MISCELLANEOUS ANTIBIOTIC SUBSTANCES 187 



(323). It is fixed on the bacterial cells (264), It acts primarily upon 

 the cell membrane of bacteria, the highly viscous component of the bac- 

 terial cell (the mucoids), especially the sugar linkages of the complex 

 amino-carbohydrates (601), being disintegrated by the enzyme. The 

 degradation of the bacterial polysaccharide to water-soluble products 

 ( N-acetylated amino-hexose and a keto-hexose) by lysozyme is accom- 

 panied by complete lysis of some of the bacteria. In the case of other 

 lysozyme-sensitive bacteria, such as B. subtilis, no lysis occurs 5 appar- 

 ently the morphological structure of these bacteria does not depend ex- 

 clusively on the unaltered state of the substrate for lysozyme (243), 



The formation of a lysozyme-like material was demonstrated by 

 Fleming (262) for a coccus isolated from dust. A sarcina susceptible 

 to egg-white lysozyme also was found (601) to produce an autolytic 

 enzyme similar to it. It has been suggested that the antibacterial action 

 of saliva may be due to the presence in it of antagonistic bacteria (704). 

 The lysozyme of saliva is known to act primarily upon gram-positive 

 bacteria (880). Auerswald (28) tested a large number of bacteria for 

 their ability to antagonize diphtheria and pseudo-diphtheria organisms. 

 Only the spore-forming B. mesentericus and B. subtilis groups pro- 

 duced antagonistic substances, but these bacteria were not found in the 

 saliva. Cultures of bacteria isolated from the saliva had no antagonistic 

 effect, thus proving that the action of saliva need not be due to its bac- 

 terial content. 



MISCELLANEOUS ANTIBIOTIC SUBSTANCES 



In connection with the antibiotic substances of microbial origin, at- 

 tention may be directed to certain substances, of apparently similar na- 

 ture, of plant and animal origin. No attempt will be made to discuss 

 here the antibacterial blood reactions, including antibody formation, 

 precipitin reactions, agglutination, phagocytosis j lysin formation} ac- 

 tion of various body fluids j and other animal and plant reactions against 

 bacteria and in response to bacterial infection. 



Unbleached wheat flour was shown (864) to contain a protein which 

 had bacteriostatic and bactericidal activity in vitro; although this activ- 

 ity was greatest against gram-positive organisms, it also had some ac- 



