Cultivation of Probiotic Bacteria in Media

Depending on individual nutrient requirements, different media were used for pre-cultivation of the different strains (Additional file 1: Table S1). All strains of P. freudenreichii and L. paracasei subsp. paracasei NCC 2511 and were grown in de Mann‐Rogosa‐Sharpe (MRS) medium, containing per litre: 52.0 g of MRS broth (Sigma-Aldrich, Steinheim, Germany) and 1.0 mL of Tween-80 (Sigma-Aldrich). In selected experiments, MRS medium was also used as main culture medium. In some of these studies, CoCl₂ (50 µM) and dimethylbenzimidazole (DMBI, 100 µM) were added to the MRS medium [24 (link), 74 (link)]. B. amyloliquefaciens NCC 156 was cultivated in modified tryptic soy broth (TSB) medium. It contained per litre: 17.0 g of tryptone (Becton Dickinson), 5.0 g of NaCl, 3.0 g of soytone (Becton Dickinson), 2.5 g K₂HPO₄, and 1.0 mL of 30% silicone antifoam (Sigma-Aldrich) [28 ].