Lp0037

In initial experiments, four different culture media were evaluated to identify the culture medium that best facilitates filamentous growth of biofilm as microcolonies, each at three different concentrations: 1 × YPD (10 g L⁻¹ Yeast extract [Oxoid; LP0021], 20 g L⁻¹ Peptone [Oxoid; LP0037], 20 g L⁻¹ Dextrose [Difco, 215530; Becton, Dickinson and Company]), 1× Mueller Hinton Broth (LAB114; LabM), 1 × M19 without NaCl (pH 6.1, 9.4 g L⁻¹ Peptone [Oxoid; LP0037], 4.7 g L⁻¹ Yeast extract [Oxoid; LP0021], 2.4 g L⁻¹ Beef extract [Difco; 212610], 10 g L⁻¹ Glucose monohydrate [Merck; 49161]) and 0.5 × Def4 (pH 7). The 0.5 × Def4 media were based on the 0.5 × Def4 reported by Correa et al. (2012 (link)) modified as follows: 0.65 g L⁻¹ KH₂PO₄, 2.75 g L⁻¹ (NH₄)₂HPO₄, 0.31 g L⁻¹ MgSO₄ · 7H₂O, 0.45 g L⁻¹ citric acid, 10.20 mg L⁻¹ Fe(III) citrate hydrate, 0.525 mg L⁻¹ H₃BO₃, 2.50 mg L⁻¹ MnCl₂ · 4H₂O, 2.10 mg L⁻¹ EDTA · 2H₂O, 0.26 mg L⁻¹ CuCl₂ · 2H₂O, 0.44 mg L⁻¹ Na₂MoO₄ · 2H₂O, 0.44 mg L⁻¹ CoCl₂ · 6H₂O, 1.30 mg L⁻¹ Zn acetate · 2H₂O, 1.0 g L⁻¹ NaCl, 10 g L⁻¹ MOPS, 20.0 g L⁻¹ fructose, supplemented with 147.0 mg L⁻¹ CaCl₂ · 2H₂O. YPD, LAB114 and M19 were tested at 1×, 0.5× and 0.25× concentrations, whereas Def4 was tested at 0.5×, 0.25× and 0.125×. The media were diluted in sterile ion‐free water prior to use to obtain the desired concentration.