The accumulation of formamide during the fermentation of histidine by Clostridium tetanomorphum.

A histidine fermenting Clostridium was isolated in this laboratory by Dr. Arthur Kornberg by standard enrichment culture techniques. This bacterium, which can use either L-histidine or i-glutamic acid as a primary energy source, has been identified as Clostridium tetanomorphum (Breed et al., 1948). Cell suspensions of the organism have been shown to form carbon dioxide, ammonia, hydrogen, formate, acetate, and butyrate from L-histidine. The accumulation of at least one additional nitrogenous product is indicated by the relatively low (67-80 per cent) recovery of the nitrogen of histidine as ammonia. This paper demonstrates that formamide is a product of histidine fermentation and shows that it originates from the carbon at position 2 and the 5-nitrogen of the imidazole ring.