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 Lforms 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. on August 1, 2020 by guest

Low-Temperature Irradiation of Beef and Methods for Evaluation of a Radappertization Process

“…Our results (Tables 2 and 3) reflect a complex phenomenon which may be due to one or more series of events occurring either simultaneously or sequentially: (i) the secretion into the food substrate by one or more strains of C. botulinum of a boticin-like substance, a bacteriocin, which is usually antagonistic against a limited number of strains of the same or closely related species of organism. Boticin production by type A, B, C, and E strains has been reported previously (1,12,22,37,40). A preliminary investigation in our laboratory seemed to indicate such a possibility with our strains.…”

“…An inoculated, irradiated beef pack (1,240 cans) study was conducted for the determination of microbiological safety for unrestricted human consumption. Each can contained a mixture of 106 spores of each of 10 strains of Clostridium botulinum (5 type A and 5 type B), or a total of 107 spores/can.…”

Numerical Taxonomy of Clostridium botulinum and Clostridium sporogenes Strains, and Their Susceptibilities to Induced Lysins and to Mitomycin C

“…Anastasio et al [1] reported that boticin E produced by C. botulinum E-like strains inhibited germination of spores obtained from nonproteolytic C. botulinum types B, E, and F, as well as nontoxigenic type E-related strains which included the boticin E-producing strains, but did not from proteolytic strains of C. botulinum types A, B, and F. Boticin E had no detectable effect on vegetative cells of boticinogenic strains but killed those of all other strains whose spores were sensitive. Contrary to the boticin E, the induced lysin produced in the lysate of C. botulinum A190 strain has specificity to strains grouped in the phenon I.…”

Group a Streptococcal Bacteriocin

“…The bactericidal activity of streptocin A in liquid media, including its effect on RNA degradation, was shown to be significantly less than that of preparations of a staphylococcal bacteriocin having an identical inhibitory titer against the indicator strain in lawn culture assays. Several other investigators have similarly noted that the action of boticins (30), pesticins (31), or colicins (32) may also be substantially greater against susceptible organisms grown on agar medium than when grown in broth. In any such studies it is important to distinguish carefully between the determination of general inhibitory activity (including bacteriostatic effects) in lawn culture assays and the measurement of specific bactericidal activity from viable counts of survivors after exposure to the bacteriocin.…”