Clostridium
Encyclopedia
Clostridium is a genus
of Gram-positive
bacteria, belonging to the Firmicutes
. They are obligate anaerobe
s capable of producing endospore
s. Individual cells are rod-shaped, which gives them their name, from the Greek kloster (κλωστήρ) or spindle. These characteristics traditionally defined the genus, however many species originally classified as Clostridium have been reclassified in other genera.
that include common free-living bacteria as well as important pathogen
s. There are four main species responsible for disease
in humans:
Clostridium is sometimes found in raw swiftlet
nests, a Chinese delicacy. Nests are washed in a sulfite solution to kill the bacteria before being exported to the U.S.
Neurotoxin
production is the unifying feature of the species C. botulinum. Seven types of toxins have been identified and allocated a letter (A-G). Most strains produce one type of neurotoxin but strains producing multiple toxins have been described. C. botulinum producing B and F toxin types have been isolated from human botulism cases in New Mexico and California. The toxin type has been designated Bf as the type B toxin was found in excess of the type F. Similarly, strains producing Ab and Af toxins have been reported.
Organisms genetically identified as other Clostridium species have caused human botulism; Clostridium butyricum
producing type E toxin and Clostridium baratii
producing type F toxin. The ability of C. botulinum to naturally transfer neurotoxin genes to other Clostridium species is concerning, especially in the food industry where preservation systems are designed to destroy or inhibit only C. botulinum but not other Clostridium species.
can utilize lignocellulosic waste and generate ethanol, thus making it a possible candidate for use in production of ethanol fuel
. It also has no oxygen requirement and is thermophilic
, which reduces cooling cost.
C. acetobutylicum
, also known as the Weizmann organism, was first used by Chaim Weizmann
to produce acetone
and biobutanol from starch
in 1916 for the production of gunpowder
and TNT.
C. botulinum
produces a potentially lethal neurotoxin that is used in a diluted form in the drug Botox, which is carefully injected to nerves in the face, which prevents the movement of the expressive muscles of the forehead, to delay the wrinkling effect of ageing. It is also used to treat spasmodic torticollis
and provides relief for approximately 12 to 16 weeks.
The anaerobic bacterium
C. ljungdahlii
, recently discovered in commercial chicken wastes, can produce ethanol from single-carbon sources including synthesis gas, a mixture of carbon monoxide
and hydrogen
that can be generated from the partial combustion
of either fossil fuel
s or biomass
. Use of these bacteria to produce ethanol from synthesis gas has progressed to the pilot plant stage at the BRI Energy facility in Fayetteville, Arkansas
.
Fatty acid
s are converted by yeast
s to long-chain dicarboxylic acid
s and then to 1,3-propanediol
using Clostridium diolis.
Genes from C. thermocellum
have been inserted into transgenic mice to allow the production of endoglucanase. The experiment was intended to learn more about how the digestive capacity of monogastric
animals could be improved. Hall et al. published their findings in 1993.
Non-pathogenic strains of Clostridium may help in the treatment of diseases such as cancer
. Research shows that Clostridium can selectively target cancer cells. Some strains can enter and replicate within solid tumours
. Clostridium could, therefore, be used to deliver therapeutic proteins to tumours. This use of Clostridium has been demonstrated in a variety of preclinical models.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of Gram-positive
Gram-positive
Gram-positive bacteria are those that are stained dark blue or violet by Gram staining. This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain and appearing red or pink...
bacteria, belonging to the Firmicutes
Firmicutes
The Firmicutes are a phylum of bacteria, most of which have Gram-positive cell wall structure. A few, however, such as Megasphaera, Pectinatus, Selenomonas and Zymophilus, have a porous pseudo-outer-membrane that causes them to stain Gram-negative...
