BACTERIOCIN INHIBITION OF CLOSTRIDIUM-BOTULINUM SPORES BY LACTIC-ACID BACTERIA

Twenty-three strains of lactic acid bacteria were tested by deferred antagonism methods for bacteriocin-like activity against types A and B spores from 11 proteolytic and nonproteolytic Clostridium botulinum strains. Pediococcus pentosaceus ATCC 43200, Pediococcus pentosaceus ATCC 43201, Lactococcus lactis subsp. lactis ATCC 11454, Lactobacillus acidophilus N2, Lactobacillus plantarum Lb75, Lactobacillus plantarum Lb592, and Lactobacillus plantarum BN exhibited bacteriocin-like inhibition of all C. botulinum strains tested. By excluding inhibition due to hydrogen peroxide, acid, and lytic phage and confirming their proteinaceous nature, the inhibitors were confirmed as bacteriocins. The minimum inhibitory cell concentrations (MICC) required to produce 1 mm radius inhibition zones were determined by direct antagonism testing. Only strains 43200, 43201, 11454, and N2 were inhibitory when cultured simultaneously with the botulinal spores. The MICCs of strains antagonistic to C. botulinum spores by simultaneous testing ranged between 1.6 x 10(5) and 4.7 x 10(7) CFU/ml. Based on the MICCs, P. pentosaceus 43200 was most inhibitory to C. botulinum.