Bacillus anthracis can be differentiated from Bacillus cereus by which of the following tests?

Bacillus anthracis, the causative agent of anthrax, can be distinguished from Bacillus cereus through various biochemical tests. The key differentiating factor is the ability of Bacillus anthracis to produce a lecithinase enzyme, which is involved in breaking down phospholipids. This characteristic leads to the formation of a characteristic zone of opacity in egg yolk agar.

While both Bacillus species can be observed on a blood agar plate, the correct differentiation between them primarily involves testing for lecithinase production rather than motility or beta-hemolysis patterns. Bacillus anthracis is non-motile and typically does not exhibit beta-hemolysis, whereas Bacillus cereus can be motile and is often beta-hemolytic.

In testing scenarios, using lecithinase activity provides a clear distinction, with Bacillus anthracis showing positive results for this specific enzyme activity. This test is more definitive for differentiation than motility or hemolytic activity, making it crucial for accurate identification in clinical microbiology.