degree. 



Kantorowicz^ and de Waele^ state that bacteria contain an intra- 

 cellular anti-protease which, with most bacteria, holds in check the 

 proteolytic action; only with the liquefying bacteria are the proteases 

 in excess. Bacteria grow well in strong solutions of enzymes, and with- 

 out destroying the enzymes (Fermi).'" After Gram-negative bacteria 

 have been heated to 80° they are readily digested by trypsin, pepsin 

 or leucocytic proteases; but Gram-positive bacteria are resistant even 

 after heating. This is ascribed by Jobhng and Petersen" to the un- 

 saturated fatty acids, which are present in greater amounts in Gram- 

 positive bacteria. 



Autolysis of Bacteria. — Autolysis occurs also in bacteria, their pro- 

 teolytic enzymes digesting the cell substance whenever the organisms 

 are killed by agents (chloroform, toluene, etc.) that do not destroj' 

 these enzjaiies, and which, being fat solvents, may facilitate digestion 

 by removing the inhibitory lipoids. Even the absence of food leads 

 to autolysis, presumably because the normally existing autolj'tic 

 processes are not counteracted by synthesis of new protein material; 

 hence, autolysis occurs when bacteria are placed in salt solution or 

 distilled water. Although it had been known for many years that 

 yeast cells digest one another when there is nothing else for them 

 to live upon, the first definite study of bacterial autolysis seems to have 

 been made by Levy and Pfersdorff'^ ^nd Conradi.'^ The former 

 digested anthrax bacilli (in whose bodies are contained rennin, lipase 

 and protease) under toluene for several weeks and obtained a slightly 

 toxic product. Conradi permitted dj'sentery bacilli and typhoid 

 bacilli to digest themselves in normal salt solution for twenty-four to 

 forty-eight hours at 37° C., and obtained in this way the soluble, highly 

 poisonous endotoxins of the bacteria, which are liberated by the de- 

 struction of the bacterial structure by the autolytic enzymes. Longer 



^ Miinch. med. Woch., 1898 (45), 10-10. 



8 Miinch. med. Woch., 1909 (56), 897. 



9 Cent. f. Bakt., 1909 (50), 40. 



1" Arch. FarmacoL, 1909 (8), 481. 

 "Jour. Exp. Med., 1914 (20), 321. 

 1- Deut. med. Woch., 1902 (28), 879. 

 13 Ibid., 1903 (29), 26. 



