Bacterial_amoA
15 g of soil was mixed with 100 mL of 0.75 mM ammonium sulfate, which was adjusted to pH 7.2, and was incubated at room temperature. Then, DNA was extracted from 15 mL of slurry taken an hour after the incubation had started. The region of bacterial amoA (primers: amoA-1Fmod and GenAOBR; as described in Meinhardt et al., 2015) was amplified using PCR and sequenced with Ion PGM