What is the main component of the capsule produced by Bacillus anthracis?

The capsule produced by Bacillus anthracis is primarily composed of a polypeptide known as poly-D-glutamic acid. This unique feature is significant because it differentiates B. anthracis from many other bacteria that typically produce polysaccharide capsules. The polypeptide capsule serves as a virulence factor, aiding the bacterium in evading the host's immune system by inhibiting phagocytosis. This ability to avoid immune detection is crucial for the survival and pathogenicity of B. anthracis, making the polypeptide composition of its capsule an essential characteristic in understanding its role as a pathogen.

In summary, Bacillus anthracis produces a polypeptide capsule, specifically composed of poly-D-glutamic acid, which is integral to its virulence.