2.2. Bacterial strains and culture conditions
Enterococcus mundtii Tw56 was stored in MRS broth. Indicator microorganisms were stored in MRS or Tryptone Soy broth, according to the requirements of each microorganism ( Table 1). Both media were supplemented with 10% (w/w) glycerol (Sintorgan S.A., Buenos Aires, Argentina) and 10% (w/w) skim milk. Cultures were stored at −30 °C. Before the use, they were grown twice in the appropriate culture media at 30 °C for 18 h. Mentioned media were purchased from Biokar Diagnostics (Beauvais, France).