Sphingomonas Tabacisoli Sp Nov., A Member Of The Genus Sphingomonas, Isolated From Rhizosphere Soil Of Nicotiana Tabacum L.

A Gram-staining-negative, aerobic, motile and rod-shaped bacterium, designated strain X1-8(T), was isolated from rhizosphere soil of Nicotiana tabacum L.collected from the tobacco produce base located in Kunming, south-west PR China. Cells showed oxidase-negative and catalase-positive reactions and were motile by means of peritrichous flagella. Growth occurred at 2540 degrees C and pH 6.0-8.0 with optimal growth at 30-35(degrees)C, pH 7.0. The major respiratory lipoquinone was Q-10. C-16:0 and summed feature 8 (C-18:1 omega 7c and/or C-18:1 omega 6c) were identified as major cellular fatty acids. The profile of polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine, phosphatidylmethylethanolamine, sphingoglycolipid, phosphatidylcholine and one unidentified glycolipid. The major polyamine was sym-homospermidine. The genomic DNA G+C content was 66.5 mol%. The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that X1-8(T) should be affiliated to the genus Sphmgomonas and formed a clade with most closely related species Sphingomonas changbaiensis NBRC 104936(T). The results of 16S rRNA gene sequences similarity analysis indicated that X1-8(T) had the highest similarity with S. changbaiensis NBRC 104936(T) (98.4%) and lower than 96.0% with other species of the genus Sphingomonas. DNA-DNA hybridization data indicated that X1-8(T) represented a novel genomic species of the genus Sphingomonas. The characteristics determined in the polyphasic taxonomic study indicated that X1-8(T) represents a novel species of the genus Sphingomonas, for which the name Sphingomonas tabacisoh sp. nov. (type strain X1-8(T)=KCTC 62032(T)=CGMCC 1.16275(T)) is proposed.