Dyadobacter chenhuakuii sp. nov., Dyadobacter chenwenxiniae sp. nov., and Dyadobacter fanqingshengii sp. nov., isolated from soil of the Qinghai-Tibetan Plateau.

Six novel bacterial strains, designated CY22 ^T , CY357, LJ419 ^T , LJ53, CY399 ^T and CY107 were isolated from soil samples collected from the Qinghai-Tibetan Plateau, PR China. Cells were aerobic, rod-shaped, yellow-pigmented, catalase- and oxidase-positive, Gram-stain-negative, non-motile and non-spore-forming. All strains were psychrotolerant and could grow at 0 °C. The results of phylogenetic and phylogenomic analyses, based on 16S rRNA gene sequences and core genomic genes, indicated that the three strain pairs (CY22 ^T /CY357, LJ419 ^T /LJ53 and CY399 ^T /CY107) were closely related to members of the genus Dyadobacter and clustered tightly with two species with validly published names, Dyadobacter alkalitolerans 12116 ^T and Dyadobacter psychrophilus BZ26 ^T . Values of digital DNA-DNA hybridization between genome sequences of the isolates and other strains from the GenBank database in the genus Dyadobacter were far below the 70.0 % threshold. The genomic DNA G+C content of these six strains ranged from 45.2 to 45.8 %. The major cellular fatty acids of all six strains were iso -C _15 : 0 and summed feature 3 (comprising C _16 : 1 ω 7 c and/or C _16 : 1 ω 6 c ). MK-7 was the only respiratory quinone, and phosphatidylethanolamine was the predominant polar lipid for strains CY22 ^T , LJ419 ^T and CY399 ^T . On the basis of the phenotypic, phylogenetic and genomic evidence presented, these six strains represent three novel members of the genus Dyadobacter , for which the names Dyadobacter chenhuakuii sp. nov., Dyadobacter chenwenxiniae sp. nov. and Dyadobacter fanqingshengii sp. nov. are proposed. The type strains are CY22 ^T (= GDMCC 1.3045 ^T = KCTC 92299 ^T ), LJ419 ^T (= GDMCC 1.2872 ^T = JCM 33794 ^T ) and CY399 ^T (= GDMCC 1.3052 ^T = KCTC 92306 ^T ), respectively.