Bacillus

Bacillus

Bacillus is a genus of Gram-positive, rod-shaped (bacillus),bacteria and a member of the phylum Firmicutes. Bacillusspecies can be obligate aerobes (oxygen reliant), orfacultative anaerobes (having the ability to be aerobic or anaerobic). They will test positive for the enzymecatalase when there has been oxygen used or present.Ubiquitous in nature, Bacillusincludes both free-living (non-parasitic) and parasiticpathogenic species. Under stressful environmental conditions, the bacteria can produce oval endospores that are not true spores but which the bacteria can reduce themselves to and remain in a dormant state for very long periods. These characteristics originally defined the genus, but not all such species are closely related, and many have been moved to other genera of Firmicutes.

Many species of Bacillus can produce copious amounts of enzymes which are made use of in different industries. SomeBacillus species can form intracellular inclusions of polyhydroxyalkanoates under certain adverse environmental conditions, as in a lack of elements such as phosphorus, nitrogen, or oxygen combined with an excessive supply of carbon sources.

B.subtilis has proved a valuable model for research. Other species of Bacillus are important pathogens, causing anthrax and food poisoning.

Clinical significance

Two Bacillus species are considered medically significant: B. anthracis, which causes anthrax, and B. cereus, which causes food poisoning similar to that caused by 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 of B. coagulans may play a role in food spoilage of highly acidic, tomato-based products.

Isolation

An easy way to isolate Bacillus is by placing nonsterile soil in a test tube with water, shaking, placing in melted mannitol salt agar, and incubating at room temperature for at least a day. Colonies are usually large, spreading, and irregularly shaped. Under the microscope, the Bacillus cells appear as rods, and a substantial portion of the cells usually contain oval endospores at one end, making it bulge

Sphingomonas paucimobilis

Sphingomonas paucimobilis (able to degrade lignin-related biphenyl chemical compounds) is an aerobic Gram-negative soil bacillus that has a single polarflagellum with slow motility. The cell size is around 0.7 x 1.4 μm.As with the other members of the genus, its biochemistry is remarkable in possession of ubiquinone 10 as its major respiratory quinone, and of glycosphingolipids instead of lipopolysaccharides in its cell envelope. It has been implicated in various types of clinical infection.,