Phylogenetic tree on the basis of 16 S rRNA genes for O. carboxidovorans OM5, B. japonicum USDA110, Nitrobacter hamburgensis X14, and Bradyrhizobium sp. BTAi1 where Arthrobacter was used as outgroup. The tree was created using Treecon. Bootstrapping is shown for values 70% and above. The tree is based on distance matrix where 0.1 means 10% difference between two sequences.