Bacillus anthracis, the bacterium that causes the deadly disease anthrax produces thick endospores.
what is the significant role of spore formation in the reproductive cycle of this bacterium?

An endospore is a stripped-down, dormant form to which the bacterium can reduce itself. Endospore formation is usually triggered by a lack of nutrients, and usually occurs in gram-positive bacteria. [ [ In endospore formation, the bacterium divides within its cell wall. One side then engulfs the other. Endospores enable bacteria to lay dormant for extended periods, even centuries.