brachybacterium muris brachybacterium muris brachybacterium muris is a species of gram positive, strictly aerobic, yellow-pigmented bacterium. the cells are coccoid during the stationary phase, and irregular rods during the exponential phase. it was first isolated from the liver of a laboratory mouse. the species was first described in 2003, and the name is derived from the latin muris (mouse). brachybacterium muris scientific classification domain: bacteria phylum: actinomycetota class: actinomycetia order: micrococcales family: dermabacteraceae genus: brachybacterium species: b. muris binomial name brachybacterium murisbuczolits et al. 2003 the optimum growth temperature for b. muris is 25-37 °c. it can grow in the 15-42 °c range and in ph 6.0-9.0.