Nh4cl

Bacteria were grown in an adapted version of the artificial urine medium (AUM) originally described by Brooks and Keevil (1997) (link). Slight adaptations were made to decrease crystal formation in the medium and to allow for planktonic growth of the isolates. The 1× AUM contained bacto peptone L37 1.5 g/L (BD), NaHCO3 3.15 g/L, urea (Roth) 11.25 g/L, Na2SO4.10H2O 4.8 g/L, K2HPO4 1.8 g/L, NH4Cl 1.95 g/L, bacto yeast extract 15 mg/L (BD), lactic acid (Roth) 1.98 mM, citric acid 600 mg/L, uric acid 105 mg/L, creatinine 1.2 g/L, CaCl2.2H2O 4.44 mg/L, Fe(II)SO4.7H2O 1.8 g/L (Riedel), MgSO4.7H2O 368 mg/L, KH2PO4 1.43 g/L. Chemicals were from Sigma, unless stated otherwise.

All the chemicals used in the study were purchased from Sigma-Aldrich unless stated otherwise. LB medium: 10 g/l tryptone, 5 g/l yeast extract, and 10 g/l NaCl. For agar plates, 15 g/l agar was added. M9 medium: 6.8 g/l Na₂HPO₄, 3 g/l KH₂PO₄, 0.5 g/l NaCl, 1 g/l NH₄Cl, 0.34 g/l thiamine, 0.2% casamino acids (BD Biosciences), 0.4% glucose, 2 mM MgSO₄, and 100 μM CaCl₂. The LB medium for overnight culture contained ampicillin and kanamycin at concentrations of 100 μg/ml to maintain the plasmids. The mixed medium for the microfluidic culture contained ampicillin and kanamycin at concentrations of 1 μg/ml at which the cells can grow normally and the plasmids can be maintained.