Sphingobium chungangianum sp. nov., isolated from rhizosphere of Pinus koraiensis

Abstract

A novel Gram-staining negative, yellow-pigmented, non-motile, aerobic and rod-shaped bacterium, designated MAH-11 T , was isolated from rhizosphere of Pinus koraiensis and was characterised by using a polyphasic taxonomic approach. The colonies were smooth, circular and 0.3–1.0 mm in diameter when grown on R2A agar for 3 days. The strain was positive for both catalase and oxidase tests. Optimum growth temperature and pH were 28–30 °C and 7.0, respectively. Cell growth occurs on R2A agar, nutrient agar, Luria–Bertani agar and tryptone soya agar but not on MacConkey agar. The novel strain was found to be able to hydrolyse esculin but not casein, gelatin, starch, l-tyrosine, DNA, l-arginine, urea, Tween 20 and Tween 80. On the basis of 16S rRNA gene sequence analysis, strain MAH-11 T belongs to the genus Sphingobium and is closely related to Sphingobium quisquiliarum P25 T (98.1%), Sphingobium vermicomposti VC-230 T (97.8%), Sphingobium mellinum WI4 T (97.5%), Sphingobium barthaii KK22 T (97.2%) and Sphingobium fuliginis TKP T (97.2%). In DNA–DNA hybridization tests, the DNA relatedness values between strain MAH-11 T and its close phylogenetic neighbors were below 45.0%. The DNA G+C content was 64.5 mol% and the predominant respiratory quinone was identified as ubiquinone-10. The major cellular fatty acids were summed feature 8 (C 18:1 ω7c and/or C 18:1 ω6c), summed feature 3 (C 16:1 ω7c and/or C 16:1 ω6c) and C 16:0 . The DNA–DNA hybridization results in combination with chemotaxonomic and physiological data demonstrated that strain MAH-11 T represents a novel species within the genus Sphingobium, for which the name Sphingobium chungangianum is proposed. The type strain is MAH-11 T (= KACC 19836 T = CGMCC 1.13749 T ). © 2019, Springer Nature Switzerland AG.