Brachybacterium horti sp. nov., isolated from garden soil

A bacterial strain, THG-S15-4T, was isolated from garden soil taken from the Guro-gu district of Seoul, Republic of Korea. Strain THG-S15-4T was Gram-stain-positive, facultatively anaerobic, coccus-shaped and non-motile, forming white colonies. The strain grew optimally at 25-37 °C, at pH 7.0 and in the presence of 0-2.0 % (w/v) NaCl. Phylogenetic analysis, based on 16S rRNA gene sequences, showed that strain THG-S15-4T was affiliated to species of the genus Brachybacterium, and the most closely related species were Brachybacterium rhamnosum KCTC 9917 T (98.5 % sequence similarity) and Brachybacterium squillarum KCTC 19899T (96.9 % sequence similarity). The DNA-DNA relatedness between strain THG-S15-4T and B. rhamnosum KCTC 9917 T was found to be below 20.0 %. The DNA G+C content was determined to be 69.5 mol%. The major isoprenoid quinone detected was MK-7. Strain THG-S15-4T was characterized chemotaxonomically as having meso-diaminopimelic acid in the cell-wall peptidoglycan. The polar lipid profile consisted of diphosphatidylglycerol, phosphatidylglycerol, unidentified glycolipids and an unidentified polar lipid. The major fatty acids were found to be iso-C16 : 0 and anteiso-C15 : 0. The results of physiological and biochemical tests enabled strain THG-S15-4T to be differentiated phenotypically from species of the genus Brachybacterium with validly published names. Therefore, it is suggested that this newly isolated organism represents a novel species, for which the name Brachybacterium horti sp. nov. is proposed. The type strain is THG-S15-4T ( = KCTC 39563T = CCTCC AB 2015116T).