CHARACTERISTIC CELL WALL STRUCTURE OF A FUSOBACTERIUM

Abstract

The surface structure of a strain of Fusobacterium polymorphum was studied electron microscopically employing both carbon replica and ultrathin sectioning techniques. The surface of the cell wall as revealed by the carbon replica technique showed a succession of granular protuberances. In ultrathin sectioned preparations, the cell wall consisted of two layers. The first layer consisted of a three layered structure, simulating the appearance of an unit membrane, and waved rather sharply. The innermost edge of the second layer waved lightly, and tended to be adjacent to the tips of the infoldings of the first. The diameters of the granular protuberances in carbon replicas coincided, on the whole, with the wave periods of the first layer in ultrathin sections. The cytoplasmic membrane was recognized as an unit membrane and infolded into the interior of the cytoplasm at certain places. The intracytoplasmic membrane system which bore a connection with the cytoplasmic membrane and showed diverse profiles was also observable.