Ammonification,Protein,Amines,Amides,Urea,Nucleic Acids,Bacteria,Fungi,Actinomycetes,Organic Nitrogen,Polypeptides,Aminoacids,Pseudomonas

Ammonification

	Ammonification It is an important step in the nitrogen cycle that helps in the mineralisation of bound nitrogen (organic). This is performed by a large number of organisms present in the soil that playa role in decomposition. Ammonification is thus the mineralisation of bound organic nitrogen into inorganic ammonia.
Sources of Nitrogen for Ammonification 1. Protein 2. Amines 3. Amides 4. Urea 5. Nucleic acid (bases) A number of bacteria, fungi and actinomycetes attack the organic nitrogen at varying rates of decomposition. As a first step, the fungi attack the proteins breaking them down to polypeptides. Then the bacteria act on the polypeptides and convert them to aminoacids which are then cleaved to release ammonia. Proteins→ → → Polypeptides → → Aminoacids
The bacteria that help in ammonification include Pseudomonas, Bacillus, Clostridium and Serratia, while the fungi genera include Alternaria, Mucor, Aspergillus and Penicillium. Microbes synthesise extracellular proteolytic enzymes for protein decomposition. Major end products of aerobic proteolysis are carbon dioxide, ammonia, sulphates and water. Anaerobic decomposition of proteins (putrefaction) releases foul- smelling compounds like H2S, mercaptans, etc.
Fungi release less ammonia than bacteria since they assimilate more of the nitrogen for cellular synthesis (since fungi have a greater cellular mass). The other substrates for ammonia release include: Urea Enzyme involved is urease, e.g. Bacillus, Proteus, Micrococcus, Sarcina, etc. Amines Substrates are ethylamine, methylamine using the enzyme amino-oxidases produced by Mycobacterium, Pseudomonas, Protoaminobacter.
	Amides Chlorella, a green alga utilises amides for producing ammonia. It has the enzyme amidase. Nucleic acids The attack is initiated by ribonuclease and deoxyribonuclease.

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Ammonification