Sphingobium pinisoli sp. nov., isolated from the rhizosphere soil of a Korean native pine tree

A Gram-stain negative, aromatic compound degrading bacterium, designated strain ASA28T, was isolated from the rhizosphere soil of a pine tree at Anmyon island, Taean in Korea. Strain ASA28T was found to be strictly aerobic, non-motile, short rods which can grow at 15–28 °C (optimum, 25–28 °C), at pH 5.0–11.0 (optimum, pH 7.0) and at salinities of 0–1.0% (w/v) NaCl (optimum, 0% NaCl). Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain ASA28T belongs to the genus Sphingobium, showing high sequence similarity to Sphingobium scionense WP01T (97.8%), Sphingobium vermicocomposti VC-230T (96.8%), Sphingobium yanoikuyae ATCC 51230T (96.5%) and Sphingobium herbicidovorans MHT (95.6%). The predominant ubiquinone and polyamine components were identified as Q-10 and spermidine, respectively. The major fatty acids were identified as C18:1ω7c, C16:0, C14:0 2-OH and C16:1ω7c and/or C15:0 iso 2-OH. The major polar lipids were identified as diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmonomethylethanolamine, phosphatidylcholine, sphingoglycolipid, phosphoglycolipid, four unidentified aminophospholipids, an unidentified aminolipid, two unidentified phospholipids and six unidentified lipids. The DNA G+C content of this novel isolate was determined to be 63.0 mol%. DNA–DNA relatedness between strain ASA28T and S. herbicidovorans KCTC 2939T, S. vermicocomposti DSM 21299T and S. scionense DSM 19371T was determined to be 32 ± 5%, 30 ± 4% and 25 ± 5%, respectively. On the basis of the phylogenetic, phenotypic and chemotaxonomic analyses in this study, strain ASA28T is considered to represent a novel species of the genus Sphingobium, for which the name Sphingobium pinisoli sp. nov. is proposed. The type strain is ASA28T (= KACC 18700T = NBRC 112246T).