The order Solirubrobacterales is a deep-branching lineage within the phylum Actinomycetota. Most representatives have been isolated from terrestrial environments. A strain isolated from a grassland soil was found to be affiliated with this order and therefore characterized by a polyphasic approach. Cells of strain 0166_1T are Gram-positive, short rods, non-motile, non-spore-forming and divide by binary fission. A surface layer with protrusions covers the majority of the cells. Strain 0166_1T grows optimally around neutral to slightly alkaline pH (pH 7.1-7.9) and at temperatures between 24-36 °C in SSE/HD 1 : 10 medium. It grows optimally with 0-0.5% NaCl (w/v) but can withstand concentrations up to 5 %. The major fatty acids are C18 : 1 ω9c, C16 : 1 ω7c, C17 : 0 cyclo ω7c, C18 : 1 ω7c methyl and C19 : 0 cyclo ω9c. The major polar lipids are diphosphatidylglycerol, two unidentified phospholipids and one unidentified glycolipid. MK-7(H4) and MK-7(H2) are the predominant respiratory quinones. meso-2,6-Diaminopimelic acid is the diagnostic diamino acid in the cell-wall peptidoglycan. The G+C content for strain 0166_1T is 72.8 mol%. 16S rRNA gene sequence analysis indicated that this bacterium was related to Conexibacter arvalis KV-962T and Conexibacter stalactiti YC2-25T with 95.5 and 95.2 % sequence similarity, respectively. Based on the phenotypic, genomic and phylogenetic data, we propose the novel species Capillimicrobium parvum sp. nov. (type strain 0166_1T=DSM 104329T=LMG 29999T=CECT 9240T) of the novel genus Capillimicrobium gen. nov. within the novel family Capillimicrobiaceae fam. nov.
Keywords: Capillimicrobium; halotolerant; high G+C content; soil bacterium.