Spirosoma fluminis sp. nov., a Gamma-Radiation Resistant Bacterium Isolated from Sediment of the Han River in South Korea.

A Gram-negative, long rod-shaped, and yellowish bacterium, designated as strain 15J17T, was isolated from sediment of the Han River in South Korea after exposure to 3 kGy of gamma radiation. The strain was catalase- and oxidase-positive and showed resistance to gamma radiation-D value (i.e., the dose required to reduce the bacterial population by 10-fold) of >4 kGy. Phylogenetic analysis based on the 16S rRNA gene sequence revealed that the strain belonged to the genus Spirosoma and showed moderate degrees of sequence similarity with related species (90.6-93.5 %). Chemotaxonomic data revealed that the strain contained summed feature 3 (C ω7 c/C ω6 c), C ω5 c, C, C, and C iso as the major fatty acids; phosphatidylethanolamine, an unidentified aminophospholipid, and an unidentified polar lipid as the major polar lipids; and menaquinone-7 (MK-7) as the major quinone. The genomic DNA G+C content of the new strain was 48.3 mol%. Based on these data, type strain 15J17T (=KCTC 52198 = JCM 31409) should be classified as representing a new species, for which we propose the name Spirosoma fluminis sp. nov. [ABSTRACT FROM AUTHOR]