Plasmid-determined Bacteriocin Production by Rhizobium leguminosarum

Abstract

Bacteriocin production by 97 isolates of R. leguminosarum was investigated and 2 types of bacteriocins were identified and designated small and medium. Three isolates appeared to carry determinants of medium bacteriocin production which were self-transmissible at frequencies of 10-1-10-2, suggesting the presence of bacteriocinogenic-plasmids in these strains. The mobilization of chromosomal genes was associated with transfer of the abacteriocinogenic plasmids. Indirect evidence that the production of small bacteriocins may be determined by plasmids in 3 other strains is presented.