FERMENTATIONS OF NITROGENOUS COMPOUNDS 75 



to butyrate whereas 2 moles of threonine are oxidized to 

 propionate and carbon dioxide. The specific reactions in- 



3CH 3 CHOHCHNH 2 COOH + 2H 2 — *- 



CH3CH2CH2COOH + 2CH3CH2COOH 



+ 2C0 2 + 3NH 3 (9) 



volved in tllese processes have not been investigated but 

 it is probable that a-ketobutyrate is an intermediate in the 

 fermentation. 



AHantoin Fermentation by Streptococcus allantoicus. 



The decomposition of allantoin by S. allantoicus cannot be 

 represented by a simple equation. The major products are 

 ammonia, urea, oxamic acid, and carbon dioxide, and the 

 minor products are formic, acetic, lactic, and glycolic acids. 12 

 Oxamic acid, the monoamide of oxalic acid, has not been 

 found in any other fermentation. 



The chemistry of the allantoin fermentation has not been 

 extensively studied. The first step is known to be the open- 

 ing of the ring with the formation of allantoic acid. Beyond 

 this little is known with certainty except that the nitrogen 



NH 2 CO— NH 



/ 

 CO 



CO + h 2 o 



NH CH— NH 



Allantoin 



NH 2 COOH NH 2 



CO 



CO (10) 



NH CH NH 



Allantoic acid 



of oxamic acid is not derived from ammonia. This has 

 been shown by experiments with N 15 ammonia. Since 

 ammonia is formed in the fermentation and the organism 



