Robertkochia sediminum sp. nov., isolated from coastal sediment

An orange-pigmented, Gram-negative, strictly aerobic, non-flagellated, and rod-shaped bacterium, designated strain 1368T, was isolated from coastal sediment collected from Xiaoshi Island, Weihai, China. The optimal growth conditions were determined to be at 37 °C, pH 7.0 and in 2%–3% (w/v) NaCl. According to the phylogenetic analysis of the 16S rRNA gene sequence, strain 1368T showed the highest sequence similarity of 97.8% to Robertkochia marina JCM 18552T, followed by R. solimangrovi KCTC 72252T (96.5%). The DNA G + C content was 45.7% and the major fatty acids were iso-C15:0, iso-C15:1 G and iso-C17:0 3-OH. The major polar lipids were one phosphatidylethanolamine, two unidentified aminolipids and two unidentified lipids. The predominant respiratory quinone was menaquinone-6 (MK-6). The DNA–DNA relatedness between the genomes of strain 1368T and R. marina JCM 18552T and R. solimangrovi KCTC 72252T was 18.2% and 18.4%, and the average nucleotide identity were 70.6% and 73.8%, respectively. On the basis of the phenotypic, genetic and physiological characteristics, strain 1368T was suggested to represent a novel species of the genus Robertkochia, for which the name Robertkochia sediminum sp. nov. is proposed. The type strain is 1368T (MCCC 1H00444T = KCTC 82418T).