TABLE 2.

Zero-current membrane potentials (Vm) of diphytanoyl phosphatidylcholine-n-decane membranes in the presence of B. duttonii Oms38 measured for a fivefold concentration gradient of different electrolytesa

ElectrolyteVm (mV)Pcation/Panion
KCl−14.00.41
LiCl−22.40.24
KCH3COO (pH 7)−8.60.58
  • a Vm is defined as the difference between the potential at the diluted side (100 mM) and the potential at the concentrated side (500 mM). The aqueous electrolyte solutions were buffered with 10 mM Tris-HCl (pH 7.5); the temperature was 20°C. The permeability ratio Pcation/Panion was calculated using the Goldman-Hodgin-Katz equation (13) from at least two individual experiments.