Effect of nitrification inhibitors on ammonia oxidizers

Nitrification inhibitors 1-octyne and 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-oxide (PTIO) were frequently used as specific inhibitors for ammonia-oxidizing bacteria (AOB) and archaea (AOA), respectively, before complete ammonia oxidizer (comammox Nitrospira) were discovered. However, the influence of 1-octyne and PTIO on comammox Nitrospira remains largely elusive. Here, we investigated the effect of nitrification inhibitors, such as acetylene, 1-octyne and PTIO on ammonia oxidizers, especially the comammox Nitrospira, in an acidic Ultisols following 32-year fertilizations.