Inhibition by Lactobacillus sakei of other species in the flora of vacuum packaged raw meats during prolonged storage

The abilities of five Lactobacillus sakei strains and one Lactococcus lactis strain to retain inhibitory activity against several target organisms in the flora of product during 12 weeks storage of vacuum-packaged lamb and beef was investigated. L. sakei strains were generally found capable of developing dominant populations on both beef and lamb. L. lactis 75 grew poorly on lamb did not inhibit co-inoculated Brochothrix thermosphacta. Lamb inoculated with the Sakacin-A producer L. sakei Lb706 had lower Listeria monocytogenes populations than lamb inoculated with a bacteriocin-negative variant. In beef packs inoculated with Clostridium estertheticum spores and L. sakei strain 27, 44 or 63, the development of blown-pack spoilage was delayed by up to one week. Campylobacter jejuni inoculated onto beef was recovered from fewer packs when it was co-inoculated with 3000 CFU cm⁻² of L. sakei strain 27, 44 or 63. Observed inhibition did not always correlate with inhibition observed in earlier media-based studies, supporting the view that functionality identified using simple media-based screening methods may not be replicated in the complex environment of stored foods, and vice-versa. These findings further define a set of L. sakei strains with potential for the extended bio-preservation of minimally processed fresh beef and lamb.