[Cytological characteristics of the thermophilic bacterium Thermus ruber]

The obligate thermophilic bacterium Thermus ruber 12b was examined using optical and electron microscopy. Its cells were shown to be polymorphous. In a liquid medium, the cells associate yielding complex spherical bodies having a surface layer in common and complexes consisting of two or more cells but without a common envelope. A large nucleoid is located in the central part of the cells; it contains polyphosphate granules. Fat inclusions and analogues of mitochondria with dehydrogenase activity typical of them can be detected at the periphery. The cell wall consists of a folded outer membrane, an underlying fibrillar material, and a thin rigid layer. Peculiar adhesion zones appear between the outer membrane and the rigid layer in places where folds are formed. An electron-dense substance is deposited on the surface of the three-layer cytoplasmic membrane.