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

Abstract

A novel bacterium (strain M4-8(T)) 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 M4-8(T) is associated with members of the genus Microbacterium. Within the phylogenetic tree, this novel strain shared a branching point with Microbacterium hominis IFO 15708(T) (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 M4-8(T) and its closest relatives. The major fatty acids were iso-C(15 : 0) and anteiso-C(15 : 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 M4-8(T) represents a novel species within the genus Microbacterium. The name Microbacterium mitrae sp. nov. is proposed, with M4-8(T) (=KACC 21129(T) =JCM 16363(T)) as the type strain.