Home      Discussion      Topics      Dictionary      Almanac
Signup       Login
Bacillus subtilis

Bacillus subtilis

Overview
Bacillus subtilis, known also as the hay bacillus or grass bacillus, is a 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...

, catalase
Catalase
Catalase is a common enzyme found in nearly all living organisms that are exposed to oxygen, where it catalyzes the decomposition of hydrogen peroxide to water and oxygen...

-positive bacterium commonly found in soil. A member of the genus
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...

 Bacillus
Bacillus
Bacillus is a genus of Gram-positive, rod-shaped bacteria and a member of the division Firmicutes. Bacillus species can be obligate aerobes or facultative anaerobes, and test positive for the enzyme catalase. Ubiquitous in nature, Bacillus includes both free-living and pathogenic species...

, B. subtilis is rod-shaped, and has the ability to form a tough, protective 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...

, allowing the organism to tolerate extreme environmental conditions. Unlike several other well-known species, B. subtilis has historically been classified as an obligate aerobe
Aerobic organism
An aerobic organism or aerobe is an organism that can survive and grow in an oxygenated environment.Faculitative anaerobes grow and survive in an oxygenated environment and so do aerotolerant anaerobes.-Glucose:...

, though recent research has demonstrated that this is not strictly correct.

B.
Discussion
Ask a question about 'Bacillus subtilis'
Start a new discussion about 'Bacillus subtilis'
Answer questions from other users
Full Discussion Forum
 
Unanswered Questions
Encyclopedia
Bacillus subtilis, known also as the hay bacillus or grass bacillus, is a 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...

, catalase
Catalase
Catalase is a common enzyme found in nearly all living organisms that are exposed to oxygen, where it catalyzes the decomposition of hydrogen peroxide to water and oxygen...

-positive bacterium commonly found in soil. A member of the genus
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...

 Bacillus
Bacillus
Bacillus is a genus of Gram-positive, rod-shaped bacteria and a member of the division Firmicutes. Bacillus species can be obligate aerobes or facultative anaerobes, and test positive for the enzyme catalase. Ubiquitous in nature, Bacillus includes both free-living and pathogenic species...

, B. subtilis is rod-shaped, and has the ability to form a tough, protective 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...

, allowing the organism to tolerate extreme environmental conditions. Unlike several other well-known species, B. subtilis has historically been classified as an obligate aerobe
Aerobic organism
An aerobic organism or aerobe is an organism that can survive and grow in an oxygenated environment.Faculitative anaerobes grow and survive in an oxygenated environment and so do aerotolerant anaerobes.-Glucose:...

, though recent research has demonstrated that this is not strictly correct.

Pathogenesis


B. subtilis is only known to cause disease in severely immunocompromised patients, and can conversely be used as a probiotic
Probiotic
Probiotics are live microorganisms thought to be beneficial to the host organism. According to the currently adopted definition by FAO/WHO, probiotics are: "Live microorganisms which when administered in adequate amounts confer a health benefit on the host"...

 in healthy individuals. It may contaminate food but rarely causes food poisoning. B. subtilis produces the proteolytic enzyme subtilisin
Subtilisin
Subtilisin is a non-specific protease initially obtained from Bacillus subtilis.Subtilisins belong to subtilases, a group of serine proteases that initiate the nucleophilic attack on the peptide bond through a serine residue at the active site. They are physically and chemically...

. B. subtilis spores can survive the extreme heat during cooking. B. subtilis is responsible for causing ropiness — a sticky, stringy consistency caused by bacterial production of long-chain polysaccharide
Polysaccharide
Polysaccharides are long carbohydrate molecules, of repeated monomer units joined together by glycosidic bonds. They range in structure from linear to highly branched. Polysaccharides are often quite heterogeneous, containing slight modifications of the repeating unit. Depending on the structure,...

s — in spoiled bread dough.

Reproduction


B. subtilis can divide symmetrically to make two daughter cells (binary fission), or asymmetrically, producing a single 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...

 that can remain viable for decades and is resistant to unfavourable environmental conditions such as draught, salinity, extreme pH, radiation and solvents. The endospore is formed at times of nutritional stress, allowing the organism to persist in the environment until conditions become favorable. Prior to the process of sporulation the cells might become motile by producing lagella], take up DNA from the environment, or produce antibiotics. These responses are viewed as attempts to seek out nutrients by seeking a more favourable environment, enabling the cell to make use of new beneficial genetic material or simply by killing of competition.

