Fig. 2: Phylogeny and distinctive metabolic traits of Nitrososphaerales.

This tree includes 26 Nitrososphaerales genomes and was inferred by maximum likelihood reconstruction from 188 concatenated marker genes. The 12 new genomes obtained in this study are indicated by red tip labels and the tree is rooted with the Ca. Nitrosocaldales strains 3F and SCU2. This tree has similar topology to the phylum-wide tree, but with strong support for almost all branches. Dots indicate branches with >95% UFBoot and SH-aLRT support. Colours on branches and leaf labels indicate families and genera, respectively. While many of the genes acquired in early stages of Nitrososphaerales evolution are uncharacterised, several genes involved in molybdoenzymes synthesis and stress response could be identified, among which several are represented on the figure. The presence and absence of those genes are indicated by a filled or empty circle, respectively. The following genes were used in the figure: wtpABC, Wtp transport system subunits A, B and C; MOSC, molybdenum cofactor sulfurase; MoOR, Molybdopterin oxidoreductase; wrbA, NAD(P)H quinone oxidoreductase; poxB, pyruvate oxidase; GSR, glutathione-disulfide reductase; kdpABC, potassium transport system subunits A, B and C; M3PSA, mannosyl-3-phosphoglycerate synthase; M3PP, mannosyl-3-phosphoglycerate phosphatase; CE, carbohydrate esterase family; GH, glycoside hydrolase family. Closest BLASTn⁶² matches in the Alves², Gubry-Rangin¹⁴ and Vico-Oton²¹ databases are indicated for the Nitrososphaerales genomes on the right of the figure. Genomes in which amoA or 16S rRNA genes were not detected are indicated with a hyphen (-).