. They are obligate anaerobe
Obligate anaerobe
Obligate anaerobes are microorganisms that live and grow in the absence of molecular oxygen; some of these are killed by oxygen. -Metabolism:...
s capable of producing endospore
Endospore
An endospore is a dormant, tough, and temporarily non-reproductive structure produced by certain bacteria from the Firmicute phylum. The name "endospore" is suggestive of a spore or seed-like form , but it is not a true spore . It is a stripped-down, dormant form to which the bacterium can reduce...
s. Individual cells are rod-shaped, which gives them their name, from the Greek kloster (κλωστήρ) or spindle. These characteristics traditionally defined the genus, however many species originally classified as Clostridium have been reclassified in other genera.
Overview
Clostridium consists of around 100 speciesthat include common free-living bacteria as well as important pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
s. There are four main species responsible for disease
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
in humans:
- C. botulinumClostridium botulinumClostridium botulinum is a Gram-positive, rod-shaped bacterium that produces several toxins. The best known are its neurotoxins, subdivided in types A-G, that cause the flaccid muscular paralysis seen in botulism. It is also the main paralytic agent in botox. C. botulinum is an anaerobic...
, an organism that produces botulinum toxinBotulinum toxinBotulinum toxin is a protein produced by the bacterium Clostridium botulinum, and is considered the most powerful neurotoxin ever discovered. Botulinum toxin causes Botulism poisoning, a serious and life-threatening illness in humans and animals...
in food/wound and can cause botulismBotulismBotulism also known as botulinus intoxication is a rare but serious paralytic illness caused by botulinum toxin which is metabolic waste produced under anaerobic conditions by the bacterium Clostridium botulinum, and affecting a wide range of mammals, birds and fish...
. HoneyHoneyHoney is a sweet food made by bees using nectar from flowers. The variety produced by honey bees is the one most commonly referred to and is the type of honey collected by beekeepers and consumed by humans...
sometimes contains spores of Clostridium botulinum, which may cause infant botulism in humans one year old and younger. The toxin eventually paralyzes the infant's breathing muscles. Adults and older children can eat honey safely, because Clostridium do not compete well with the other rapidly growing bacteria present in the gastrointestinal tract. This same toxin is known as "Botox" and is used cosmetically to paralyze facial muscles to reduce the signs of aging; it also has numerous therapeutic uses.
- C. difficileClostridium difficileClostridium difficile , also known as "CDF/cdf", or "C...
, which can flourish when other bacteria in the gutGut floraGut flora consists of microorganisms that live in the digestive tracts of animals and is the largest reservoir of human flora. In this context, gut is synonymous with intestinal, and flora with microbiota and microflora....
are killed during antibioticAntibioticAn antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
therapy, leading to pseudomembranous colitisPseudomembranous colitisPseudomembranous colitis, a cause of antibiotic-associated diarrhea , is an infection of the colon. It is often, but not always, caused by the bacterium Clostridium difficile. Because of this, the informal name C. difficile colitis is also commonly used. The illness is characterized by...
(a cause of antibiotic-associated diarrhea).
- C. perfringensClostridium perfringensClostridium perfringens is a Gram-positive, rod-shaped, anaerobic, spore-forming bacterium of the genus Clostridium. C. perfringens is ever present in nature and can be found as a normal component of decaying vegetation, marine sediment, the intestinal tract of humans and other vertebrates,...
, formerly called C. welchii, causes a wide range of symptoms, from food poisoningFoodborne illnessFoodborne illness is any illness resulting from the consumption of contaminated food, pathogenic bacteria, viruses, or parasites that contaminate food, as well as chemical or natural toxins such as poisonous mushrooms.-Causes:Foodborne illness usually arises from improper handling, preparation, or...
to gas gangreneGas gangreneGas gangrene is a bacterial infection that produces gas tissues in gangrene. It is a deadly form of gangrene usually caused by Clostridium perfringens bacteria. It is a medical emergency....
. Also responsible for enterotoxemiaEnterotoxemiaEnterotoxemia is an infection by Clostridium perfringens which affects several types of domesticated animals, but is not known to affect humans. It is also known as overeating disease and can kill the animals within 2 hours.-External links:...
