Bacillaceae /bas′əlā″si·ē/ [L, bacillum, small rod] , a family of Bacilli of the order Bacillales, consisting of gram-positive, rod-shaped cells that can produce cylindric, ellipsoid, or spheric endospores situated terminally, subterminally, or centrally. These cells are chemoheterotrophic and mostly saprophytic, commonly appearing in soil. Some are parasitic on insects and animals and are pathogenic. The family includes the genus Bacillus, which is aerobic, and the genus Clostridium, which is facultatively anaerobic.
