Polaromonas ginsengisoli sp. nov., isolated from ginseng field soil.

ABSTRACT

A Gram-reaction-negative, strictly aerobic, milky-white and rod-shaped bacterium (designated Gsoil 115T) isolated from ginseng field soil was characterized by a polyphasic approach to clarify its taxonomic position. Strain Gsoil 115T grew optimally at 30 °C and at pH 7.0 on Reasoner's 2A agar medium. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain Gsoil 115T belongs to the genus Polaromonas and was most closely related to Polaromonaseurypsychrophila B717-2T (98.6 %), Polaromonasvacuolata 34-PT (98.3 %), Polaromonasjejuensis NBRC 106434T (98.1 %), Polaromonas aquatic CCUG 39402T (97.7 %) and Polaromonascryoconiti Cr4-35T (97.5 %). The DNA G+C content was 60.9 mol%. The DNA-DNA hybridization relatedness between strain Gsoil 115T and P. eurypsychrophila B717-2T, P. vacuolata 34-PT, P. jejuensis NBRC 106434T, P. aquatic CCUG 39402T and P. cryoconiti Cr4-35T were 31.2, 21.6, 16.9, 8.7 and 10.1 %, respectively. The major polar lipids were phosphatidylglycerol (PG), diphosphatidylglycerol (DPG) and phosphatidylethanolamine (PE). The sole respiratory quinone was Q-8. The major fatty acids were C16  0 and summed feature 3 (C16  1ω7c and/or C16  1ω6c), which supported the affiliation of strain Gsoil 115T to the genus Polaromonas. Moreover, the physiological, biochemical and low level of DNA-DNA relatedness value allowed the phenotypic and genotypic differentiation of strain Gsoil 115T from the recognized species of the genus Polaromonas. Therefore, strain Gsoil 115T represents a novel species of the genus Polaromonas, for which the name Polaromonas ginsengisoli sp. nov. is proposed, with the type strain Gsoil 115T (LMG 23393T=KCTC 12577T).