Stock cultures of each organism were maintained at −20 °C in the
appropriate cultivation broth containing 20% (v/v) glycerol. The two
Salmonella strains and the two Staphylococcus sp. were cultivated in
Tryptone Soy Broth (TSB) and Tryptone Soy Agar (TSA) (Pronadisa,
Madrid, Spain). Man-Rogosa–Sharpe (MRS) broth and agar (Pronadisa),
adjusted to pH 5.7 was used for the growth of L. plantarum.