Dysosmobacter welbionis gen. nov., sp. nov., isolated from human faeces and emended description of the genus Oscillibacter

• Published in: International journal of systematic and evolutionary microbiology Vol. 70; no. 9; pp. 4851 - 4858
• Main Authors: Le Roy, Tiphaine, Van der Smissen, Patrick, Paquot, Adrien, Delzenne, Nathalie, Muccioli, Giulio G, Collet, Jean-François, Cani, Patrice D
• Format: Journal Article
• Language: English
• Published: England 01.09.2020
• ISSN: 1466-5026; 1466-5034
• DOI: 10.1099/ijsem.0.003547

A strictly anaerobic, Gram-stain-negative, non-spore-forming, non-motile, non-pigmented bacterium, strain J115 , was isolated from human faeces. Cells of strain J115 were straight rods, generally 1.8-3.0 µm, but could be up to 18 µm long. Growth occurred below 2 % (w/v) NaCl and 2 % (v/v) bile. Strain J115 produced acid from myo-inositol but not from d-glucose, d-ribose or d-xylose. Butyric acid was the major end-product from myo-inositol. The genomic DNA G+C content was 58.92 mol%. Phylogenetic analysis based on 16S rRNA gene sequencing indicated that the closest cultivated neighbours of strain J115 were Oscillibacterruminantium GH1 (95.4 % similarity) and Oscillibactervalericigenes Sjm18-20 (94.1 %). Strain J115 was also related to the not-yet-cultured bacterium Oscillospiraguilliermondii (92-93 % similarity). Coherently with the 16S rRNA gene sequence results, the average nucleotide identity scores of strain J115 to O. ruminantium GH1 and O. valericigenes Sjm18-20 were 73.37 and 73.24, respectively, while in silico estimations of DNA-DNA hybridization were both 20.4 %, with confidence intervals of 18.2 - 22.9 % and 18.2 - 22.8 %, respectively. The major fatty acids were iso-C15 : 0 (24.2 %), C18 : 0 DMA (18.4 %), anteiso-C15 : 0 (15.2 %) and C16 : 0 DMA (7.6 %). No respiratory quinone was detected. Based on phenotypic features and phylogenetic position, it is proposed that this isolate represents a novel species in a new genus, Dysosmobacterwelbionis gen. nov., sp. nov. The type strain of Dysosmobacterwelbionis is J115 (DSM 106889 = LMG 30601 ).