Boticinogeny and actions of the bacteriocin

Abstract

The bacteriocin, boticin E, was produced by only a few strains of those clostridia which are nontoxigenic but otherwise identical to Clostridium botulinum type E. Boticin preparations from four different strains had identical spectra against indicator cultures. Experiments with bacterial lawns showed boticin to be sporostatic for all tested nonproteolytic C. botulinum (types B, E, and F) and nontoxigenic type E-related strains which included the producing strains as well as those different from type E in the fermentation of one to three carbohydrates. Boticin had no detectable effect on vegetative cells of boticinogenic strains but killed those of all other strains whose spores were sensitive. Cultures that were growing in an agar medium were more sensitive to the bacteriocin than those growing in broth. Vegetative cells of indicator strains adsorbed boticin, but cells of a boticin-resistant mutant did not. Boticin did not lyse suspensions of vegetative cells which had been killed previously by exposure to air but lysed actively growing protoplasts and L-forms of a strain whose normal vegetative cells are susceptible to lysis. Sporostasis resulted from inhibition of germination rather than of outgrowth. Proteolytic strains of C. botulinum (types A, B, and F) were resistant to boticin E.