BACTERIAL ENZYMES 113 



enzymes, but the degree of resistance acquired is never great, 

 v. Dungern l 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, find- 

 ing that the serum of a patient with osteomyelitis was over 

 twenty times as strongly inhibitory to staphylococcus enzymes 

 as was serum of normal persons. The reaction is specific, 

 cholera vibrio enzymes not being inhibited to any corresponding 

 degree. 



Autolysis of Bacteria. Autolysis occurs also in bacteria, 

 their proteolytic enzymes digesting the cell substance whenever 

 the organisms are killed by agents (chloroform, toluol, etc.) that 

 do not destroy these enzymes. Even the absence of food leads 

 to the same result, presumably because the normally existing 

 autolytic processes are not counteracted by synthesis of new 

 proteid 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 2 and Conradi. 3 The former digested anthrax 

 bacilli (in whose bodies are contained rennin, lipase, and pro- 

 tease) under toluol for several weeks, and obtained a slightl^ 

 toxic product. Conradi permitted dysentery 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 destruction of the bacterial structure by the 

 autolytic enzymes. Longer autolysis results in the destruction 

 of the endotoxins themselves by the enzymes. Rettger 4 found 

 among the autolytic products of bacteria, leucin, tyrosin, basic 

 substances, and phosphoric acid. Under favorable conditions 

 complete autolysis can occur in two to ten days. 



Brieger and Mayer 5 found that at room temperature (15 C.) 

 practically no autolysis occurs with typhoid bacilli in distilled 

 water, and the soluble products thus obtained are quite non- 

 toxic, although if injected into animals they give rise to the 

 production of agglutinins and bacteriolysins. Bertarelli 6 has 



1 Munch, med. Woch., 1898 (45), 1040. 

 2 Deut. med. Woch., 1902 (28), 879. 

 *Ibid,, 1903 (29), 26. 



4 Jour. Med. Kesearch, 1904 (13), 79. 



5 Deut. med. Woch., 1904 (30), 980. 



6 Cent. f. Bakt., 1905 (38), 584. 



