Table 1.

Characteristics of the ‘model’ AOA (N. maritimus) and AOB (N. europaea), six AOA soil isolates or enrichments and a range of soil AOB. Some data are not available for certain strains and cell yield and activity data for Nitrosotalea strains are not directly comparable when presented in terms of NH₃. Cell yield and specific cell activity of C13 calculated using cell and amoA gene concentrations are labelled ^a and ^b, respectively.

			Cell yield	Specific cell activity	Inhibitory	Inhibitory
Organism	Size (μm)	μ max (h−1)	(cells μM−1 NH3)	(fmol NO2− cell−1 h−1)	NH4+ conc. (mM)	HNO2 conc. (μM)	References
Nitrosopumilus maritimus SCM1	0.17–0.22 × 0.5–0.9	0.033	5 × 104	0.53	2	0.028	Könneke et al. (2005)
Nitrososphaera viennensis EN76	0.6–0.8 diam	0.024			20	0.79	Stieglmeier et al. (2014a)
Nitrosoarchaeum koreensis MY1	0.3–0.5 × 0.6 – 1.0		1.1 × 105	2.5	20	0.50	Jung et al. (2011)
Nitrosotenuis chungbukensis MY2	0.2 × 0.7		3.4 × 105		20	0.50	Jung et al. (2014)
Nitrosotalea devanaterra Nd1	0.33 × 0.89	0.011	4.5 × 105	0.072	50	0.91–3.5	Lehtovirta-Morley et al. (2011)
Nitrosotalea sp. Nd2	0.2 × 0.7	0.025	4 × 105	0.065		1.61–5.7	Lehtovirta-Morley et al. (2014)
Nitrosocosmicus franklandus (C13)	1.1 diam	0.024	a7.60 × 103/ b1.29 × 105	a2.02 b0.58	>100 mM	1.58	This study
Nitrosomonas europaea ATCC 19718	0.8–1.1 × 1.0–1.7	0.052–0.066	4.61–6.44 × 103	11	>400	31.6	Prosser (1989); Hunik, Meijer and Tramper (1992); Koops et al. (2006)
Soil AOB (data collated from approximately 25 strains)	0.3–0.8 × 1.0–8.0	0.005–0.044	1.38–10.6 × 103	4–23	7–50		Prosser (1989); Koops and Pommerening-Röser (2001); Koper et al. (2010); Prosser and Nicol (2012)