brachybacterium tyrofermentans brachybacterium tyrofermentans brachybacterium tyrofermentans is a species of gram positive, facultatively anaerobic, pale yellow-pigmented bacterium. the cells are coccoid during the stationary phase, and irregular rods during the exponential phase. it was first isolated from the surfaces of beaufort and gruyère cheeses in 1978, along with brachybacterium alimentarium. further work led to the proposal of the new species in 1996, and the name is derived from the latin tyros (cheese) and fermentans (leavening), referring to the fermented cheese from which it was first isolated. brachybacterium tyrofermentans scientific classification domain: bacteria phylum: actinomycetota class: actinomycetia order: micrococcales family: dermabacteraceae genus: brachybacterium species: b. tyrofermentans binomial name brachybacterium tyrofermentansschubert et al. 1996 the optimum growth temperature for b. tyrofermentans is 30 °c, but can grow in the 20-37 °c range. the optimum ph is 7.3.