bacillus species; the power points
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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.