Chromosomal replication


B. subtilis is a model organism
Model organism
A model organism is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the organism model will provide insight into the workings of other organisms. Model organisms are in vivo models and are widely used to...

 used to study bacterial chromosome replication. Replication of the single circular chromosome initiates at a single locus, the origin (oriC
Origin of replication
The origin of replication is a particular sequence in a genome at which replication is initiated. This can either be DNA replication in living organisms such as prokaryotes and eukaryotes, or RNA replication in RNA viruses, such as double-stranded RNA viruses...

). Replication proceeds bidirectionally and two replication fork
Replication fork
The replication fork is a structure that forms within the nucleus during DNA replication. It is created by helicases, which break the hydrogen bonds holding the two DNA strands together. The resulting structure has two branching "prongs", each one made up of a single strand of DNA...

s progress in clockwise and counterclockwise directions along the chromosome. Chromosome replication is completed when the forks reach the terminus region, which is positioned opposite to the origin on the chromosome map. The terminus region contains several short DNA sequences (Ter sites) that promote replication arrest. Specific proteins mediate all the steps in DNA replication. Comparison between the proteins involved in chromosomal DNA replication in B. subtilis and in Escherichia coli
Escherichia coli
Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...

reveals similarities and differences. Although the basic components promoting initiation, elongation, and termination of replication are well-conserved
Conserved sequence
In biology, conserved sequences are similar or identical sequences that occur within nucleic acid sequences , protein sequences, protein structures or polymeric carbohydrates across species or within different molecules produced by the same organism...

, some important differences can be found (such as one bacterium missing proteins essential in the other). These differences underline the diversity in the mechanisms and strategies that various bacterial species have adopted to carry out the duplication of their genomes.
Bacillisc

Model organism


B. subtilis has proven highly amenable to genetic manipulation, and has become widely adopted as a model organism
Model organism
A model organism is a non-human species that is extensively studied to understand particular biological phenomena, with the expectation that discoveries made in the organism model will provide insight into the workings of other organisms. Model organisms are in vivo models and are widely used to...

 for laboratory studies, especially of sporulation, which is a simplified example of cellular differentiation
Cellular differentiation
In developmental biology, cellular differentiation is the process by which a less specialized cell becomes a more specialized cell type. Differentiation occurs numerous times during the development of a multicellular organism as the organism changes from a simple zygote to a complex system of...

. It is also heavily flagellate
Flagellate
Flagellates are organisms with one or more whip-like organelles called flagella. Some cells in animals may be flagellate, for instance the spermatozoa of most phyla. Flowering plants do not produce flagellate cells, but ferns, mosses, green algae, some gymnosperms and other closely related plants...

d, which gives B. subtilis the ability to move quickly in liquids. In terms of popularity as a laboratory model organism, B. subtilis is often used as the Gram-positive equivalent of Escherichia coli
Escherichia coli
Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...

, an extensively studied Gram-negative
Gram-negative
Gram-negative bacteria are bacteria that do not retain crystal violet dye in the Gram staining protocol. In a Gram stain test, a counterstain is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color...

 bacterium.

Wild-type natural isolates of B. subtilis are difficult to work with compared to laboratory strains that have undergone domestication processes of mutagenesis and selection. These strains often have improved capabilities of transformation (uptake and integration of environmental DNA), growth, and loss of abilities needed "in the wild." And, while dozens of different strains fitting this description exist, the strain designated 168 is the most widely used.

Uses



B. subtilis is used as a soil inoculant
Soil inoculant
Soil inoculants are bacteria or fungi that are added to soils in order to improve plant growth by either:*Freeing up soil nutrients for plant use.*Entering into symbiotic relationships with plant root systems....

 in horticulture
Horticulture
Horticulture is the industry and science of plant cultivation including the process of preparing soil for the planting of seeds, tubers, or cuttings. Horticulturists work and conduct research in the disciplines of plant propagation and cultivation, crop production, plant breeding and genetic...

 and agriculture
Agriculture
Agriculture is the cultivation of animals, plants, fungi and other life forms for food, fiber, and other products used to sustain life. Agriculture was the key implement in the rise of sedentary human civilization, whereby farming of domesticated species created food surpluses that nurtured the...

. B. globigii, a closely related but phylogenetically distinct species was used as a biowarfare simulant during Project SHAD
Project SHAD
Project SHAD stands for Project Shipboard Hazard and Defense, a series of Cold War-era tests by the United States Department of Defense of biological weapons and chemical weapons...

 (aka Project 112).

Enzymes produced by B. subtilis and B. licheniformis
Bacillus licheniformis
Bacillus licheniformis is a bacterium commonly found in the soil. It is found on bird feathers, especially chest and back plumage, and most often in ground-dwelling birds and aquatic species ....

are widely used as additives in laundry detergent
Laundry detergent
Laundry detergent, or washing powder, is a substance that is a type of detergent that is added for cleaning laundry. In common usage, "detergent" refers to mixtures of chemical compounds including alkylbenzenesulfonates, which are similar to soap but are less affected by "hard water." In most...

s.

