Changes of abundance and diversity of ammonia-oxidizing archaea (AOA) and bacteria (AOB) in three nitrifying bioreactors with different ammonia concentrations

Different from ammonia-oxidizing bacteria (AOB), the influence of ammonia levels on ammonia-oxidizing archaea (AOA) in wastewater treatment systems was poorly understood. In this study, sludge contained AOA and AOB was enriched in three sequencing batch reactors (named as R1, R2, and R3) under different ammonia levels (14, 56, and 140 mg/L) using polymerase chain reaction (PCR), cloning, sequencing, and quantitative real-time PCR (qPCR) to...