Novosphingobium fluoreni sp. nov., isolated from rice seeds.

A yellow-pigmented, Gram-stain-negative, rod-shaped, non-spore-forming bacterium designated strain HLJ-RS18(T), which could degrade fluorene, was isolated from rice seeds collected from Heilongjiang Province, China. Similarities of full-length of 16S rRNA gene sequences between strain HJL-RS18(T) and the type strains of the genus Novosphingobium with validly published names ranged from 93.8 to 97.1%. Phylogenetic analysis with maximum-likelihood and neighbour-joining methods revealed that strain HLJ-RS18(T) belonged to genus Novosphingobium and strain HLJ-RS18(T) formed a distinct clade to Novosphingobium chloroacetimidivorans BUT-14(T) (96.9% similarity based on 16S rRNA gene). DNA-DNA hybridization of HLJ-RS18(T) and BUT-14(T) showed a low relatedness value of 22.4 ± 0.9%, which indicated that strain HLJ-RS18(T) represents a novel species of the genus Novosphingobium. The genomic DNA G+C content of strain HLJ-RS18(T) was 62 mol%. Ubiquinone Q-10 was the major respiratory quinone. Spermidine was the predominant polyamine. Polar lipids consisted mainly of aminophospholipid, phosphatidylglycerol, phosphatidylethanolamine, phospholipid and sphingoglycolipid. The predominant fatty acid composition of HLJ-RS18(T) were summed 8 (C(18:1)ω7c and/or C(18:1)ω6c, 61.5%), C(16 : 0) (14.2%), summed 3 (C(16:1)ω7c and/or C(16:1)ω6c, 13.5%) and C14:0 2-OH (6.8%). Phylogenetic analysis, DNA-DNA hybridization, chemotaxonomic data and phenotypic characteristics support the conclusion that HLJ-RS18(T) represents a novel species within the genus Novosphingobium. Therefore, we propose the species Novosphingobium fluoreni sp. nov. with HLJ-RS18(T) ( = DSM 27568(T) = ACCC19180(T)) as the type strain.