INHIBITION OF ACTION 255 



portance of this antibiotic. The effect was believed to involve the me- 

 tabolism of nucleotides and nucleic acids (530). Penicillin had no effect 

 on the release of glucose from polysaccharides or on the oxidation of 

 glucose or pentose to acetic acid. However, when yeast sodium nuclei- 

 nate was added to a suspension of cells, a rate curve was obtained which 

 was similar to the endogenous curve j the acceleration appeared two to 

 four hours earlier, and the maximum oxidation was higher and was 

 maintained for a longer period. Penicillin was completely inhibitory to 

 this reaction. 



INHIBITION OF BACTERIOSTATIC AND 

 BACTERICIDAL ACTION 



The formation of specific chemical compounds capable of inhibiting, 

 inactivating, or even destroying bacteriostatic and bactericidal sub- 

 stances of microbial origin has been established for a number of anti- 

 biotic agents. 



Yeasts were found to contain a substance which inhibits the action of 

 sulfanilamide against S. hemolytkus as well as other streptococci and 

 pneumococci. This substance has been identified with the ^-amino-ben- 

 zoic acid referred to above. Br. abortus and certain other bacteria also 

 contain (360) a factor, designated as "p," which specifically inhibits the 

 bacteriostatic action of sulfanilamide. This factor stimulates markedly 

 the growth of many bacteria, and is not specific. The sensitivity of sulfa- 

 nilamide depends on the rate of release of the factor from the bacterial 

 cell and not on the total amount produced. This factor was believed to 

 stimulate some enzyme reaction concerned with bacterial reproduction, 

 whereas sulfanilamide inhibits this reaction. Similar factors have been 

 isolated from other microorganisms. 



To what extent antibiotic substances can be inhibited in their action 

 against bacteria still remains to be determined. Certain few facts have 

 so far been established. 



Bacteria not inhibited by penicillin were found (4, 570, 1027) 

 capable of producing a substance which destroys the growth-inhibiting 

 property of the antibiotic. The substance is enzymatic and was desig- 

 nated as penicillinase. It is produced by various bacteria, especially 

 members of the B. subtilis (221, 922) and E. coli groups. It is precipi- 



