Bacillus n. : A variety of bacterium; a microscopic, rod-shaped vegetable organism.

Example:
How can one tell the difference between Bacillus cereus and Bacillus megaterium using physiological testing?

Taxonomy
Bacillus, Bacillus species, cell wall, resistant, genus, free encyclopedia, species, bacterium, rod-shaped, Bacillus subtilis, model organism, Gram positive bacteria, bacterial genus, cells, oval, enzymes, molecular biology, food.

Defination from the web:
Bacillus is a genus of rod-shaped bacteria and a member of the division Firmicutes. ... Many Bacillus species are able to secrete large quantities of enzymes. ... Bacillus subtilis is one of the best understood prokaryotes, in terms of molecular biology and cell biology. ...