Current insights into the autotrophic thaumarchaeal ammonia oxidation in acidic soils

► Acidic soils occupy approximately 30% of the world's ice-free lands. ► Ammonia oxidation mechanisms in acidic soil are not clear. ► AOA may play more important role in acid soil ammonia oxidation than AOB. ► Thaumarchaeal adaptation to low pH could attribute to low-pH-reduced ammonia availability.