Proposal of Sphingomicrobium lutaoense gen. nov. , sp. nov., isolated from a coastal hot spring of Green Island (Lutao).

Abstract

A yellowish pigmented, Gram-negative, rod-shaped, non-spore-forming bacterium (strain CC-TBT-3T), was isolated from coastal hot spring of Green Island (Lutao), located off Taituang, Taiwan, on Marine Agar 2216. The 16S rRNA gene sequence analysis of strain CC-TBT-3T showed a relatively low (< 95.5%) to representatives of the genera Novosphingobium, Sphingosinicella and Sphingomonas of the Sphingomonadaceae with Novosphingobium soli as the most similar species. Beside the relatively low 16S rRNA gene sequence similarity to established species, this isolated showed also some chemotaxonomic unique features, like the presence of some glycolipids with unusual chromatographic behavior. The polar lipid profile was composed of the major lipids diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, sphingoglycolipid, and three unidentified glycolipids. The major respiratory quinone was ubiquinone Q-10, The polyamine pattern was characterized by the major triamine sym-homospermidine. Although the predominant fatty acids were C18:1 ω7c and 16:1 ω7c and/or 15 iso 2-OH (detected as summed feature 3), the isolate did not show the typical hydroxyl fatty acids, like C14:0 2-OH, C15:0 2-OH, and C16:0 2-OH found in Novosphingobium, Sphingomonas and Sphingosinicella, but showed instead high amounts of C18:1 2-OH (12.0%). The DNA G+C content of the strain CC-TBT-3T was 63.4 mol %. Characterization by 16S rRNA gene sequence, chemotaxonomic and physiological revealed that strain CC-TBT-3T represents a new genus in the family Sphingomonadaceae. For this reason we propose the name Sphingomicrobium lutaoense gen, nov. sp. nov. with the type strain CC-TBT-3T (= DSM 24194T = CCM 7794T).