Fig. 5: Logarithmic correlation of the substrate affinity (K_m(app)) and specific substrate affinity (a°) with the cellular surface area to volume ratio of ammonia-oxidizing microorganisms (AOM).

All K_m(app) (a, c) and a° (b, d) values correspond to values presented in Fig. 2. The surface area to volume (SA/V) ratio calculations for each AOM are provided in Table S4. Data for AOA (red), comammox (blue), and AOB (black) are shown. The three different gradations of red differentiate three distinct AOA phylogenetic lineages. The error bars represent the standard deviation of replicate kinetic experiments or SA/V ratio measurements of each AOM strain. The logarithmic correlation (R²) value was calculated from the average values of each AOM and is presented on a semi-log axis.