Time-domain reflectometry studies on Halobacterium halobium and Halobacterium marismortui.
The dielectric properties of Halobacterium halobium and Halobacterium marismortui measured over the frequency range 1 MHz to 1 GHz are compared with a single-shell model for interfacial polarization. In the case of Halobacterium halobium, the model shows excellent agreement with the experimental data for reasonable values of membrane and cytoplasmic conductivity and permittivity. For Halobacterium marismortui however, an acceptable fit to the data can only be achieved by invoking a plasma membrane conductivity some three orders of magnitude larger than that of Halobacterium halobium and adding a second high-frequency dielectric dispersion. These observations confirm the findings of a previous study and are consistent with a scheme for Halobacterium marismortui involving thermodynamic compartmentalization of Na and K ions and the existence of a conductive plasma membrane.
Bone
S
S
Institute of Molecular and Biomolecular Electronics, University of Wales, Bangor, Gwynedd, UK.
Ginzburg
B Z
BZ
Morgan
H
H
Wilson
G
G
Zaba
B
B
D002462:Cell Membrane / Q000502:physiology; D003593:Cytoplasm / Q000502:physiology; D004553:Electric Conductivity; D004563:Electrochemistry / Q000379:methods; D006217:Halobacterium / Q000502:physiology*; D019617:Halobacterium salinarum / Q000502:physiology*; D011188:Potassium / Q000378:metabolism; D012964:Sodium / Q000378:metabolism; D013816:Thermodynamics; D013997:Time Factors
D012964:Sodium; D011188:Potassium