What does the capsule of a bacterial cell do?

The capsule of a bacterial cell provides a protective gel-like layer that serves several important functions. This outer layer is primarily composed of polysaccharides, making it sticky and enabling bacteria to adhere to surfaces and form biofilms. The capsule plays a crucial role in the defense against the immune response of host organisms, as it can inhibit phagocytosis by white blood cells. Additionally, the capsule helps in retaining moisture, which is essential for bacterial survival in harsh environments. By having this protective layer, bacteria are more resilient and can better colonize their environments, which contributes to their overall fitness and virulence.