General characteristics Rod shape Gram positive; some

species cultures turn Gram-negative with age

Obligate aerobes but some are facultative anaerobes

Test positive for catalase test

Produce endospores under stressful condition

Free living non-pathogenic and pathogenic Bacillus

· Habitat • Ubiquitous: found in soil, water, air and in

extremes environments of high PH and temperature

Bacillus acidophilus – acidic environment Bacillus thermophiles –high temp.Isolation: • Heat soil sample in water upto 800c and plate on

specific mediaDistribution: Ubiquitous Hosts:Animal host; Man (Bacillus anthracis), Insects (Bacillus thuringiensis).Plant hosts: WBW, B. megaterium, B. circulans in date palm tissue culture, B. polymyxa in tomato seedling blight.

Life style Bacillus can degrade substrates from both plants and animals

including cellulose, starch, pectin, proteins, and hydrocarbons. Antibiotics producers Heterotrophic nitrifiers, denitrifiers and nitrogen fixers Are iron precipitators; selenium oxidixers Oxidize and reduce manganese Chemolithotrophs Acidophiles, alkalophiles, psychrophiles and thermophiles Cause food poisoning and food spoilage

Some important Bacillus Bacillus anthracis; causes anthrax in human Bacillus cereus: causes food poisoning Bacillus thuringiensis: (carry Bt toxin) insect pathogen Bacillus subtilis: important research model organism both in cell

and molecular biology

History The first described Bacillus was named Vibrio

subtilis in 1835 by Christian Gottfried Ehrenberg

In 1872, Ferdinand Cohn renamed the organism as Bacillus subtilis after its ability to produce endospores which are round, oval or cylindrical

Cohn and Koch made the early discoveries about spores resistant to heat and the development cycle of sporeformers, working with B. subtilis and anthracis respectively.

BACILLUS SPECIES: AEROBIC ENDOSPORE FORMING GRAM POSITIVE BACTERIA BY RUFUS AKINRINLOLA GRAD STUDENT ,UNL

ReproductionAsexual reproduction; binary fission; mitosis

Classification and Phylogeny

Classification methods Physiological classification DNA bases (G+C content) and DNA-DNA

hybridization 16s rRNAReference

Slepecky, R. A., & Hemphill, H. E. (2006). The genus Bacillus—nonmedical. InThe prokaryotes (pp. 530-562). Springer US.