Union of the genera Microbacterium Orla- Jensen and Aureobacterium Collins et a/. in a redefined genus Microbacterium

The 165 rRNA gene sequences of 19 strains, 11 strains representing validated Aureobacterium or Microbacterium species and eight strains of non-valid species or isolates, were determined. These sequences were aligned with the sequences of other validated Aureobacterium and Microbacterium species and related actinobacteria. A comparative sequence analysis of 43 strains revealed that the species of the genera Aureobacterium and Microbacterium form a monophyletic association in which species of both genera are intermixed. The high similarity in phylogenetic properties found in the species within both genera and the close relationship in physiological and chemotaxonomic features other than the diamino acid in the cell wall, provided strong evidence that the genera Aureobacterium and Microbacterium should be unified. An emended genus Microbacterium is proposed for the two combined genera.