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

A Gram-reaction-negative, strictly aerobic, milky-white and rod-shaped bacterium (designated Gsoil 115) isolated from ginseng field soil was characterized by a polyphasic approach to clarify its taxonomic position. Strain Gsoil 115 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 115 belongs to the genus Polaromonas and was most closely related to Polaromonaseurypsychrophila B717-2 (98.6 %), Polaromonasvacuolata 34-P (98.3 %), Polaromonasjejuensis NBRC 106434 (98.1 %), Polaromonas aquatic CCUG 39402 (97.7 %) and Polaromonascryoconiti Cr4-35 (97.5 %). The DNA G+C content was 60.9 mol%. The DNA-DNA hybridization relatedness between strain Gsoil 115 and P. eurypsychrophila B717-2, P. vacuolata 34-P, P. jejuensis NBRC 106434, P. aquatic CCUG 39402 and P. cryoconiti Cr4-35 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 115 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 115 from the recognized species of the genus Polaromonas. Therefore, strain Gsoil 115 represents a novel species of the genus Polaromonas, for which the name Polaromonas ginsengisoli sp. nov. is proposed, with the type strain Gsoil 115 (LMG 23393=KCTC 12577).