Microbacterium natoriense sp. nov., a novel D-aminoacylase-producing bacterium isolated from soil in Natori, Japan

A rod-shaped Gram-positive bacterium, strain TNJL143-2^T having N-acyl-D-amino acid amidohydrolase (D-aminoacylase) activity, was isolated from a soil sample from Natori, Japan. It was a non-spore-forming, strictly aerobic bacterium without motility, showing a temperature optimum for growth of 30 °C and a pH optimum for growth of 5-7. The 16S rRNA gene sequence of the strain showed the highest similarities to members of the genus Microbacterium, in particular, Microbacterium aerolatum, Microbacterium foliorum and Microbacterium phyllosphaerae. The chemotaxonomic characteristics, including the compositions of cellular menaquinones, cellular fatty acids and cell-wall amino acids, were consistent with those described for the genus Microbacterium. The G+C content of the genomic DNA was determined as 69.1 mol%. DNA-DNA hybridization studies using type strains of M. aerolatum, M. foliorum and M. phyllosphaerae showed only low levels of relatedness (11-12%). On the basis of these phenotypic and genotypic results, a novel species, Microbacterium natoriense sp. nov., is proposed, with TNJL143-2^T (=JCM 12611^T=ATCC BAA-1032^T) as the type strain.