206 AMMONIFICATION 



The quantity and quality of the products formed would depend 

 upon the specific enzyme or enzymes secreted by the microorgan- 

 isms. Where pepsin is the main ferment large quantities of proteoses 

 and peptones would be formed, while if trypsin is the active agent 

 the amino-acids would also occur, and with erepsin the amino-acids 

 would be formed even more rapidly. It is not unreasonable to 

 suppose that in a soil having a high ammonifying efficiency the 

 ammonifying flora are not only numerous but they are active 

 secreters of proteoclastic ferments. Moreover, this disintegration 

 of the protein molecule which eventually converts nearly the whole 

 of the organic nitrogen into ammonia results from the combined 

 action of numerous microorganisms of different species. The 

 products elaborated by one class probably serve as the point of 

 attack for another. 



Potter and Snyder found there was no tendency for the amino- 

 acids to accumulate in the soil, but they fluctuated with the ammonia, 

 thus indicating a connection between the two. Jodidi added 

 various amino-acids and acid amids, including glycocol, leucin, 

 phenylalanin, asparagin, aspartic acid, glutanic acid, tyrosin, 

 alanin, cadaverin, acetimid and propionamid to the soil, and after 

 from two to ten days determined the ammonia, although the 

 transformation was not quantitative, probably due to other reac- 

 tions occurring simultaneously. Yet it was evident that the 

 amino-acids and acid amids examined readily undergo in the soil 

 the proc'ess of ammonification, and, all other things being equal, the 

 rate of transformation is greatly influenced by the chemical struct- 

 ure so that amino-acids and acid amids of equal structure yield 

 about the same proportion of ammonia. 



Effront in 1905 demonstrated that there are produced by soil 

 bacteria amidases. The process of deamination was at first 

 thought to be one of simple hydrolysis, as follows: 



R CH NH 2 COOH + HOH R CHOH COOH + NH 3 



But Neubauer and Fromberz concluded that the primary pathway 

 of deamination within the animal organism was oxidative and not 

 hydrolytic: 



R R R 



| H | OH 



2C/ + 2 = 2C/ = 2C = O + 2NH 3 



\NH 2 |\NH, 



COOH COOH COOH 



Ammo-acid Oxy-amino-acid Keto-acids 



The amino-acids containing sulphur would probably in the 

 presence of sufficient oxygen first oxidize the sulphur atom forming a 

 derivative of sulphuric acid : 



CH 2 SH 



2CH NH 2 + 3O 2 = 2CH NHj 



I I 



COOH COOP 



