Bacillus is a genus of Gram-positive,
rod-shaped bacteria and a member of the division Firmicutes.
Bacillus species can be obligate aerobes or facultative anaerobes, and test positive for the enzyme catalase.
Under stressful environmental conditions, the cells produce oval endospores that can stay dormant for extended periods.
Two Bacillus species are considered medically significant: B. anthracis, which causes anthrax, and B. cereus, which causes a foodborne illness similar to that of Staphylococcus. A third species, B. thuringiensis, is an important insect pathogen, and is sometimes used to control insect pests. The type species is B. subtilis, an important model organism. It is also a notable food spoiler, causing ropiness in bread and related food. Some environmental and commercial strains B. coagulans may play a role in food spoilage of highly acidic, tomato based products.
The cell wall is composed of teichoic and teichuronic acids. B. subtilis is the first bacterium for which the role of an actin-like cytoskeleton in cell shape determination and peptidoglycan synthesis was identified, and for which the entire set of peptidoglycan-synthesizing enzymes was localised.
coccobacillas-shape between the two
Chain = Streptobacillus