Ammonia oxidation by the enrichment culture "Candidatus Nitrosacidococcus tergens" sp. RJ19 across a pH gradient from pH 2.5 to 7.0
Acidophilic ammonia-oxidizing bacteria (AOB) have only recently been discovered. These organisms hold great promise for acidic wastewater treatment, yet their physiology remains poorly understood compared to neutrophilic AOB. Here, we investigated the physiology of the acidophilic AOB “Candidatus Nitrosacidococcus tergens” sp. RJ19 across a broad pH range (2.5–7.0) using a specialized bioreactor system. We monitored nitrogen (N) transformations combined with microbial community composition and transcriptomic profiles, focusing on nitrogen metabolism and proton stress responses.