On the metabolism of an amino acid fermenting Clostridium.

Two anaerobic microorgaisms were isolated by the enrichment culture technique from a sodium formate-mineral salts medium inoculated with black mud from the San Francisco Bay. One of these, a motile coccus designated Methanococcus vannielii, carries out a methane fermentation of formate (Stadtman and Barker, 1951). The second organism that was almost equally numerous in the enrichment cultures is a clostridium that utilizes the Stickland reaction, a coupled oxido-reduction reaction between amino acid pairs. The addition of formate causes marked stimulation of growth of the clostridium under certain conditions. This observation suggested that the organism might be suitable biological material for studies on formate intermediary metabolism. Moreover, tracer experiments which are described in another communication showed that considerable amounts of formate carbon appear in alanine and the branched chain amino acids, valine, leucine, or isoleucine.