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.