Micromorphology of Gram-negative hydrogen bacteria. II. Cell envelope, membranes, and cytoplasmic inclusions.

The fine structure of the cell envelope, of membrane systems and of cytoplasmic inclusions of Gram-negative aerobic hydrogen bacteria has been studied. The results have been tabulated, and three main groups could be recognized: Group 1: Alcaligenes eutrophus, A.paradoxus, A.ruhlandii, Pseudomonas facilis, P.flava, P.pseudoflava, P.palleronii, and Aquaspirillum autotrophicum; Group 2: "Corynebacterium" autotrophicum and strains MA 2 and SA 35; Group 3: Paracoccus denitrificans. Special structures related to the chemoautotrophic way of life of the hydrogen bacteria were not observed.