The control of Listeria innocua and Lactobacillus sakei in broth and meat slurry with the bacteriocinogenic strain Lactobacillus casei CRL705

CASTELLANO PATRICIA, HOLZAPFEL WILHEM AND VIGNOLO GRACIELA

FOOD MICROBIOLOGY

Academic Press

Lugar: London; Año: 2004 vol. 21 p. 291 - 298

0740-0020

Abstract The effect of the bacteriocin-producing strain, Lactobacillus casei CRL705, in the control of Listeria innocua 7 and Lactobacillus sakei CRL1424 in MRS medium and meat slurry during the storage under vacuum at chill temperatures was evaluated. L. sakei CRL 1424 isolated from vacuum-packaged contaminated raw meat was identified as the predominant indigenous lactic acid bacterial flora. Co-inoculation of MRS broth at 8ºC with L. casei CRL705 caused growth inhibition of Lactobacillus sakei CRL1424 and Listeria innocua 7 after 10 and 4 days of storage, respectively. At 4ºC the complete inhibition of both strains occurred within 14 and 8 days for L. sakei CRL1424 and L. innocua 7, respectively. Bacteriocin activity in broth was observed to be maximal at 8ºC reaching 2130 AU ml-1 after10 days and 400 AU m1-1 after 8 days of storage, while at 4ºC maximal activities, 690 AU m1-1 and 30 AU ml-1 were obtained at 14 and 10 days respectively. Addition of the bacteriocinogenic strain to the meat slurry did not allow the growth of L. sakei and L. innocua, showing a bacteriostatic effect during 21 days of storage at 4ºC. In addition, L. casei CRL705, as a protective culture did not change significantly the pH of the meat slurry in the assayed storage conditions. The results presented here confirm that the bacteriocinogenic strain L. casei CRL705 can be used as a useful tool to improve the microbial stability and safety in the commercial meat preservation.