Bacillus subtilis, Gram stained
Bacillus is a genus of rod-shaped, beta-hemolytic Gram-positive bacteria and a member of the division Firmicutes. A genus (plural genera from Γένος Latin genus "descent family type gender" is a low-level Taxonomic Gram-positive bacteria are those that are stained dark blue or violet by Gram staining. The Bacteria ( singular: bacterium) are a large group of unicellular Microorganisms Typically a few Micrometres in length bacteria have The Firmicutes ( Latin: firmus, strong and cutis, skin referring to the cell wall are a division of bacteria, most of which have Gram-positive Bacillus species are either obligate or facultative aerobes, and test positive for the enzyme catalase. An aerobic organism or aerobe is an Organism that has an Oxygen based Metabolism. Enzymes are Biomolecules that catalyze ( ie increase the rates of Chemical reactions Almost all enzymes are Proteins Catalase is a common Enzyme found in nearly all living organisms where it functions to catalyze the decomposition of Hydrogen peroxide to  Ubiquitous in nature, Bacillus includes both free-living and pathogenic species. Under stressful environmental conditions, the cells produce oval endospores that can stay dormant for extended periods. An endospore is a dormant, tough and non-reproductive structure produced by a small number of Bacteria from the Firmicute phylum These characteristics originally defined the genus, but not all such species are closely related, and many have been moved to other genera. 
Bacillus subtilis is one of the best understood prokaryotes in terms of molecular biology and cell biology. Bacillus subtilis Sporejpg|thumb|right|Sporulating Bacillus subtilis ]] Bacillus subtilis is a Gram-positive, Catalase -positive Its superb genetic amenability and relatively large size have provided the powerful tools required to investigate a bacterium from all possible aspects. Recent improvements in fluorescence microscopy techniques have provided novel and amazing insight into the dynamic structure of a single cell organism. Research on Bacillus subtilis has been at the forefront of bacterial molecular biology and cytology, and the organism is a model for differentiation, gene/protein regulation, and cell cycle events in bacteria. Bacillus subtilis Sporejpg|thumb|right|Sporulating Bacillus subtilis ]] Bacillus subtilis is a Gram-positive, Catalase -positive 
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. Bacillus anthracis is a Gram-positive, facultatively anaerobic, rod-shaped Bacterium of the genus Bacillus. Anthrax is an acute Disease in humans and animals caused by the bacterium Bacillus anthracis which is highly lethal in some forms Bacillus cereus is an endemic, soil-dwelling Gram-positive, rod-shaped, beta hemolytic bacteria that causes Foodborne Foodborne illness (also foodborne disease) is any Illness resulting from the consumption of food Staphylococcus (in Greek σταφυλη staphyle means bunch of grapes and κοκκος coccos means granule is a genus of Gram-positive  A third species, B. thuringiensis, is an important insect pathogen, and is sometimes used to control insect pests. Bacillus thuringiensis is a Gram-positive, soil dwelling Bacterium of the Genus Bacillus. Insects ( Class Insecta) are a major group of Arthropods and the most diverse group of Animals on the Earth with over a million described The type species is B. subtilis, an important model organism. In Taxonomy, a type species is the species that originally defined a genus. Bacillus subtilis Sporejpg|thumb|right|Sporulating Bacillus subtilis ]] Bacillus subtilis is a Gram-positive, Catalase -positive A model organism is a Species that is extensively studied to understand particular biological Phenomena, with the expectation that discoveries made It is also a notable food spoiler, causing ropiness in bread and related food. B. coagulans is also important in food spoilage. Bacillus coagulans is a Lactic acid forming bacterial species within the genus Bacillus.
An easy way to isolate Bacillus is by placing non-sterile soil in a test tube with water, shaking, placing in melted Mannitol Salt Agar, and incubating at room temperature for at least a day. A test tube, also known as a culture tube, sample tube, test flute or flaccid flute, is a piece of Laboratory glassware composed of Colonies are usually large, spreading and irregularly-shaped. Under the microscope, the Bacillus appear as rods, and a substantial portion usually contain an oval endospore at one end, making it bulge. An endospore is a dormant, tough and non-reproductive structure produced by a small number of Bacteria from the Firmicute phylum
The cell wall of Bacillus is a structure on the outside of the cell that forms the second barrier between the bacterium and the environment, and at the same time maintains triangle shape and withstands the pressure generated by the cell's turgor. The cell wall is composed of salt, 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. The role of the cytoskeleton in shape generation and maintenance is important .
Although Bacillus, capitalized and italicized, specifically refers to the genus, the word 'bacillus' may also be used to describe any rod-shaped bacterium, and in this sense, bacilli are found in many different taxonomic groups of bacteria. In Typography, italic type /ɪˈtælɪk/ or /aɪˈtælɪk/ refers to cursive Typefaces based on a stylized form of calligraphic Handwriting.
Likewise, Bacilli refers to the particular class Bacillus belongs to, while bacilli are any rod-shaped bacteria. Bacilli specifically refers to a taxonomic class of Bacteria.
It should be noted that the cell morphology term bacillus does not necessarily indicate Gram-positive staining, as E. coli is a Gram-negative, rod-shaped bacteria. Gram-positive bacteria are those that are stained dark blue or violet by Gram staining. Gram-negative bacteria are those Bacteria that do not retain Crystal violet dye in the Gram staining protocol