Hydrogen-oxidizing methane bacteria. II. Electron microscopy.

Comparison of the fine structure of the methanogenic organism from the culture known as Methanobacillus omelianskii with that of Methanobacterium formicicum revealed a great similarity. Both organisms exhibited a large number of intracytoplasmic membranous elements when stained with phosphotungstic acid. In contrast, no such elements were observed in Methanobacterium ruminantium.