Synergistic mode of action of mesenterocins 52A and 52B produced by Leuconostoc mesenteroides subsp. mesenteroides FR 52.

Few studies have been published on the effects of two bacteriocins combinations and particularly on combinations of two bacteriocins with different structures produced by the same strain. In this work, the actions of mesenterocin 52A (class IIa) and mesenterocin 52B (class II), produced by Leuconostoc mesenteroides subsp. mesenteroides FR 52, were studied on strains susceptible to only one bacteriocin or to both. In broth, combination of mesenterocins enhanced the adaptation time of the strain susceptible to the both mesenterocins (48 h vs 17 h with only one bacteriocin). In agar medium, mesenterocins displayed, as expected, a synergistic effect on this strain (FIC(index) < 1), but also on the two strains susceptible to only one mesenterocin. This original result was probably due to membrane composition modifications induced by the mesenterocin that enhanced bacteriocin action. Thus, this hurdle technique seems to be interesting in food preservation in terms of minimizing bacteriocin concentrations.