230 AGRICULTURAL AND INDUSTRIAL BACTERIOLOGY 



leaving the corresponding acid behind. The amino group 

 is thus converted into ammonia and the process from the 

 standpoint of the soil bacteriologists is frequently termed 

 ammonification. As an example of this change may be 

 given the transformation of glycocoll into acetic acid and 

 ammonia. The reaction may be written as follows : 



CH 3 NH 3 COOH + H 2 = CH 3 COOH + NH 3 

 Glycocoll Acetic acid Ammonia 



It will be noted that this transformation requires the 

 presence of nascent hydrogen. The change is one, therefore, 

 which is essentially anaerobic. Microorganisms which grow 

 in the presence of oxygen, that is, under aerobic conditions, 

 may in some cases bring about deaminization by oxidation. 

 In this case a fatty acid containing one less carbon atom in 

 the chain is usually formed. The reaction may be indicated 

 as follows: 



CH 3 CHNH ? COOH + 2 = CH 2 COOH + NH 3 + C0 2 

 Alanin Acetic Acid 



It is evident, therefore, that either under aerobic or ana- 

 erobic conditions microorganisms may free ammonia from 

 amino acids. This is important, because ammonia may be 

 utilized directly, or after conversion into nitrates, by 

 higher plants as nutrient material. 



Certain microorganisms when growing under anaerobic 

 conditions may attack amino acids eliminating carbon 

 dioxide, thereby changing the compound from an amino 

 acid to an amine. This process is termed decarboxlyation. 

 It may be illustrated by the following reaction : 



CH 3 CHNH 2 COOH = CH 3 CH 2 NH 2 + C0 2 

 Alanin Ethylamine 



Amines produced as a result of the action of microorgan- 

 isms are frequently termed ptomaines. Some of the amines 



