FINE STRUCTURE OF THE RED MEMBRANE OF Halobacterium halobium (R1)

Abstract

The cell wall and plasma membrane of Halobacterium halobium (R1) were examined with electron microscopy of thin sections and “freeze replicas. Deep-etched replicas from freshly frozen-fixed specimens showed filamentous structures, arising in the cell wall to anchor at the plasmic fracture face and in the cytoplasm to reach the ectoplasmic fracture face, and rarely penetrating the red membrane. The red membrane contained cylindrical or tubular particles in complementary freeze replicas. In the region of the purple membrane, in contrast, similar filaments or particles did not occur with comparable sharpness. The deep-etched filaments and freeze-fracture particles possibly represent a part of the transmembranous system connecting the biostatic cytoplasm with the ectoplasm or cell wall which is under continuous exposure to the extreme environment of brine.