Description of a Gram-negative bacterium, Sphingomonas guangdongensis sp. nov

A Gram-stain-negative bacterial strain, designated 9NM-8T, was isolated from an abandoned lead-zinc ore in Mei county, Meizhou, Guangdong province, PR China. The isolate was orange-pigmented, aerobic, oxidase- and catalase-positive, motile with lophotrichous flagella and rod-shaped. Strain 9NM-8T grew optimally at pH 7.0 and 30 °C and in the absence of NaCl on R2A agar. Phylogenetic analysis based on 16S rRNA gene sequences showed that strain 9NM-8T belongs to the genus Sphingomonas, with highest sequence similarities to Sphingomonas azotifigens KACC 14484T (96.1%), Sphingomonas trueperi DSM 7225T (96.0%) and Sphingomonas pituitosa DSM 13101T (95.6 %). Strain 9NM-8T contained Q-10 as the predominant ubiquinone. The major fatty acids included C18:1ω7c, C16:0, C16:1ω7c and/or C16 : 1ω6c (summed feature 3) and 11-methyl C18:1ω7c. The DNA G+C content was 69.6±1.3 mol%. The major component in the polyamine pattern was sym-homospermidine and the polar lipid profile contained sphingoglycolipid, phosphatidylcholine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, an unidentified glycolipid and two unidentified phospholipids. Based on comparative analysis of physiological, chemotaxonomic and phylogenetic characteristics, strain 9NM-8T should be considered to represent a novel species of the genus Sphingomonas, for which the name Sphingomonas guangdongensis sp. nov. is proposed. The type strain is 9NM-8T (=GIMCC 1.653T=CGMCC 1.12672T=DSM 27570T).