A Gram-stain-negative bacterium, designated XZ-24 , was isolated from sediment of a river in Mianyang city, Sichuan province, PR China. Cells (1.0-2.0 µm long and 0.4-0.5 µm in width) were strictly aerobic, non-spore-forming, rod shaped, prosthecate and motile by means of a polar flagellum. Growth occurred at 10-37 °C (optimum, 30 °C), at pH 5.0-9.0 (optimum pH 7.0) and with 0-3.0 % (w/v) NaCl (optimum 1.0 % NaCl). The results of phylogenetic analysis based on genomes and 16S rRNA gene sequences indicated that XZ-24 formed a distinct phyletic branch within the family and was most closely related to members of the genera , and with 95.3-96.5 % 16S rRNA gene sequence similarities. The average amino acid identities (AAI) between XZ-24 and species of the family were 47.0-64.5 %, which were below the genus boundary (70 %). The predominant cellular fatty acids were summed feature 8 (C ω7 and/or C ω6 ), C , C ω7 11-methyl and summed feature 3 (C ω7 and/or C ω6 ), the isoprenoid quinone was Q-10, and the major polar lipids were 1,2-di-O-acyl-3-O-α-d-glucopyranuronosyl glycerol; 1,2-di-O-acyl-3-O-d-glucopyranosyl-(1→4)-α-d glucopyranuronosyl glycerol and phosphatidylglycerol. The genome size of XZ-24 was 2.64 Mb with a DNA G+C content of 68.9 %. On the basis of the evidence presented in this study, strain XZ-24 represents a novel species of a novel genus in the family , for which the name gen. nov., sp. nov. (Type strain XZ-24 =CCTCC AB 20 23 094 =KCTC 8038 ) is proposed.