(also known as "overeating disease" or "pulpy kidney disease") in sheep and goats. C. perfringens also takes the place of yeastYeastYeasts are eukaryotic micro-organisms classified in the kingdom Fungi, with 1,500 species currently described estimated to be only 1% of all fungal species. Most reproduce asexually by mitosis, and many do so by an asymmetric division process called budding...
in the making of salt rising breadSalt rising breadSalt rising bread is bread in which the main rising agent is a bacterium Clostridium perfringens, which leavens the bread along with lactobacillus and other wild microbes, as opposed to mainly yeast or baking soda. It is thought that the salt used in the starter is used to suppress yeast growth...
. The name perfringens means 'breaking through' or 'breaking in pieces'.
- C. tetaniClostridium tetaniClostridium tetani is a rod-shaped, anaerobic bacterium of the genus Clostridium. Like other Clostridium species, it is Gram-positive, and its appearance on a gram stain resembles tennis rackets or drumsticks. C. tetani is found as spores in soil or in the gastrointestinal tract of animals. C...
, the causative organism of tetanusTetanusTetanus is a medical condition characterized by a prolonged contraction of skeletal muscle fibers. The primary symptoms are caused by tetanospasmin, a neurotoxin produced by the Gram-positive, rod-shaped, obligate anaerobic bacterium Clostridium tetani...
. The name derives from "of a tension", referring to the tension (caused by tetanus) in the muscles.
- C. sordelliiClostridium sordelliiClostridium sordellii is a rare anaerobic, gram-positive, spore forming rod with peritrichous flagella that is capable of causing pneumonia, endocarditis, arthritis, peritonitis, and myonecrosis. C. sordellii bacteremia and sepsis occur rarely. Most cases of sepsis from C. sordellii occur in...
has been linked to the deaths of more than a dozen women after childbirth.Fatal Clostridium sordellii infections after medical abortions.Meites E, Zane S, Gould C; N Engl J Med. 2010 Sep 30;363(14):1382-3.
Clostridium is sometimes found in raw swiftlet
Swiftlet
Swiftlets are birds contained within the four genera Aerodramus, Hydrochous, Schoutedenapus and Collocalia. They form the Collocaliini tribe within the swift family Apodidae. The group contains around thirty species mostly confined to southern Asia, south Pacific islands, and northeastern...
nests, a Chinese delicacy. Nests are washed in a sulfite solution to kill the bacteria before being exported to the U.S.
Neurotoxin
Neurotoxin
A neurotoxin is a toxin that acts specifically on nerve cells , usually by interacting with membrane proteins such as ion channels. Some sources are more general, and define the effect of neurotoxins as occurring at nerve tissue...
production is the unifying feature of the species C. botulinum. Seven types of toxins have been identified and allocated a letter (A-G). Most strains produce one type of neurotoxin but strains producing multiple toxins have been described. C. botulinum producing B and F toxin types have been isolated from human botulism cases in New Mexico and California. The toxin type has been designated Bf as the type B toxin was found in excess of the type F. Similarly, strains producing Ab and Af toxins have been reported.
Organisms genetically identified as other Clostridium species have caused human botulism; Clostridium butyricum
Clostridium butyricum
Clostridium butyricum is an anaerobic prokaryote that requires the absolute absence of oxygen to grow. It produces butyric acid which is an indicator of the presence of saccharolytic clostridia. It is an endospore-former and can live under rough conditions...
producing type E toxin and Clostridium baratii
Clostridium baratii
Clostridium baratii is an anaerobic, motile, gram-positive bacterium....
producing type F toxin. The ability of C. botulinum to naturally transfer neurotoxin genes to other Clostridium species is concerning, especially in the food industry where preservation systems are designed to destroy or inhibit only C. botulinum but not other Clostridium species.
