Description of Brachybacterium sillae sp. nov., a thermophilic bacterium isolated from a hot spring.

The taxonomic position of strain EF45031 T , isolated from the Neungam Carbonate hot spring, was examined using the polyphasic taxonomic approach. Strain EF45031 T shared the highest percentage of 16S rRNA gene sequence with Brachybacterium nesterenkovii CIP 104813  T (97.7%). The average nucleotide identity (ANI), average amino acid identity (AAI), and digital DNA-DNA hybridization (dDDH) values between strain EF45031 T and the type strains B. nesterenkovii CIP 104813  T and B. phenoliresistens Phenol-A T were 77.0%, 69.15%, 21.9% and 75.73%, 68.81%, 20.5%, respectively. Phylogenomic analysis using an up-to-date bacterial core gene (UBCG) set revealed that strain EF45031 T belonged to the genus Brachybacterium. Growth occurred between 25 and 50 ℃ at pH 6.0-9.0 and could tolerate salinity up to 5% (w/v). Strain had anteiso-C 15:0 and anteiso-C 17:0 as major fatty acids. Menaquinone-7 (MK-7) was the predominant respiratory menaquinone. The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, three aminolipids, and two unidentified glycolipids. The cell-wall peptidoglycan contained meso-diaminopimelic acid as a diagnostic diamino acid. The genome comprised 2,663,796 bp, with a G + C content of 70.9%. Stress-responsive periplasmic chaperone/protease coding genes were identified in the genome of EF45031 T and were not detected in other Brachybacterium species. The polyphasic taxonomic properties indicate that the strain represents a novel species within the genus Brachybacterium, for which the name Brachybacterium sillae sp. nov. is proposed. The type strain is EF45031 T (= KCTC 49702  T  = NBRC 115869  T ).