[Several cytologic features of the thermophilic bacteria Thermus flavus and Thermus ruber].

The extreme thermophilic bacterium Thermus flavus 71 and the obligate thermophilic bacterium Thermus ruber 40 have been isolated from hot springs of Kamchatka and Tadjikistan, and their fine structure has been studied. This cells are similar in structure to gram-negative bacteria, they do not form spores or flagella, and their cell walls and cytoplasmic membrane are clearly visible under the electron microscope since the cells of T . flavus contain a yellow carotenoid pigment and the cells of T. rubber contain a bright-red carotenoid pigment. The Thermus genus is characterized by a wavy structure of the outer layer of the cell wall caused by numerous invaginations which ensure a close contact between the outer and inner layers of the cell wall.