A Gram-stain-negative, rod-shaped, strictly aerobic, flagellated and non-spore-forming marine bacterium designated strain CC-AMO-30B(T) was isolated from coastal surface seawater, Taiwan. Strain CC-AMO-30B(T) synthesized astaxanthin [40 ?g (g dry weight)(-1)] and formed reddish-orange-coloured colonies on marine agar (Difco 2216). The strain showed highest pairwise 16S rRNA gene sequence similarity to Sphingomicrobium lutaoense CC-TBT-3(T) (96.4%) followed by other members of the family Sphingomonadaceae (<94%) and established a discrete phyletic lineage associated with the former. The polar lipid profile constituted a remarkable number of unidentified glycolipids (GL1-8), in addition to diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid and two unidentified lipids (L1-2). The major fatty acids (>5% of total fatty acids) were C(18:1)�s7c/C(18:1)�s6c (summed feature 8), C(16:1)�s7c/C(16:1)�s6c (summed feature 3), C(18:1) 2-OH, methyl C(18:1)�s7c, C(17:1)�s6c and C(16 : 0). DNA G+C content was 70.6%; major respiratory quinone was ubiquinone Q-10; predominant polyamine was the triamine sym-homospermidine. Chemotaxonomic evidence including characteristic glycolipid profile, presence of significant amounts of C(18:1) 2-OH and absence of typical hydroxylated fatty acids such as C(14:0) 2-OH, C(15:0) 2-OH and C(16:0) 2-OH in considerable amounts, accompanied by phylogenetic distinctiveness and several other phenotypic features support the classification of strain CC-AMO-30B(T) as a representative of a novel species within the genus Sphingomicrobium for which the name Sphingomicrobium astaxanthinifaciens sp. nov. is proposed; the type strain is CC-AMO-30B(T) (=JCM 18551(T) =BCRC 80465(T)).