Table 3.

Zero-current membrane potentials, V_m, of DiPhPC–n-decane membranes in the presence of supernatant of B. cereus F837/76 ∆nheABC measured for 5-fold gradients of different salts. V_m is defined as the difference between the potential at the diluted side and the potential at the concentrated side. The aqueous salt solutions were buffered with MES and had a pH of 6, if not indicated otherwise; T = 20 °C. The permeability ratios P_cation/P_anion were calculated using the Goldman–Hodgkin–Katz equation as the mean (± SD) of at least three individual experiments [33].

Electrolyte	Permeability Ratios Pcation/Panion	Vm (mV)
KCl	3.3	19.1 ± 0.8
LiCl	2.3	13.7 ± 0.5
KCH3COO (pH 7)	5.0	25.5 ± 0.6