DEAMINIZATION 55 



Deaminization in the Lower Forms of Life. 



If we turn now to the lower forms of life we find that deaminiza- 

 tion is a normal function of both moulds and the micro-organisms of 

 putrefaction. Shibata (372) made a dry acetone preparation of As- 

 pergillus Niger and tested its deaminizing activity on various sub- 

 stances. It split off ammonia from urea, biuret, acetamide, asparagine 

 and alanine but did not decompose guanidine, allantoin and uric acid. 

 In the case of asparagine the yield of ammonia was small, and he con- 

 cluded on quite insufficient evidence that in this case the ammonia came 

 from the amino acid NH 2 group and not from the amide NH 2 group. 

 The deaminizing capabilities of bacteria have been investigated by 

 Brasch and Neuberg (74), Neuberg and others (303), Brasch (73), Bor- 

 chardt (69), whilst the action of yeast has been studied by Ehrlich (109). 

 Weinland (417) in an extremely interesting paper on the excretion of 

 ammonia by fly larvae gave excellent evidence in support of deaminiza- 

 tion. The Calliphora larvae are flesh eaters, and Weinland found that 

 in the course of larval development, when much flesh was eaten, am- 

 monia was given off in large amount. 



From all the evidence cited we may conclude that the process of 

 deaminization is a fundamental one in the metabolism of proteins, and 

 particularly of that portion of the protein which serves for dynamic 

 purposes. 



