Methane formation; fermentation of ethanol in the absence of carbon dioxide by Methanobacillus omelianskii.

Stadtman and Barker (1949) using C14 labeled C02 demonstrated that the methane produced in this fermentation is formed entirely by reduction of C02. Experiments with growing cultures led to the conclusion (Barker, 1939, 1956) that the oxidation of alcohol is dependent upon the supply of carbon dioxide, and that when the carbon dioxide is consumed, no further oxidation of alcohol occurs. This paper presents evidence that washed suspensions of M. omelianskii are able to oxidize ethanol in the absence of carbon dioxide.