Sporulating Bacteria

bacteria that form a single spore (endospore) within the cell. Sporulating bacteria are usually rodshaped and are called bacilli. Spore formation does not occur in young bacteria but begins in older cells; however, spores are not an obligatory stage in the life cycle of bacilli. Under favorable nutrient conditions, sporulating bacteria may reproduce by fission as vegetative cells over a long period of time, and sporulation begins only under specific conditions. Sporulating bacteria are widely distributed in soil, water, and air. Aerobic sporulating bacteria include the hay bacillus (Bacillus subtilis) and Bacillusmesentericus. Anaerobic forms include Clostridium, the causative agent of tetanus.