Commercial uses
C. thermocellumClostridium thermocellum
Clostridium thermocellum is an anaerobic, thermophilic bacterium. C. thermocellum has garnered research interest due to its cellulolytic and ethanologenic abilities, being capable of directly converting a cellulosic substrate into ethanol. This makes it useful in converting biomass into a usable...
can utilize lignocellulosic waste and generate ethanol, thus making it a possible candidate for use in production of ethanol fuel
Ethanol fuel
Ethanol fuel is ethanol , the same type of alcohol found in alcoholic beverages. It is most often used as a motor fuel, mainly as a biofuel additive for gasoline. World ethanol production for transport fuel tripled between 2000 and 2007 from 17 billion to more than 52 billion litres...
. It also has no oxygen requirement and is thermophilic
Thermophile
A thermophile is an organism — a type of extremophile — that thrives at relatively high temperatures, between 45 and 122 °C . Many thermophiles are archaea...
, which reduces cooling cost.
C. acetobutylicum
Clostridium acetobutylicum
Clostridium acetobutylicum, ATCC 824, is included in the genus Clostridium, is a commercially valuable bacterium sometimes called the "Weizmann Organism", after Jewish-Russian born Chaim Weizmann, then senior lecturer at the University of Manchester, England, used them in 1916 as a bio-chemical...
, also known as the Weizmann organism, was first used by Chaim Weizmann
Chaim Weizmann
Chaim Azriel Weizmann, , was a Zionist leader, President of the Zionist Organization, and the first President of the State of Israel. He was elected on 1 February 1949, and served until his death in 1952....
to produce acetone
Acetone
Acetone is the organic compound with the formula 2CO, a colorless, mobile, flammable liquid, the simplest example of the ketones.Acetone is miscible with water and serves as an important solvent in its own right, typically as the solvent of choice for cleaning purposes in the laboratory...
and biobutanol from starch
Starch
Starch or amylum is a carbohydrate consisting of a large number of glucose units joined together by glycosidic bonds. This polysaccharide is produced by all green plants as an energy store...
in 1916 for the production of gunpowder
Gunpowder
Gunpowder, also known since in the late 19th century as black powder, was the first chemical explosive and the only one known until the mid 1800s. It is a mixture of sulfur, charcoal, and potassium nitrate - with the sulfur and charcoal acting as fuels, while the saltpeter works as an oxidizer...
and TNT.
C. botulinum
Clostridium botulinum
Clostridium botulinum is a Gram-positive, rod-shaped bacterium that produces several toxins. The best known are its neurotoxins, subdivided in types A-G, that cause the flaccid muscular paralysis seen in botulism. It is also the main paralytic agent in botox. C. botulinum is an anaerobic...
produces a potentially lethal neurotoxin that is used in a diluted form in the drug Botox, which is carefully injected to nerves in the face, which prevents the movement of the expressive muscles of the forehead, to delay the wrinkling effect of ageing. It is also used to treat spasmodic torticollis
Spasmodic torticollis
Spasmodic torticollis is a chronic neurological movement disorder causing the neck to involuntarily turn to the left, right, upwards, and/or downwards. The condition is also referred to as "cervical dystonia". Both agonist and antagonist muscle contract simultaneously during dystonic...
and provides relief for approximately 12 to 16 weeks.
The anaerobic bacterium
Anaerobic organism
An anaerobic organism or anaerobe is any organism that does not require oxygen for growth. It could possibly react negatively and may even die if oxygen is present...
C. ljungdahlii
Clostridium ljungdahlii
Clostridium ljungdahlii is an anaerobic, motile, gram-positive bacterium. It can be used in the fermentation process for second generation biofuels....
, recently discovered in commercial chicken wastes, can produce ethanol from single-carbon sources including synthesis gas, a mixture of carbon monoxide
Carbon monoxide
Carbon monoxide , also called carbonous oxide, is a colorless, odorless, and tasteless gas that is slightly lighter than air. It is highly toxic to humans and animals in higher quantities, although it is also produced in normal animal metabolism in low quantities, and is thought to have some normal...
and hydrogen
Hydrogen
Hydrogen is the chemical element with atomic number 1. It is represented by the symbol H. With an average atomic weight of , hydrogen is the lightest and most abundant chemical element, constituting roughly 75% of the Universe's chemical elemental mass. Stars in the main sequence are mainly...
