An analysis on Soil Ammonia Oxidisers under different Nitrogen use Efficiency Strategies: Understanding the role of soil physiochemical properties in the activity of ammonia oxidizers

Abstract

The initial and rate-limiting step in nitrification is the oxidation of ammonia, which is carriedout by both ammonia-oxidizing archaea (AOA) and bacteria (AOB). Environmental factors that influencethe quantity, composition, and activity of AOA and AOB communities in soil nitrification are not fullydefined, and the relative importance of these two groups in nitrification is still up for debate. AOBpopulations were found to be rising, as predicted, but there was no discernible influence of JX soil onany other taxa studied. And moreover, stable-isotope DNA probing demonstrated that during activenitrification, AOA outcompeted bacteria by factors of 37.0-, 10.5-, and 1.91-fold in the ZY, JD, and LZsoils, 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 acetylenecompletely inhibited 13CO2 uptake by nitrifying populations. Molecular phylogenetics suggests thatAOA associated with soil fosmid 29i4 catalysed archaeal ammonia oxidation within the soil group 1.1bbranch. In the ZY, LZ, and JX soils, 13C-AOB belonging to the Nitrosomona communis lineage did thebulk of the ammonia oxidation, but in the JD soil, AOB similar to Nitrosospira cluster 3 did most of thework. The 13C-NOB was predominated by Nitrospira rather than Nitrobacter. Under microaerophilicconditions, 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 ammoniaoxidizer and nitrite oxidizer activities.