Sensitivity of some Erwinia carotovora serogroups to macromolecular bacteriocins

Representative strains from each of 18 Erwinia carotovora serogroups were tested for bacteriocin activity. Eight bacteriocin producing strains were found and the bacteriocins partially purified by ammonium sulfate fractionation and high-speed centrifugation. Bacteriocins from all eight strains were morphologically similar to bacteriophage tails. Specific absorption of bacteriocins from one of the antagonistic strains to sensitive bacterial cells was demonstrated with electron microscopy. In four of the serogroups tested each strain was sensitive to only one or two of the bacteriocins while in other serogroups sensitivity varied. Strains of both E. carotovora var. atroseptica and E. carotovora var. carotovora were sensitive to the same bacteriocins, but the two serogroups of var. atroseptica could be differentiated from each other on the basis of sensitivity to one bacteriocin.