This website deals with how ammonia is released in an aquarium. Perhaps it is the presence of the intermediate amino acids that are utilised by other organisms:
http://www.thinkport.org/ad8a172c-5a94-484d-bd73-8b0884783e9c.asset
Ammonification
This process involves the degradation of proteins from dead plant and animal tissue and the release of ammonia into the environment. The process starts with the release of proteolytic enzymes from bacteria that hydrolyze proteins of plant and animal origin into amino acids. The amino acids are subsequently deaminated accompanied by the release of ammonia.
proteolysis
Plant! Animal protein -----------------polypeptides
deamination
amino acids------------------------ ammonia (NH3)
http://www.thinkport.org/ad8a172c-5a94-484d-bd73-8b0884783e9c.asset
Ammonification
This process involves the degradation of proteins from dead plant and animal tissue and the release of ammonia into the environment. The process starts with the release of proteolytic enzymes from bacteria that hydrolyze proteins of plant and animal origin into amino acids. The amino acids are subsequently deaminated accompanied by the release of ammonia.
proteolysis
Plant! Animal protein -----------------polypeptides
deamination
amino acids------------------------ ammonia (NH3)