Sphingopyxis ginsengisoli sp. nov., isolated from soil of a ginseng field in South Korea

Abstract

A Gram-negative, aerobic, motile, rod-shaped bacterium (strain Gsoil 250T) was isolated from soil of a ginseng field in Pocheon province (South Korea) and was characterized using a polyphasic approach in order to determine its taxonomic position. Comparative analysis of 16S rRNA gene sequences showed that strain Gsoil 250T belonged to the family Sphingomonadaceae of the class Alphaproteobacteria, and was related to Sphingopyxis macrogoltabida (98.7 %), Sphingopyxis chilensis (98.2 %), Sphingopyxis alaskensis (97.9 %), Sphingopyxis taejonensis (97.9 %) and Sphingopyxis witflariensis (97.8 %). The phylogenetic distance from any other species with validly published names within the genus Sphingopyxis was greater than 3.8 %. The G+C content of the genomic DNA of strain Gsoil 250T was 69.2 mol%. Strain Gsoil 250T contained Q-10 as the predominant respiratory lipoquinone and C18:1ω7c and summed feature 4 (C16:1ω7c and/or iso-C15:0 2-OH; 34.6 %) as the major fatty acids. No 3-hydroxy fatty acids were detected. Major polar lipids consisted of sphingoglycolipid, phosphatidylglycerol, phosphatidylcholine, phosphatidylethanolamine, diphosphatidylglycerol and two unknown glycolipids. Phenotypic and chemotaxonomic data supported the affiliation of strain Gsoil 250T to the genus Sphingopyxis. The results of DNA-DNA hybridization and physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain Gsoil 250T from the eight recognized Sphingopyxis species. Strain Gsoil 250T therefore represents a novel species, for which the name Sphingopyxis ginsengisoli sp. nov. is proposed, with the type strain Gsoil 250T (=KCTC 12582T=LMG 23390T).