Sphingomonas lacunae sp. nov., isolated from a freshwater pond

A novel bacterial strain, designated CSW-10^T, isolated from a freshwater pond in Taiwan, was characterized using a polyphasic taxonomic approach. Cells were Gram-stain-negative, aerobic, non-motile, rod-shaped and formed yellow-coloured colonies. Optimal growth occurred at 30 °C, pH 7, and in the absence of NaCl. Phylogenetic analyses based on 16S rRNA gene sequences and coding sequences of 92 protein clusters indicated that strain CSW-10^T formed a phylogenetic lineage in the genus Sphingomonas. The 16S rRNA gene sequence similarity indicated that strain CSW-10^T was most closely related to Sphingomonas fonticola TNR-2^T (97.6%). Strain CSW-10^T showed 69.8-70.7% average nucleotide identity and 19.0-23.0% digital DNA-DNA hybridization identity with the strains of other related Sphingomonas species. The major fatty acids of strain CSW-10^T were summed feature 8 (C_18:1 ω7c and/or C_18:1 ω6c) and C_17:1 ω6c. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, phosphatidyldimethylethanolamine, phosphatidylcholine, one uncharacterized sphingoglycolipid, five uncharacterized aminophospholipids, one uncharacterized phospholipid and one uncharacterized lipid. The predominant polyamines were homospermidine and spermidine. The major isoprenoid quinone was Q-10. Genomic DNA G+C content of strain CSW-10^T was 62.0 mol%. On the basis of phenotypic and genotypic properties and phylogenetic inference, strain CSW-10^T should represent a novel species of the genus Sphingomonas, for which the name Sphingomonas lacunae sp. nov. is proposed. The type strain is CSW-10^T (=BCRC 81190^T =LMG 31340^T).