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

Abstract

Abstract Three strictly anaerobic, Gram‐negative, curved rod‐shaped bacteria, designated strains QI0430T, QI0434T and QI0442T, 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 QI0430T=DSM 120530=NCIMB 15620T), Desulfovibrio desulfopostgatei sp. nov. (type strain QI0434T=DSM 120532=NCIMB 15621T) and Desulfovibrio faecalis sp. nov. (type strain QI0442T=DSM 120531=NCIMB 15622T).