Heterotrophic nitrification – An eternal mystery in the nitrogen cycle

• DOI: 10.1016/j.soilbio.2022.108611
• Publication Date: 2022-03-15T10:30:01Z
• Authors: Pertti J. Martika...
• Keywords: Ammonia monooxygenase; Nitrogen Cycle

Despite the fact that heterotrophic nitrification was identified more than 100 years ago, biochemistry of nitrifiers is poorly known and their contribution to in soil still speculative. Heterotrophic need organic compounds as energy source contrast chemolithotrophic nitrifiers. Most potential pathways for nitrite/nitrate production by heterotrophs can be considered secondary metabolism. Only simultaneous denitrification some bacteria have connection Evidently, fungi differ. Some oxidizing ammonia monooxygenase (AMO), but there are also without AMO. The structure AMO oxidizers differs. has not been found nitrifying fungi. conditions highly differ from those waste waters where activity high. limited low availability easily decomposable substrates. Possible rhizosphere endophytic root microbes gaining a good supply substrates plants known. Fungi special interest because evidently nitrify only when decomposing recalcitrant (like lignin) which abundant soil. Nitrite/nitrate nitrogenous compounds, such amino acids, common among general conclusion use solely an "organic pathway" is, however, valid oxidized. Owing diverse, methodological difficulties differentiate soil, role nitrogen cycle remains uncertain.