Microbacterium mitrae sp. nov., isolated from salted turban shell

Abstract

A novel bacterium (strain M4-8T) belonging to the genus Microbacterium was isolated from salted turban shell, which is a traditional fermented food in Korea. Its morphology, physiology, biochemical features and 16S rRNA gene sequence were characterized. Cells of this strain were Gram-positive, non-motile, non-spore-forming rods that formed yellow-pigmented colonies. It grew in 0–8 % (w/v) NaCl and at 15–37 °C, with optimal growth occurring in 1 % (w/v) NaCl and at 30 °C. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain M4-8T is associated with members of the genus Microbacterium. Within the phylogenetic tree, this novel strain shared a branching point with Microbacterium hominis IFO 15708T (97.8 % similarity). The DNA G+C content was 71.3 mol% and DNA–DNA hybridization experiments showed a low level (<29 %) of DNA–DNA relatedness between M4-8T and its closest relatives. The major fatty acids were iso-C15 : 0 and anteiso-C15 : 0 and the major cell-wall diamino acid was ornithine. Data obtained from DNA–DNA hybridization and chemotaxonomic phenotypic analysis support the conclusion that strain M4-8T represents a novel species within the genus Microbacterium. The name Microbacterium mitrae sp. nov. is proposed, with M4-8T (=KACC 21129T =JCM 16363T) as the type strain.