Bacillus subtilis - spore forming, rod prokaryote (bacterium)
Copyright 2007 Dennis Kunkel Microscopy, Inc.
Caption: Bacillus subtilis - Gram-positive, aerobic, spore forming, rod prokaryote. Bacillus subtilis is commonly found in soil and decaying organic matter. During nutrient deficiency or adverse environmental conditions it can form endospores / spores (resting cells, seen here as bulbous rods). These spores have a very thick cell wall and can survive for long periods of time being resistant to heat, acid and salt. They may germinate under favorable conditions to form the vegetative, rod shaped cells (bacilli). B. subtilis is not considered a human pathogen but it sometimes is pathogenic, causing severe eye infections such as iridocyclitis and panopthalmitis. Several strains related to B. subtilis are used in the commercial production of extracellular enzymes. Other strains produce insect toxins, peptide antibiotics and antifungals, some of which have been used in agricultural crop protection. B. subtilis has can be genetically manipulated, and has become widely used as a model organism for laboratory studies. It also produces the proteolytic enzyme called subtilisin which has been shown to be a potential cure for certain types of cancer. Magnification*: x2,400 Type: SEM
*(Magnifications are based on a 35mm slide image of 24mm in the narrow dimension.)