Ammonification

The ammonification is part of the process of the nitrogen cycle and degradation of organic substances in ecosystems . Here, the nitrogen is released from nitrogen-containing organic substances through microbial processes in the form of ammonia (NH ₃ ).

Many destructors ( bacteria , archaea and fungi ) are able to split ammonia from organic nitrogen compounds. For example, ammonia can be split off from amino acids contained in proteins by deamination ; also amino sugars are deaminated. In addition, ammonia can be formed by hydrolysis of urea . In this reaction, urea (CO (NH ₂ ) ₂ ) is converted into ammonia (NH ₃ ) and carbon dioxide (CO ₂ ) by the enzyme urease :

${\displaystyle \mathrm {H_{2}N{-}CO{-}NH_{2}\ +\ H_{2}O\rightarrow 2\ NH_{3}\ +\ CO_{2}} }$

Ammonium ions are formed from ammonia dissolved in water . Since this creates hydroxide ions , the resulting solution is alkaline. The ratio of ammonia to ammonium ions depends on the pH value:

${\displaystyle \mathrm {NH_{3}\ +\ H_{2}O\ \rightleftharpoons \ NH_{4}^{+}\ +\ OH^{-}} }$

Ammonification causes the environment to become alkaline.

See also: nitrification , denitrification , transport (biology) , deamination

literature

• J. Simon: Enzymology and bioenergetics of respiratory nitrite ammonification. In: FEMS microbiology reviews. Volume 26, Number 3, August 2002, pp. 285-309, ISSN  0168-6445 . PMID 12165429 .

Individual evidence

1. ^ MG Klotz, LY Stein: Nitrifier genomics and evolution of the nitrogen cycle. In: FEMS microbiology letters. Volume 278, Number 2, January 2008, pp. 146-156, ISSN  0378-1097 . doi : 10.1111 / j.1574-6968.2007.00970.x . PMID 18031536 .
2. ^ DWA Bayern: Operation of sewage systems; The nitrogen balance in municipal wastewater. November 2011, accessed March 2, 2020 .