FERMENTATIONS OF NITROGENOUS COMPOUNDS 79 



blue, suggested that the oxidation of glycine was coupled 

 with the reduction of urate. Evidence was also obtained 

 that the decomposition of uric acid under some conditions 

 was dependent on the presence of glycine. Certain thor- 

 oughly washed and aged cell suspensions of CI. acidi-urici 

 could ferment uric acid only after a long lag period. The 

 lag could be abolished completely by the addition of 

 glycine. 54 



Further investigation of the role of glycine in the purine 

 fermentation was delayed for several years. During this 

 interval, Sonne, Buchanan, and Delluva 55 studied the syn- 

 thesis of uric acid in the pigeon and established by means 

 of tracer experiments with C 14 that various carbon atoms 

 in the purine are derived from carbon dioxide, formate, 

 and glycine. Uric acid carbon atoms 2 and 8 are derived 

 from formate, carbon atoms 4 and 5 from the carboxyl and 

 methylene groups of glycine respectively, 56 and carbon atom 



6 from carbon dioxide (Fig. 4) . The nitrogen in position 



'NH— 6 C0^— C0 2 



HCOOH — ^ 2 C0 pC— -NH! 8 



3 1 iJL /CO <— HCOOH 



3 NH-t 4 C^- 9 NH 



T 



CH 2 — NH 2 

 I 

 COOH 



Fig. 4. Uric Acid Synthesis in Pigeons. 



7 was shown also to be derived from glycine. 57 Therefore 

 glycine appeared to be incorporated intact into the adjacent 

 positions 4, 5, and 7 of the purine^ 



In view of the obvious similarities between the bacterial 

 purine fermentations and purine synthesis in the pigeon, 

 it seemed probable that the two processes would follow the 

 same general pathway but in opposite directions, particu- 



