Culicoidibacter larvae gen. nov., sp. nov., from the gastrointestinal tract of the biting midge ( Culicoides sonorensis ) larva, belongs to a novel lineage Culicoidibacteraceae fam. nov., Culicoidibacterales ord. nov. and Culicoidibacteria classis nov. of the phylum Firmicutes

Strain CS-1 , a novel facultative anaerobic bacterium, was isolated from the larval gastrointestinal tract of the biting midge, , a vector of the epizootic haemorrhagic disease virus and the bluetongue virus. Cells were Gram-stain-positive, non-motile, non-spore-forming, pleomorphic rods. Optimal growth occurred at pH 7.5 and 37 °C. The G+C content of the genomic DNA was 38.3 mol%, estimated by using HPLC. The dominant cellular fatty acids were C (45.9 %) and C (26.6 %). The polar lipid profile comprised glycolipids, diphosphatidylglycerol, phospholipids and phosphoglycolipids. Respiratory quinones were not detected. Strain CS-1 had very low 16S rRNA gene similarity to members of the phylum : KM45013 (85 % similarity) and MOL361 (88 % similarity). Phylogenetic analysis based on 16S rRNA, genes, and conserved protein sequences of the whole genome revealed that strain CS-1 was related to members of the classes and within the phylum . Furthermore, average nucleotide identity and digital DNA-DNA hybridization analyses of the whole genome revealed very low sequence similarity to species of and ( KM45013 and sp. H121). These results indicate that strain CS-1 belongs to the phylum and represents a new species of a novel genus, family, order and class. Based on the phenotypic, chemotaxonomic, phylogenetic and genomic characteristics, we propose the novel taxon gen. nov., sp. nov. with the type strain CS-1 (=CCUG 71726 =DSM 106607 ) within the hereby new proposed novel family fam. nov., new order ord. nov. and new class classis nov. in the phylum .