brachybacterium faecium brachybacterium faecium brachybacterium faecium is a species of gram positive, facultatively anaerobic bacterium. colony pigmentation is grey, white, or pale yellow. the cells are coccoid during the stationary phase, and irregular rods during the exponential phase. it was first isolated from poultry deep litter in 1966. the species was the first proposed for genus brachybacterium in 1988, and is the type strain for the genus. the name is derived from the latin faecium (dregs of feces), referring to the poultry litter from which it was first isolated. brachybacterium faecium scientific classification domain: bacteria phylum: actinomycetota class: actinomycetia order: micrococcales family: dermabacteraceae genus: brachybacterium species: b. faecium binomial name brachybacterium faeciumcollins et al. 1988 the optimum growth temperature for b. faecium is 25-30 °c.