Fig. 4

Denitrification Pathway. A Schematic representation of the denitrification pathway and the genes associated with each step. B The distribution of denitrification genes in the fourteen Castellaniella genomes. Non-ORR genomes are listed in black and ORR genomes are colored according to their matching ASV where purple represents ASV1 matching genomes, green represents the ASV2 matching genome and blue represents genomes which do not match either ASV. Genes shown include those encoding the nitrate/nitrite transporter (narK), the respiratory nitrate reductase and associated assembly proteins (narGHJI), the copper-containing respiratory nitrite reductase (nirK), the nitrite transporter (nirC), the NAD(P)H nitrite reductase (nirBD), the cytochrome c-dependent nitric oxide reductase (norBC), and the nitrous oxide reductase and associated assembly proteins (nosXLYFDZR)