Bacillus anthracis is a Gram-positive spore-forming, rod-shaped
bacterium, with a width of 1-1.2µm and a length of 3-5µm. It can
be grown in an ordinary nutrient medium under aerobic or
anaerobic conditions. It is the only bacterium known to
synthesize a protein capsule (D-glutamate), and the only
pathogenic bacterium to carry its own adenylyl cyclase virulence
factor (edema factor). It bears close genotypical and
phenotypical resemblance to Bacillus cereus and Bacillus
thuringiensis. All three species share cellular dimensions and
morphology. All form oval spores located centrally in a non-
swollen sporangium. Bacillus anthracis spores in particular are
highly resilient, surviving extremes of temperature, low-
nutrient environments, and harsh chemical treatment over decades
or centuries. Casimir Davaine demonstrated that the symptoms of
anthrax were invariably accompanied by the microbe B. anthracis.
Aloys Pollender is also credited for this discovery. B.
anthracis was the first bacterium conclusively demonstr