Sphingomonas ginsengisoli sp. nov. and Sphingomonas sediminicola sp. nov.

Abstract

Two novel bacteria, designated strains Gsoil 634T and Dae 20T, were isolated in South Korea from soil of a ginseng field and freshwater sediment, respectively and were characterized by a polyphasic approach to clarify their taxonomic positions. Phylogenetic analysis based on 16S rRNA gene sequences indicated that, although they probably represented two distinct species (indicated by a sequence similarity of 96.6 %), both strain Gsoil 634T and strain Dae 20T belonged to the genus Sphingomonas and were most closely related to ‘Sphingomonas humi’ PB323 (97.8 % and 96.7 % sequence similarity, respectively), Sphingomonas kaistensis PB56T (96.8 % and 96.7 %), Sphingomonas astaxanthinifaciens TDMA-17T (96.6 % and 95.4 %) and Sphingomonas jaspsi TDMA-16T (95.6 % and 95.8 %). For both novel strains, the major ubiquinone was Q-10, the major polyamine was homospermidine, the major cellular fatty acids included summed feature 7 (C18 : 1ω7c, C18 : 1ω9t and/or C18 : 1ω12t), C17 : 1ω6c and C16 : 0, and the polar lipids included sphingoglycolipid. These chemotaxonomic data supported the affiliation of both strains to the genus Sphingomonas . However, the DNA–DNA relatedness value between strain Gsoil 634T and ‘Sphingomonas humi’ PB323T was 31 %. Moreover, the results of physiological and biochemical tests allowed the phenotypic differentiation of strains Gsoil 634T and Dae 20T from established members of the genus Sphingomonas . Based on these data, the two isolates represent two novel species in the genus Sphingomonas , for which the names Sphingomonas ginsengisoli sp. nov. (type strain Gsoil 634T = KCTC 12630T = DSM 18094T = LMG 23739T) and Sphingomonas sediminicola sp. nov. (type strain Dae 20T  = KCTC 12629T = DSM 18106T = LMG 23592T) are proposed.