that can be generated from the partial combustion
Combustion
Combustion or burning is the sequence of exothermic chemical reactions between a fuel and an oxidant accompanied by the production of heat and conversion of chemical species. The release of heat can result in the production of light in the form of either glowing or a flame...
of either fossil fuel
Fossil fuel
Fossil fuels are fuels formed by natural processes such as anaerobic decomposition of buried dead organisms. The age of the organisms and their resulting fossil fuels is typically millions of years, and sometimes exceeds 650 million years...
s or biomass
Biomass
Biomass, as a renewable energy source, is biological material from living, or recently living organisms. As an energy source, biomass can either be used directly, or converted into other energy products such as biofuel....
. Use of these bacteria to produce ethanol from synthesis gas has progressed to the pilot plant stage at the BRI Energy facility in Fayetteville, Arkansas
Fayetteville, Arkansas
Fayetteville is the county seat of Washington County, and the third largest city in Arkansas. The city is centrally located within the county and is home to the University of Arkansas. Fayetteville is also deep in the Boston Mountains, a subset of The Ozarks...
.
Fatty acid
Fatty acid
In chemistry, especially biochemistry, a fatty acid is a carboxylic acid with a long unbranched aliphatic tail , which is either saturated or unsaturated. Most naturally occurring fatty acids have a chain of an even number of carbon atoms, from 4 to 28. Fatty acids are usually derived from...
s are converted by yeast
Yeast
Yeasts are eukaryotic micro-organisms classified in the kingdom Fungi, with 1,500 species currently described estimated to be only 1% of all fungal species. Most reproduce asexually by mitosis, and many do so by an asymmetric division process called budding...
s to long-chain dicarboxylic acid
Dicarboxylic acid
Dicarboxylic acids are organic compounds that contain two carboxylic acid functional groups. In molecular formulae for dicarboxylic acids, these groups are often written as HOOC-R-COOH, where R may be an alkyl, alkenyl, alkynyl, or aryl group...
s and then to 1,3-propanediol
1,3-Propanediol
1,3-Propanediol is the organic compound with the formula CH22. This three-carbon diol is a colorless viscous liquid that is miscible with water.-Products:...
using Clostridium diolis.
Genes from C. thermocellum
Clostridium thermocellum
Clostridium thermocellum is an anaerobic, thermophilic bacterium. C. thermocellum has garnered research interest due to its cellulolytic and ethanologenic abilities, being capable of directly converting a cellulosic substrate into ethanol. This makes it useful in converting biomass into a usable...
have been inserted into transgenic mice to allow the production of endoglucanase. The experiment was intended to learn more about how the digestive capacity of monogastric
Monogastric
A monogastric organism has a simple single-chambered stomach, whereas ruminants have a four-chambered complex stomach. Examples of monogastric animals include omnivores such as humans, rats and pigs, carnivores such as dogs and cats, and herbivores such as Horses and rabbits. Herbivores with...
animals could be improved. Hall et al. published their findings in 1993.
Non-pathogenic strains of Clostridium may help in the treatment of diseases such as cancer
Cancer
Cancer , known medically as a malignant neoplasm, is a large group of different diseases, all involving unregulated cell growth. In cancer, cells divide and grow uncontrollably, forming malignant tumors, and invade nearby parts of the body. The cancer may also spread to more distant parts of the...
. Research shows that Clostridium can selectively target cancer cells. Some strains can enter and replicate within solid tumours
Tumor
A tumor or tumour is commonly used as a synonym for a neoplasm that appears enlarged in size. Tumor is not synonymous with cancer...
. Clostridium could, therefore, be used to deliver therapeutic proteins to tumours. This use of Clostridium has been demonstrated in a variety of preclinical models.
External links
- Clostridium genomes and related information at PATRIC, a Bioinformatics Resource Center funded by NIAID
- Todar's Online Textbook of Bacteriology
- UK Clostridium difficile Support Group
- Pathema-Clostridium Resource
- Water analysis: Clostridium video