Identification and Characterization of Two Novel Members of the Family Eubacteriaceae, Anaerofustis butyriciformans sp. nov. and Pseudoramibacter faecis sp. nov., Isolated from Human Feces.

Members of Eubacteriaceae are involved in host health and diseases. Two Gram-stain-positive, strictly anaerobic, non-motile, non-spore-forming, and rod-shaped bacterial strains, HA2171(T) and HA2172(T), were isolated from the feces of Chinese healthy donors. Based on 16S rRNA gene sequences, HA2171(T) and HA2172(T) belonged to the family Eubacteriaceae. Physiological and biochemical characterizations indicated that HA2171(T) and HA2172(T) were neutrophilic, mesophilic, and tolerant to low-concentration NaCl. The major cellular fatty acids (>10.0%) of HA2171(T) were C(16:0), C(14:0), C(18:1ω7c), and C(17:0) 2-OH, and those of HA2172(T) were C(14:0) and C(16:0). MK-6 was the respiratory quinone in both strains. Phylogenetic and phylogenomic analyses showed that HA2171(T) was closest to Anaerofustis stercorihominis ATCC BAA-858(T) and that HA2172(T) as closest to Pseudoramibacter alactolyticus ATCC 23263(T). Genome annotation revealed that the HA2171(T) and HA2172(T) were able to metabolize carbohydrates and produce acetate and butyrate. HA2172(T) contains genes associated with hydrogen sulfide production, which is a potential risk for diseases. Based on the phylogenetic, phenotypic, and chemotaxonomic characteristics, we propose that HA2171(T) and HA2172(T) represent two novel species, and the names Anaerofustis butyriciformans sp. nov. and Pseudoramibacter faecis sp. nov. are proposed.