Bacteriocin activity of Tn 5 insertion mutants of the Pectobacterium carotovorum subsp. carotovorum strains: 1, Serratia sp. (marker); 2, TH12-2 (Tn5 insertion mutant, flhC::Tn5); 3, H-rif-8-6 (parent); 4, E. coli 1830/pJB4JI (containing Tn5). The unlabeled strains are all Tn5 insertion mutants of the H-rif-8-6 parental strain. Strain Ea1068 was used as an indicator for bacteriocin activity.