The study by Wolin, Wolin, and Wolfe investigates the formation of methane by cell-free extracts of *Methanobacillus omelianskii*. The researchers found that methane production was dependent on the presence of hydrogen, carbon dioxide, coenzyme A (CoA), and adenosine triphosphate (ATP). Pyruvate, serine, or O-phosphoserine could substitute for ATP and carbon dioxide. A hydrogen atmosphere was essential for optimal methane formation. The extracts were sensitive to oxygen, and their activity varied with the condition of the cells at the time of preparation. Ferredoxin stimulated methane production when added to reactions containing pyruvate, but its role was not fully elucidated. The study also noted that ethanol, despite being a substrate for growth, was ineffective in methane formation when added to extracts. The findings provide insights into the biochemical mechanisms of methane formation by *M. omelianskii*.The study by Wolin, Wolin, and Wolfe investigates the formation of methane by cell-free extracts of *Methanobacillus omelianskii*. The researchers found that methane production was dependent on the presence of hydrogen, carbon dioxide, coenzyme A (CoA), and adenosine triphosphate (ATP). Pyruvate, serine, or O-phosphoserine could substitute for ATP and carbon dioxide. A hydrogen atmosphere was essential for optimal methane formation. The extracts were sensitive to oxygen, and their activity varied with the condition of the cells at the time of preparation. Ferredoxin stimulated methane production when added to reactions containing pyruvate, but its role was not fully elucidated. The study also noted that ethanol, despite being a substrate for growth, was ineffective in methane formation when added to extracts. The findings provide insights into the biochemical mechanisms of methane formation by *M. omelianskii*.