Microbacterium profundi sp. nov., isolated from deep-sea sediment of polymetallic nodule environments

A Gram-positive, aerobic, neutrophilic and rod-shaped bacterium, strain Shh49^T, was isolated from a deep-sea sediment sample collected from the East Pacific polymetallic nodule region. The strain was able to grow within a temperature range of 4-35 °C and tolerated up to 7.5% (w/v) NaCl. Strain Shh49^T was characterized chemotaxonomically by having MK-12 and MK-13 as predominant isoprenoid quinones, anteiso-C_15:0, iso-C_15:0, iso-C_16:0 and anteiso-C_17:0 as major fatty acids and ornithine as cell-wall diamino acid. The genomic DNA G+C content was 66.8 mol%. On the basis of 16S rRNA gene sequence similarities, the closest phylogenetic neighbours were the type strains of Microbacterium phyllosphaerae (98.3%) and Microbacterium keratanolyticum (98.0%), but strain Shh49^T could be clearly distinguished from its phylogenetic relatives with reference to a broad range of physiological and biochemical markers. DNA-DNA relatedness of strain Shh49^T with M. phyllosphaerae DSM 13468^T and M. keratanolyticum DSM 8606^T was 56 and 31%, respectively. On the basis of phenotypic and genotypic data presented in this study, strain Shh49^T represents a novel species of the genus Microbacterium, for which the name Microbacterium profundi sp. nov. is proposed. The type strain is Shh49^T (=CGMCC 1.6777^T =JCM 14840^T).