sp. nov., isolated from surface seawater of the Weddell Sea in Antarctica.

The poles of the Earth harbour many novel micro-organisms that have not yet been isolated and identified. Here, a Gram-stain-negative, motile, aerobic and rod-shaped bacterial strain, designated as wDCs-4, was isolated from surface seawater collected from the Weddell Sea in Antarctica. It grows at 4-40 °C (optimum 10-15 °C), pH 4-8 (optimum 7) and in the presence of 0-4% NaCl (w/v, optimum 0.5-1%). The complete 16S rRNA gene of strain wDCs-4 had maximum sequence identity with SM2-42 (97.2%), followed by MIL-1 (96.5%) and 197 (96.2%). Phylogenetic analyses based on the 16S rRNA gene and genome sequences showed that strain wDCs-4 was closely clustered with the members of the genus and formed an independent clade, which could be considered a monophyletic taxon. The average nucleotide identity values between strain wDCs-4 and the members of the genera and were 77.7-78.1 and 77.4-80.5%, respectively. The corresponding digital DNA‒DNA hybridization values are 19.5-20.1 and 20.5-22.4%, respectively. The major fatty acids (>5%) of strain wDCs-4 comprised summed feature 5 (C ante/C ,9 or C ,9/C ante) and C. The predominant respiratory was Q-8. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, aminolipids and unknown polar lipids. The draft genome size was 4.58 Mbp, with a DNA G+C content of 53.4 mol%. On the basis of polyphasic analyses, strain wDCs-4 represented a novel species in the genus , for which the name sp. nov. was proposed. The type strain was wDCs-4 (=MCCC 1A20726=KCTC 8314).