Spirosoma luteolum sp. nov. isolated from water.

A novel Gram-negative and rod-shaped bacterial strain, designated as 16F6E, was isolated from a water sample. Cells were yellowish in color and catalase- and oxidase-positive. The strain grew at 10-37°C (optimum at 25°C) but not at 4 and 42°C, and pH 5-7 (optimum at pH 7). It showed moderate resistance to gamma-ray irradiation. Comparative phylogenetic analysis showed that strain 16F6E belonged to the family Cytophagaceae of the class Cytophagia. Furthermore, this isolate showed relatively low 16S rRNA gene sequence similarities (90.7-93.1%) to the members of the genus Spirosoma. The major fatty acids were summed feature 3 (C ω7c/C ω6c), C ω5c, C N alcohol, and C. The polar lipid profile indicated presence of phosphatidylethanolamine, unknown aminophospholipids, an unknown amino lipid, unknown phospholipids, and unknown polar lipids. The predominant isoprenoid quinone was MK-7. The genomic DNA G+C content of strain 16F6E was 56.5 mol%. Phenotypic, phylogenetic, and chemotaxonomic properties indicated that isolate 16F6E represents a novel species within the genus Spirosoma, for which the name Spirosoma luteolum sp. nov. is proposed. The type strain is 16F6E (=KCTC 52199 =JCM 31411).