Sporaefaciens musculi gen. nov., sp. nov., a novel bacterium isolated from the caecum of an obese mouse

A bacterial strain, designated WCA-9-b2, was isolated from the caecal content of an 18-week-old obese C57BL/6NTac male mouse. According to phenotypic analyses, the isolate is rod-shaped, Gram-positive, strictly anaerobic, spore-forming and non-motile under the conditions tested. Bacterial colonies were irregular and non-pigmented.

Analysis of the 16S rRNA gene indicated that the isolate belonged to the family Lachnospiraceae with Clostridium scindens ATTC 35704 (94.9% sequence identity) and Dorea formicigenerans ATCC 27755 (94.8%) being the closest relatives.

Whole genome sequencing showed average nucleotide identity (ANI) ranging from 69.80–74.23% and percentage of conserved proteins (POCP) values < 50% against the nine closest relatives. The genome-based G+C content of genomic DNA was 44.4%.

The predominant metabolic end products of glucose fermentation were acetate and succinate.

Based on these data, we propose that strain WCA-9-b2 represents a novel species within a novel genus, for which the name Sporaefaciens musculi gen. nov., sp. nov. is proposed. The type strain is WCA-9-b2T (=DSM 106039T = CCUG pending IDT).

Authors: Torben Sølbeck Rasmussen, Theresa Streidl, Thomas C.A. Hitch, Esther Wortmann, Paulina Deptula, Michael Hansen, Dennis Sandris Nielsen, Thomas Clavel, Finn Kvist Vogensen