A PHYLOGENETIC ANALYSIS OF THE GENUS BLASTOBACTER WITH A VIEW TO ITS FUTURE RECLASSIFICATION

Near complete 16S rRNA gene sequences were determined for three culturable species of the genus Blastobacter; B. aggregatus, B. capsulatus and B. natatorius and compared to the homologous sequences of Blastobacter denitrificans and related members of the alpha subclass of the class Proteobacteria. A phylogenetic analysis of the sequence data demonstrated that B. aggregatus and B. capsulatus possessed high sequence similarity to each other and to Agrobacterium tumefaciens (alpha-2 group of the alpha subclass), that B. natatorius was most closely related to Caulobacter subvibrioides, Porphyrobacter neustonensis and Erythrobacter longus (alpha-4 group) and that B. denitrificans groups with Bradyrhizobium japonicum and Rhodopseudomonas palustris (alpha-2 group in a branch distinct from B. aggregatus and B. capsulatus). Thus the genus Blastobacter is highly heterogeneous and its taxonomy should be revised.