Ability of Bdellovibrio bacteriovorus 109J to Lyse Gram-Negative Food-Borne Pathogenic and Spoilage Bacteria

Abstract

Bdellovibrios are a group of aerobic, predatory bacteria which attack, penetrate and grow in many species of gram-negative bacteria, causing the lysis of the invaded prey organism. Bdellovibrio bacteriovorus strain 109J varied in its ability to lyse 32 bacterial strains comprising six genera of food-borne pathogens and spoilage organisms. The reduction in the levels of the prey bacteria ranged from 0.1 to 7.7 log-values after 7 h of incubation at 30°C. Escherichia coli strain 2239-69 (pathogenic serotype 026:H11) was lysed most effectively at temperatures between 30 and 37°C, however, lysis also occurred at 12 and 19°C when the incubation period was extended to 24 h. Bdellovibrio bacteriovorus was effective in reducing the level of E. coli 2239-69 at pH 5.6 to 8.6. Increasing the Bdellovibrio: E. coli ratio resulted in a more rapid E. coli reduction. This study demonstrated the potential usefulness of bdellovibrios for the biological control of pathogenic and spoilage organisms in foods.