Formation of Methane by Bacterial Extracts.

The oxidation of ethanol to acetate by cultures of Methunobacillus omelianskii was found by Barker to be dependent upon carbon dioxide (1) ; using C140Z, Stadtman and Barker demonstrated conclusively that carbon dioxide was the precursor of methane (2). Recently Johns and Barker have reported hydrogen formation from ethanol by resting cells of M. omelianskii in the absence of carbon dioxide (3). The mechanism of carbon dioxide reduction to methane by M. omelianslcii as well as the mechanism of methane formation by other organisms is unknown. Current knowledge of the nutrition and fermentative patterns of the methane bacteria has been reviewed by Barker (4). The present communication is concerned with the formation of methane by cell-free extracts of &!f. omeliunskii; a brief report of some of these findings has appeared (5).