Bacillus
This article is about a genus of rod-shaped bacteria. For the genus of rod-shaped ghost insects, see Bacillus (genus of insect); for other meanings, see Bacillus.
Bacillus (Latin for "rod") is the name of a genus of rod-shaped bacteria with more than 200 known species. They are gram-positive, endospore-forming, aerobic and can usually move actively by means of peritrichous flagella. Characteristic of the genus Bacillus, which occurs predominantly in soil, is the formation of endospores and (in contrast to the genus Clostridium) aerobic or facultatively aerobic growth and aerobic energy metabolism. Some species of these bacteria, which are widespread in the environment and largely non-pathogenic, can be pathogenic (disease-causing), causing, for example, toxin-induced enteritis from food (Bacillus cereus enteritis), catheter-associated infections, (post-traumatic) endophthalmitis, rarely bacteraemia and sepsis.
Colloquially, various pathogenic microorganisms such as bacteria, amoebae and viruses are called bacillus or bacillus. However, the organisms so designated do not form a biological systematic group (taxon) and the vast majority of them do not belong to the genus Bacillus.
Properties
They multiply only under aerobic conditions, even on simple basic culture media. All species produce lecithinase and catalase, most species differ in the utilization of carbohydrates and the ability to actively move. For the decomposition of biotic tissues they possess a wide range of species-specific enzymes (ex: collagenases, proteases). Some representatives of the genus form toxins (e.g. haemolysins).
The GC content of their DNA is very inconsistent. It ranges from 32 to 69%.
As a special feature, many species of the genus Bacillus contain a high to predominant proportion of branched fatty acid chains in their membranes.
Penicillins, cephalosporins, ciprofloxacin, levofloxacin, vancomycin and clindamycin can be used for antibiotic therapy of a Bacillus infection.
Forms of the cells with spores
1. spore central
2. spore terminal with inclusion body (protein)
3. spore terminal, bacterium club-shaped distended
4. spore central, bacterium spindle-shaped distended ("Clostridium form")
5. spore terminal, round = Plectridium
6. spore lateral, bacterium spindle-shaped distended.
Questions and Answers
Q: What is Bacillus?
A: Bacillus is a genus of rod shaped bacteria.
Q: Are Bacilli Gram-positive?
A: Yes, they are Gram-positive, meaning they have an extra outside cell layer.
Q: How do Bacilli respire?
A: They do aerobic respiration.
Q: Where can we find them in nature?
A: They are everywhere in nature.
Q: What happens when the environment becomes stressful for Bacilli?
A: Under stressful conditions, they produce endospores which can stay in a dormant state for long periods.
Q: What species of Bacillus are worth noting? A: Notable species of Bacillus include Bacillus anthracis (which causes Anthrax), Bacillus subtilis (considered an model organism often used in genetic engineering), Bacillus cereus (responsible for a form of food poisoning) andBacillus thuringensis (used in pest control to produce toxins which can kill some moths and certain butterflies).
