Two Gram-negative, facultatively anaerobic, catalase-positive, oxidase-negative, non-motile, rodshaped and moderately halophilic bacterial strains, designated YIM 90637 T and BH 017, were isolated from a salt lake in Xinjiang province, north-west China, and subjected to a polyphasic taxonomic study. Phylogenetic analysis based on 16S rRNA gene sequences revealed that the two novel isolates were affiliated with the family Halomonadaceae; the two strains shared 100 % sequence similarity, but showed similarities of 94.7 % with the type strain of Modicisalibacter tunisiensis, 93.2-94.7 % with members of the genus Chromohalobacter, 93.2-95.0 % with members of the genus Halomonas and less than 92.0 % with other members of the family Halomonadaceae. However, DNA-DNA relatedness data and phenotypic properties demonstrated that strains YIM 90637 T and BH 017 were representatives of the same species. The major fatty acids were C 19 : 0 cyclo v8c and C 16 : 0. The relative amount of C 19 : 0 cyclo v8c was notably higher than that found in most species of the family Halomonadaceae for which fatty acid composition has been determined. The genomic DNA G+C content was 57.2-57.5 mol% and the only respiratory quinone was ubiquinone 9. Based on evidence from the polyphasic taxonomic study, it was concluded that the two strains should be classified as representatives of a novel species in a new genus, for which name Aidingimonas halophila gen. nov., sp. nov. is proposed; the type strain of Aidingimonas halophila is YIM 90637 T (5KCTC 12885 T 5CCTCC AB 207002 T ).The family Halomonadaceae was first proposed on the basis of results obtained with the 16S rRNA cataloguing technique (Franzmann et al., 1988). The family Halomonadaceae belongs to the class Gammaproteobacteria and, at the time of writing, included four genera of halophilic bacteria (Halomonas, Chromohalobacter, Modicisalibacter and Cobetia) and three genera of non-halophilic bacteria (Zymobacter, Halotalea and Carnimonas) (Okamoto et al., 1993;Dobson & Franzmann, 1996;Mata et al., 2002;Ventosa et al., 1998; Ben Ali Gam et al., 2007;Ntougias et al., 2007). Halomonas is the largest genus in the family Halomonadaceae and currently comprises more than 50 species. More than half of the taxa in the family Halomonadaceae have been reclassified because of their heterogeneous features (Franzmann et al., 1988;Mellado et al., 1995;Dobson & Franzmann, 1996; Arahal et al., 2002a, b) and the description of the family has been emended three times (Dobson & Franzmann, 1996;Ntougias et al., 2007; Ben Ali Gam et al., 2007). Nevertheless, the taxonomic status of some taxa, e.g. Cobetia marina, Halomonas marisflavi, Halomonas indalinina, Halomonas avicenniae and Halomonas salaria, is still 3These authors contributed equally to this work.The GenBank/EMBL/DDBJ accession numbers for the 16S rRNA gene sequences of strains YIM 90637 T and BH 017 are FJ418176 and EU191906, respectively.The polar lipid composition of strain YIM 90637 T and the cellular fatty acid profiles of strains YIM 90637 T ...