Scanning electron micrograph of F. prausnitzii strain A2165. Bar, 1 µm. - Source:2Fermentation
Strains belonging to the sole species of the genus Faecalibacterium are strictly anaerobic bacteria, with a fermentative type of metabolism. Butyrate, D-lactate and formate are products of glucose fermentation. Acetate is utilized by all strains. Strains Fusobacterium prausnitzii ATCC 27768T and 27766, A2-165 and L2-6 are able to hydrolyze fructose, fructose-oligosaccharides, starch and inulin. In pure culture, cells appear as straight rods. No physiological information has been determined for the genus in situ in activated sludge.
 Duncan, Hold, Harmsen, Stewart, Flint - Growth requirements and fermentation products of Fusobacterium prausnitzii, and a proposal to reclassify it as Faecalibacterium prausnitzii gen. nov., comb. nov. - Int. J. Syst. Evol. Microbiol. 52(Pt 6): 2141-6. doi:10.1099/00207713-52-6-2141