Antilisterial activity of a crude preparation of Lactobacillus sakei 1 bacteriocin and its lack of influence on Listeria monocytogenes haemolytic activity

The antilisterial activity of a semi-purified bacteriocin from the lactic acid bacterium (LAB) Lactobacillus sakei 1 bac+, was studied at 8 and 15 °C. L. monocytogenes was grown in the presence of bacteriocin and enumerated after 0, 5 and 10 days. The bacteriocin was detected by spot-on-the-lawn assay (on the first day) and quantified by critical dilution assay on the first day and on day 10. At 8 °C, L. monocytogenes population decreased in the presence of the bacteriocin, but resistant cells were selected and reached high counts. Despite this, the final populations of L. monocytogenes were still lower where bacteriocin was present than when absent. At 15 °C, the addition of bacteriocin did not affect the multiplication of L. monocytogenes. Moreover, it was observed that the haemolytic activity of L. monocytogenes was not affected by exposure to bacteriocin of L. sakei 1.