Inhibition of Listeria monocytogenes by Carnobacterium piscicola in vacuum-packaged cooked chicken at refrigeration temperatures

Listeria monocytogenes inhibition by bacteriocinogenic Carnobacterium piscicola DX or nonbacteriocinogenic C. piscicola 2818 was examined in vacuum-packed minimally processed chicken cubes with gravy at 4, 8 and 15C. C. piscicola DX and C. piscicola 2818 at 10(4) CFU/g were coinoculated individually with a pool of three Listeria monocytogenes strains at 10(2) CFU/g. At 4 and 8C, C. piscicola DX inhibited growth oft. monocytogenes by 3 logs, significantly (p < 0.05) more than did C. piscicola 2818. At 15C both C. piscicola strains inhibited L. monocytogenes by one log cycle. The pH of all inoculated systems decreased from an initial pH of 6. 14 to final values ranging from 6.06 to 5.65 depending on the inocula used. Bacteriocin was detected in the systems coinoculated with C. piscicola DX. These studies demonstrate that lower temperatures and bacteriocin production enhanced L. monocytogenes inhibition by C. piscicola.