Sphingomicrobium arenosum sp. nov., isolated from marine sediment.

A Gram-stain-negative, strictly aerobic, motile by one single flagellum, dark-orange pigmented and rod-shaped bacterial strain, designated CAU 1457, was isolated from marine sediment in the Republic of Korea and its taxonomic position was investigated by using a polyphasic approach. The isolate grew optimally at 30 °C, at pH 6.0 and in the presence of 2 % (w/v) NaCl. Based on 16S rRNA gene sequences similarity, strain CAU 1457 belonged to the genus Sphingomicrobium and was related most closely to Sphingomicrobium astaxanthinifaciens JCM 18551 (98.2 % similarity). Strain CAU 1457 contained ubiquinone-10 as the predominant isoprenoid quinone and 11-methyl C18 : 1ω7c and summed feature 8 (C18 : 1ω7c/ω6c) as the major cellular fatty acids. Triamine sym-homospermidine was detected as the major compound in the polyamine pattern. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, four unidentified glycolipids, one unidentified aminophospholipid, two unidentified phospholipids, one unidentified aminolipid and one unidentified lipid. DNA-DNA relatedness between strain CAU 1457 and the closely related strains, Sphingomicrobium astaxanthinifaciens JCM 18551 and Sphingomicrobium aestuariivivum KCTC 42286 were 32.7 and 28.4 %, respectively. The DNA G+C content of strain was 68.8 mol%. The phenotypic, chemotaxonomic and phylogenetic data indicated that strain CAU 1457 represents a novel species of the genus Sphingomicrobium, for which the name Sphingomicrobium arenosum sp. nov. is proposed. The type strain is CAU 1457 (=KCTC 62233=NBRC 113094).