An analysis on Soil Ammonia Oxidisers under different Nitrogen use Efficiency Strategies | Original Article

ABSTRACT:

The initial and rate-limiting step in nitrification is the oxidation of ammonia, which is carried out by both ammonia-oxidizing archaea (AOA) and bacteria (AOB). Environmental factors that influence the quantity, composition, and activity of AOA and AOB communities in soil nitrification are not fully defined, and the relative importance of these two groups in nitrification is still up for debate. AOB populations were found to be rising, as predicted, but there was no discernible influence of JX soil on any other taxa studied. And moreover, stable-isotope DNA probing demonstrated that during active nitrification, AOA outcompeted bacteria by factors of 37.0-, 10.5-, and 1.91-fold in the ZY, JD, and LZ soils, respectively, whereas in the JX soil, AOB but not AOA were tagged. Nitrogen-oxidizing bacteria (NOB) were discovered in greater numbers than nitrogen-fixing bacteria (AOA and AOB), and acetylene completely inhibited 13CO2 uptake by nitrifying populations. Molecular phylogenetics suggests that AOA associated with soil fosmid 29i4 catalysed archaeal ammonia oxidation within the soil group 1.1b branch. In the ZY, LZ, and JX soils, 13C-AOB belonging to the Nitrosomona communis lineage did the bulk of the ammonia oxidation, but in the JD soil, AOB similar to Nitrosospira cluster 3 did most of the work. The 13C-NOB was predominated by Nitrospira rather than Nitrobacter. Under microaerophilic conditions, the relative activity of AOA and AOB indicates that AOA is more advantageous than AOB. According to these results, soil physiochemical properties have a crucial role in determining ammonia oxidizer and nitrite oxidizer activities.