English

Abstract

Ammonia-oxidizing archaea (AOA) are one of the main regulators of ammoxidation, which is the primary rate-limiting step of nitrification. However, the biofertilizers’ effects on soil AOA are not presently well-understood. Therefore, soil samples treated with three biofertilizers viz., nitrogen-fixing bacterium, phosphate-solubilizing bacterium and Piriformospora indica, both individually and mixed (MI) were collected, in order to explore the variation in the AOA composition and diversity using high-throughput sequencing. The results revealed that the available nitrogen content in soil treated with nitrogen-fixing bacterium and MI were significantly higher than that in soil treated with sterile water. In addition, the MI treatment significantly increased the diversity of AOA in soil. The composition of AOA was not different among the treatments at phylum, class, order, or family level. However, this was somewhat different at the genus and species level. Nitrososphaera was dominant at the genus level among the different soil samples. The structural similarity of AOA communities was higher in the three soil samples treated with Piriformospora indica, phosphate-solubilizing bacterium and sterile water, while the communities in soil treated with nitrogen-fixing bacterium and the mixture of nitrogen-fixing bacterium (MI) were different from that in sterile water. The partial least squares discriminant analysis revealed that the classification models for P. indica, sterile water and phosphate-solubilizing bacterium performed well. The correlation network analysis demonstrated that there was a positive correlation between Candidatus, Nitrosotalea and Nitrosopumilus. The phylogenetic analysis of the AOA community revealed that ammonia-oxidizing archaea mostly belonged to Thaumarchaeota, followed by Crenarchaeota. In addition, there were some unknown archaea. © 2021 Friends Science Publishers