A Gram-stain-negative, aerobic, non-motile, rod-shaped, catalase-positive and oxidase-positive bacteria (THG-T61T), was isolated from rhizosphere of Hibiscus syriacus. Growth occurred at 10-37 °C (optimum 25-30 °C), at pH 5.0-9.0 (optimum 7.0) and in the presence of 0-2.0 % NaCl (optimum without NaCl supplement). Based on 16S rRNA gene sequence analysis, the nearest phylogenetic neighbours of strain THG-T61T were identified as Sphingomonas ginsengisoli KCTC 12630T (97.9 %), Sphingomonas jaspsi DSM 18422T (97.8 %), Sphingomonas astaxanthinifaciens NBRC 102146T (97.4 %), Sphingomonassediminicola KCTC 12629T (97.2 %), 'Sphingomonas swuensis' KCTC 12336 (97.1 %) and Sphingomonas daechungensis KCTC 23718T (96.9 %). The isoprenoid quinone was ubiquinone-10 (Q-10). The major fatty acids were C16 : 0, C17 : 1ω6c, summed feature 4 (iso-C15 : 0 2-OH and/or C16 : 1ω7c) and summed feature 7 (C18 : 1ω7c, C18 : 1ω9t and/or C18 : 1ω12t). The polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine, sphingoglycolipid, one unidentified lipid, one unidentified phospholipid, one unidentified glycolipid and one unidentified phosphoglycolipid. The polyamine was homospermidine. The DNA G+C content of strain THG-T61T was 65.6 mol%. The DNA-DNA relatedness values between strain THG-T61T and its closest reference strains were less than 49.2 %, which is lower than the threshold value of 70 %. Therefore, strain THG-T61T represents a novel species of the genus Sphingomonas, for which the name Sphingomonas rhizophila sp. nov. is proposed. The type strain is THG-T61T (=KACC 19189T=CCTCC AB 2016245T).
Keywords: Hibiscus syriacus; Sphingomonas rhizophila; rhizosphere.