Sphingomonas folii sp. nov., Sphingomonas citri sp. nov. and Sphingomonas citricola sp. nov., isolated from citrus phyllosphere

Three novel Gram- stain-negative, aerobic and rod-shaped bacterial strains, designated RHCKR7(T), RRHST34(T) and RHCKR47(T), were isolated from phyllosphere of healthy citrus collected in Renhua County, Guangdong Province, PR China. Phylogenetic analyses showed that they belonged to the genus Sphingomonas, among which both strains RHCKR7(T) and RRHST34(T) showed a close relationship with Sphingomonas yunnanensis YIM 003(T) with 16S rRNA gene similarity of 99.0 and 99.1%, respectively, and the similarity between the two novel strains was 99.2%, meanwhile strain RHCKR47T was most closely related to Sphingomonas palmae KACC 17591(T) (99.5%). Genome-derived average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) values between closely related novel strains RHCKR7(T) and RRHST34(T) were 90.43 and 40.80 %, respectively, and their most closely related type strain, S. yunnanensis YIM 003(T), showed 90.43 % ANI and 40.7 % dDDH with RHCKR7(T) and 90.21 % and 42.9 % with RRHST34(T), respectively, and the corresponding values between strain RHCKR47(T) and S. palmae KACC 17591(T) were 85.53 % and 29.30%, respectively. They all took C-14:0 2-OH and summed feature 8 (C-18:1 omega 6c and/or C-18: 1 omega 7c) as the major fatty acids, and ubiquinone 10 as the predominant respiratory quinone. The major polar lipids contained sphingoglycolipid, phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylcholine and unidentified phospholipids. sym- Homospermidine was the major polyamine. Based on phenotypic, genotypic and chemotaxonomic analyses, the new isolates should be considered as representing three novel species of the genus Sphingomonas, for which the names Sphingomonas folli sp. nov., Sphingomonas citri sp. nov. and Sphingomonas citricola sp. nov. are proposed with RHCKR7(T) (=GDMCC 1.2663(T)=JCM 34794(T)), RRHST34(T) (=GDMCC 1.2665(T)=JCM 34796(T)) and RHCKR47(T) (=GDMCC 1.2664(T)=JCM 34795(T)) as the type strains, respectively.