Robertkochia sediminum sp. nov., isolated from coastal sediment

An orange-pigmented, Gram-negative, strictly aerobic, non-flagellated, and rod-shaped bacterium, designated strain 1368(T), was isolated from coastal sediment collected from Xiaoshi Island, Weihai, China. The optimal growth conditions were determined to be at 37 degrees C, pH 7.0 and in 2%-3% (w/v) NaCl. According to the phylogenetic analysis of the 16S rRNA gene sequence, strain 1368(T) showed the highest sequence similarity of 97.8% to Robertkochia marina JCM 18552(T), followed by R. solimangrovi KCTC 72252(T) (96.5%). The DNA G + C content was 45.7% and the major fatty acids were iso-C-15:0, iso-C-15:1 G and iso-C-17:0 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 1368(T) and R. marina JCM 18552(T) and R. solimangrovi KCTC 72252(T) 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 1368(T) 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 1368(T) (MCCC 1H00444(T) = KCTC 82418(T)).