BACTERIOCINOGENIC ACTIVITY OF LACTOBACILLI FROM FERMENTED SAUSAGES

During the screening of the inhibitory activity of 254 strains of lact obacilli isolated from fermented sausages at different times of ripeni ng, 22% of the strains showed inhibition that was not related to acid or hydrogen peroxide, towards one or more indicator strains. Not all t he strains were capable of secreting the inhibitory compound in the su pernatant fluid. The characterization of the inhibitory compound from three strains showed that they were bacteriocins with a bactericidal m ode of action and a molecular weight exceeding 10 000 Da. Lactobacillu s plantarum CTC 305, CTC 306 and Lact. sake CTC 372 inhibited Listeria monocytogenes. Lactobacillus sake CTC372 was cured of two plasmids of 84.8 kbp and 41.3 kbp, losing the production and the immunity of a ba cteriocin as well as the ability to ferment lactose.