A Gram-stain-negative, rod-shaped, bright-orange coloured bacterium without flagellum, designated as strain GRR-S6-50T, was isolated from a tidal flat of Garorim bay, Taean-gun, Chungcheongbuk-do, Republic of Korea. Cells grew aerobically at 20-37 °C (optimum, 30 °C), pH 7.0-10.0 (optimum, pH 7.0) and with 1-5 % (w/v) NaCl (optimum, 3 %). The 16S rRNA gene sequence analysis demonstrated that strain GRR-S6-50T was closely related to Sphingomicrobium aestuariivivum AH-M8T with a sequence similarity of 97.80 % followed by Sphingomicrobium astaxanthinifaciens CC-AMO-30BT (97.44 %), Sphingomicrobium marinum CC- AMZ-30MT (97.16 %), Sphingomicrobium arenosum CAU 1457T (96.37 %), Sphingomicrobium flavum CC-AMZ-30NT (95.31 %) and Sphingomicrobium lutaoense CC-TBT-3T (95.23 %). The average nucleotide identity and digital DNA-DNA hybridization values with related strains ranged from 74.5 to 77.3% and 21.1 to 35.0 %, respectively. The G+C content of strain GRR-S6-50T was 63.30 mol%. The strain has ubiquinone-10 as the predominant respiratory quinone and the major fatty acids were C18 : 3 ω6c (54.57 %) and C17 : 1 ω6c (10.58 %). The polar lipids consisted of phosphatidylethanolamine, phosphatidylglycerol, three unidentified lipids and one glycolipid. On the basis of the results of phylogenetic, phenotypic and chemotaxonomic studies, strain GRR-S6-50T is regarded to represent a novel species within the genus Sphingomicrobium, for which the name Sphingomicrobium sediminis sp. nov. (KACC 22562T=KCTC 92123T=JCM 35084T) is proposed.
Keywords: Sphingomicrobium; marine bacteria; polyphasic approach; tidal flats.