COLICINS AND OTHER liACTERIOCINS 393 



found of antigenic similarities between bacteriocins and bacterio- 

 phages. Even when the same bacterial strain is lysogenic and 

 colicinogenic, for instance, no connection between its colicins 

 and phages can be demonstrated. Neither has any instance of 

 conversion from the lysogenic to the colicinogenic state or vice 

 versa been observed. 



Material antigenically related to phage has never been found in 

 sensitive or even in lysogenic bacteria, whereas some relationship 

 exists between certain colicins and the bacteria that produce 

 them. Goebel, Barry, Jesaitis, and Miller (1955) found that 

 colicin K is antigenically related to the O antigen of the pro- 

 ducing bacteria. If similar relationships could be established in 

 other systems, particularly where the colicinogenic and non- 

 colicinogenic derivatives of the same strain can be compared 

 (Fredericq, 1954a), they would have important consequences 

 concerning the relationships between bacteriocins and phages. 



One must therefore conclude that, in spite of many remarkable 

 similarities between lysogeny and bacteriocinogeny, there is at 

 present no compelling reason to believe that they are in any way 

 connected. 



