2. Materials and methods
2.1. Bacterial culture
Before each experiment, stock cultures of L. innocua (ATCC
51742) were propagated through two consecutive 24 h growth
cycles in Brain Heart Infusion broth (Difco, Becton Dickinson,
Sparks, MD, USA) at 30 C. After incubation, L. innocua cultures,
which were in stationary growth phase, were centrifuged at
3500
g for 20 min at 4 C and washed twice in sterile saline
solution (0.85% w/v) to eliminate residual components of culture
media. The obtained biomass was then suspended in sterile saline
water, to obtain a working culture containing approximately
109 CFU/mL.