A bacterial strain, designated JS7-11T, was isolated from the surface sediment of the Jiulong River and characterized using a polyphasic taxonomic approach. Cells of JS7-11T were Gram-staining-negative, non-motile and short-rod-shaped. Growth was observed at 10-40 °C (optimum 25-30 °C), at pH 6-8 (optimum 7) and in 1-12 % NaCl (optimum 3-4 %, w/v). The results of phylogenetic analysis based on 16S rRNA gene sequences indicated that JS7-11T and Nioella nitratireducens SSW136T formed an independent cluster, sharing 97.9 % similarity between the two strains, and less than 96.0 % similarities with other type strains of members of the family Rhodobacteraceae. The major fatty acids were summed feature 8 and C16 : 0. The quinone was identified as Q-10. The polar lipids comprised phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol and two unidentified phospholipids. The DNA G+C content was 63.4 mol%. The digital DNA-DNA hybridization and average nucleotide identity values between JS7-11T and N. nitratireducens SSW136T were 22.1 and 79.4 %, respectively. The results of phenotypic, phylogenetic and chemotaxonomic analyses clearly indicated that JS7-11T represents a novel species within the genus Nioella, for which the name Nioellasediminis sp. nov. is proposed. The type strain of the novel species is JS7-11T (=MCCC 1A00710T=KCTC 42144T).