Figure 1.

Arginine contributes to μH⁺ in Proteus mirabilis. (A) Proteus mirabilis HI4320 was incubated for 60 min in 10 mmol/L MES buffer at pH 7, 5, or 2.5, and fold change in CFU mL⁻¹ were determined. Error bars indicate mean ± SD for five independent experiments. (B) Proteus mirabilis HI4320 was incubated for 60 min in 10 mmol/L MES buffer at pH 7 or 5. Viable bacteria were enumerated for MES buffer with and without 10 mmol/L CCCP and 20 mmol/L arginine. CFU mL⁻¹ were normalized to the inoculum. Error bars represent fold change over CFU mL⁻¹ in the inoculum ± SD for at least three independent experiments. ***P < 0.001 by Student's t-test compared to incubation in unsupplemented pH 5 MES.