Expanding the diversity of Desulfovibrio from the human gut: Desulfovibrio intestinivivus sp. nov., Desulfovibrio desulfopostgatei sp. nov. and Desulfovibrio faecalis sp. nov

Three strictly anaerobic, Gram‐negative, curved rod‐shaped bacteria, designated strains QI0430 ^T , QI0434 ^T and QI0442 ^T , were isolated from faecal samples of healthy adult donors in the UK. Phylogenomic analysis based on 31 single-copy marker genes showed that all three isolates formed distinct lineages. Whole-genome average nucleotide identity and digital DNA–DNA hybridization values between each isolate and its nearest phylogenetic neighbours were <95.6 and <63%, respectively, supporting their status as separate species. Genome sizes ranged from 3.41 to 3.59 Mb, with DNA G+C contents of 56.91–57.43 mol%. QI0430 was a non-motile, rod-shaped, catalase-negative bacterium that grew optimally at 37 °C, pH 7.5 and 0% (wt/v) NaCl. QI0434 was a motile, rod-shaped, catalase-negative bacterium that grew optimally at 30 °C, pH 7.0–8.0 and 0–0.9% (wt/v) NaCl. QI0442 was a non-motile, rod-shaped, catalase-negative bacterium that grew optimally at 30–37 °C, pH 9.0 and optimum 0% (wt/v) NaCl. Based on phylogenomic, phenotypic and chemotaxonomic differences, the following three novel species are proposed: Desulfovibrio intestinivivus sp. nov. (type strain QI0430 ^T =DSM 120530=NCIMB 15620 ^T ), Desulfovibrio desulfopostgatei sp. nov. (type strain QI0434 ^T =DSM 120532=NCIMB 15621 ^T ) and Desulfovibrio faecalis sp. nov. (type strain QI0442 ^T =DSM 120531=NCIMB 15622 ^T ).