Sphingobium lignivorans sp. nov., isolated from river sediment downstream of a paper mill.

A bacterial isolate, B1D3A, was isolated from river sediment collected from the Hiwassee River near Calhoun, TN, by enrichment culturing with a model 5-5' lignin dimer, dehydrodivanillate, as its sole carbon source. B1D3A was also shown to utilize several model lignin-derived monomers and dimers as sole carbon sources in a variety of minimal media. Cells were Gram-stain-negative, aerobic, motile, rod-shaped and formed yellow/cream-coloured colonies on rich agar. Optimal growth occurred at 30 °C, pH 7-8, and in the absence of NaCl. The major fatty acids of B1D3A were C ω7 and C ω6. The predominant hydroxy fatty acids were C 2-OH and C 2-OH. The polar lipid profile consisted of a mixture of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidyldimethylethanolamine and sphingoglycolipid. B1D3A contained spermidine as the only major polyamine. The major isoprenoid quinone was Q-10 with minor amounts of Q-9 and Q-11. The genomic DNA G+C content of B1D3A was 65.6 mol%. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 49 core, universal genes defined by Clusters of Orthologous Groups gene families indicated that B1D3A was a member of the genus . B1D3A was most closely related to sp. SYK-6, with a 100 % 16S rRNA gene sequence similarity. B1D3A showed 78.1-89.9 % average nucleotide identity and 19.5-22.2% digital DNA-DNA hybridization identity with other type strains from the genus . On the basis of phenotypic and genotypic properties and phylogenetic inference, strain B1D3A should be classified as representing a novel species of the genus , for which the name sp. nov. is proposed. The type strain is strain B1D3A (ATCC TSD-279=DSM 111877).