Novosphingobium percolationis sp. nov. and Novosphingobium huizhouense sp. nov., isolated from landfill leachate of a domestic waste treatment plant.

Two strains designated as c1 and c7, were isolated from the landfill leachate of a domestic waste treatment plant in Huizhou City, Guangdong Province, PR China. The cells of both strains were aerobic, rod-shaped, non-motile and formed yellow colonies on Reasoner's 2A agar plates. Strain c1 grew at 10-42 °C (optimum, 30 °C), pH 4.5-10.5 (optimum, pH 7.0) and 0-2.0 % (w/v) NaCl (optimum, 0-0.5 %). Strain c7 grew at 10-42 °C (optimum, 30 °C), pH 4.5-10.5 (optimum, pH 6.0) and 0-2.0 % (w/v) NaCl (optimum, 0-0.5 %). Phylogenetic analyses revealed that strains c1 and c7 belong to the genus . The 16S rRNA gene sequence similarities of strains c1 and c7 to the type strains of species were 94.5-98.2 % and 94.3-99.1 %, respectively. The calculated pairwise average nucleotide identity values among strains c1, c7 and the reference strains were in the range of 75.2-85.9 % and the calculated pairwise average amino acid identity values among strains c1, c7 and reference strains were in the range of 72.0-88.3 %. Their major respiratory quinone was Q-10, and the major cellular fatty acids were C 7, C, C 7, C and C 2OH. The major polar lipids of strains c1 and c7 were phosphatidylethanolamine, diphosphatidylglycerol, phosphatidylglycerol, sphingoglycolipid, unidentified lipids and unidentified phospholipid. Based on phenotypic, chemotaxonomic, phylogenetic and genomic results from this study, strains c1 and c7 should represent two independent novel species of , for which the names sp. nov. (type strain c1=GDMCC 1.2555=KCTC 82826) and sp. nov. (type strain c7=GDMCC 1.2556=KCTC 82827) are proposed. The gene function annotation results of strains c1 and c7 suggest that they could play an important role in the degradation of organic pollutants.