Spirosoma gilvum sp. nov., Isolated from Beach Soil

A Gram-reaction-negative, nonmotile, rod-shaped, aerobic bacterial strain, designated 15J10-9T5T, was isolated from beach soil on Jeju Island, South Korea, and was characterized taxonomically using a polyphasic approach. Comparative 16S rRNA gene sequence analysis showed that the isolate belonged to the family Cytophagaceae in the phylum Bacteroidetes, and was most closely related to Spirosoma aerolatum PR1012kT (96.1%) and Spirosoma panaciterrae DSM 21099T (95.7%). The detection of menaquinone MK-7 as the predominant respiratory quinone, a fatty acid profile with summed feature 3 (C16:1ω7c/C16:1ω6c), C16:1ω5c, and iso-C15:0 as the major components, and a polar lipid profile with phosphatidylethanolamine as the major component also supported the affiliation of strain 15J10-9T5T in the genus Spirosoma. The G+C content of the genomic DNA was 47.7 mol %. The isolate could be clearly differentiated from its closest neighbors based on its phenotypic, phylogenetic, chemotaxonomic, and genotypic features. Therefore, strain 15J10-9T5T represents a novel species of the genus Spirosoma, for which the name Spirosoma gilvum sp. nov. is proposed. The type strain is 15J10-9T5T (=KCTC 52033T = JCM 31997T).