Ktedonosporobacter rubrisoli gen. nov., sp. nov., a novel representative of the class Ktedonobacteria , isolated from red soil, and proposal of Ktedonosporobacteraceae fam. nov.

A novel filamentous, spore-forming, Gram-stain-positive bacterium, designated SCAWS-G2 ^T , was isolated from red soil in Jiangxi Province, PR China. The strain grew at 25-45 °C and at pH 4.0-7.0, and was able to tolerate up to 50 mM Zn ²⁺ . The complete genome of strain SCAWS-G2 ^T was a circular chromosome of ~11.34 Mb, which contained four 16S rRNA genes with three sequence types (0.4-0.8 % differences). Phylogenetic analysis based on 16S rRNA gene sequences showed that strain SCAWS-G2 ^T formed a distinct lineage within the order Ktedonobacterales , showing <89.2 % sequence similarities to the recognized taxa of this order. The whole-genome based phylogenomic tree separated strain SCAWS-G2 ^T from the recognized families within Ktedonobacterales . The genome-wide average nucleotide identity values between strain SCAWS-G2 ^T and the related type strains were <68.2 %. The strain can also be differentiated from the recognized families by a number of phenotypic characteristics. The polar lipids of SCAWS-G2 ^T were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, seven unidentified glycolipids and one unidentified lipid. The peptidoglycan amino acids contained ornithine, glycine, glutamic acid and alanine, and the cell-wall sugars were mainly galactose and rhamnose. The major fatty acids were C _16 : 1 2-OH, C _16 : 0 and iso-C _17 : 0 . Based on all these data, we propose that strain SCAWS-G2 ^T represents a novel genus and species, Ktedonosporobacter rubrisoli gen. nov., sp. nov., within the new family Ktedonosporobacteraceae fam. nov. of the order Ktedonobacterales . The type strain of Ktedonosporobacter rubrisoli is SCAWS-G2 ^T (=CGMCC 1.16132 ^T =DSM 105258 ^T ).