212 



NATURE OF ANTIBIOTIC ACTION 



Figure 25. Spirocheticidal action of various amounts of penicillin In vitro. 

 Inoculum, 4 x 10* organisms per milliliter. From Eagle and Musselman 

 (unpublished). 



succinic dehydrogenase. The influence of pyocyanin on bacterial respira- 

 tion, as well as its ability to function as an accessory respiratory enzyme, 

 has aroused much interest (227, 301, 854). 



A strong lytic action of some of the antibiotic substances, similar in 

 some cases to the action of enzymes, has also been indicated. This lytic 

 mechanism may be a product of the antagonized cell itself. It is to be re- 

 called that autolysis has usually been defined (865) as "the breaking 

 down and solution of some of the essential chemical constituents of the 

 cell by agencies (enzymes) originating within the cell," This does not 

 hold true, however, for most of the antibiotic substances. 