Its other uses include:
  • A strain of B. subtilis formerly known as Bacillus natto is used in the commercial production of the Japanese food natto
    Natto
    is a traditional Japanese food made from soybeans fermented with Bacillus subtilis. It is popular especially as a breakfast food. As a rich source of protein and probiotics, nattō and the soybean paste miso formed a vital source of nutrition in feudal Japan. Nattō can be an acquired taste because...

    , as well as the similar Korean food cheonggukjang
    Cheonggukjang
    Cheonggukjang is a fermented soybean paste used in Korean cuisine. It contains whole as well as ground soybeans.- Production :It can be made in 2 to 3 days through fermentation of boiled soybeans, adding Bacillus subtilis, which is usually contained in the air or in the jip, dried rice plants,...

    .
  • B. subtilis strain QST 713 (marketed as QST 713 or Serenade) has a natural fungicidal activity, and is employed as a biological control agent.
  • It was popular worldwide before the introduction of consumer antibiotics as an immunostimulatory agent to aid treatment of gastrointestinal and urinary tract diseases. It is still widely used in Western Europe and the Middle East as an alternative medicine
  • It can convert (decompose) some explosives into harmless compounds of nitrogen, carbon dioxide, and water.
  • Its surface binding properties play a role in safe radionuclide waste [e.g. thorium (IV) and plutonium (IV)] disposal.
  • Recombinant strains pBE2C1 and pBE2C1AB were used in production of polyhydroxyalkanoates
    Polyhydroxyalkanoates
    Polyhydroxyalkanoates or PHAs are linear polyesters produced in nature by bacterial fermentation of sugar or lipids. They are produced by the bacteria to store carbon and energy. More than 150 different monomers can be combined within this family to give materials with extremely different properties...

     (PHA), and malt waste can be used as their carbon source for lower cost PHA production.
  • It is used to produce amylase
    Amylase
    Amylase is an enzyme that catalyses the breakdown of starch into sugars. Amylase is present in human saliva, where it begins the chemical process of digestion. Food that contains much starch but little sugar, such as rice and potato, taste slightly sweet as they are chewed because amylase turns...

    .
  • It is used to produce hyaluronic acid, which is useful in the joint-care sector in healthcare.
  • It may provide some benefit to saffron
    Saffron
    Saffron is a spice derived from the flower of Crocus sativus, commonly known as the saffron crocus. Crocus is a genus in the family Iridaceae. Each saffron crocus grows to and bears up to four flowers, each with three vivid crimson stigmas, which are each the distal end of a carpel...

     growers by speeding corm growth and increasing stigma biomass yield.

Genome


B. subtilis has approximately 4,100 genes. Of these, only 192 were shown to be indispensable; another 79 were predicted to be essential as well. A vast majority of essential genes were categorized in relatively few domains of cell metabolism, with about half involved in information processing, one-fifth involved in the synthesis of cell envelope and the determination of cell shape and division, and one-tenth related to cell energetics.

Several non-coding RNA
Non-coding RNA
A non-coding RNA is a functional RNA molecule that is not translated into a protein. Less-frequently used synonyms are non-protein-coding RNA , non-messenger RNA and functional RNA . The term small RNA is often used for short bacterial ncRNAs...

s have been characterized in the B. subtilis genome, including Bsr RNAs
Bacillus subtilis BSR sRNAs
In a screen of the Bacillus subtilis genome for genes encoding ncRNAs, Saito et al. focused on 123 intergenic regions over 500 bp in length, the authors analyzed expression from these regions. Seven IGRs termed bsrC, bsrD, bsrE, bsrF, bsrG, bsrH and bsrI expressed RNAs smaller than 380 nt...

.

History


In 1835, the bacterium was originally named Vibrio subtilis by Christian Gottfried Ehrenberg
Christian Gottfried Ehrenberg
Christian Gottfried Ehrenberg , German naturalist, zoologist, comparative anatomist, geologist, and microscopist, was one of the most famous and productive scientists of his time.- Early collections :...

, and renamed Bacillus subtilis by Ferdinand Cohn
Ferdinand Cohn
Ferdinand Julius Cohn was a German biologist.Cohn was born in Breslau in the Prussian Province of Silesia. At the age of 10 he suffered hearing impairment. He received a degree in botany in 1847 at the age of nineteen at the University of Berlin. He was a teacher and researcher at University of...

 in 1872. Cultures of B. subtilis were used throughout the 1950s as an alternative medicine due to the immunostimulatory effects of its cell matter, which upon digestion has been found to significantly stimulate broad spectrum immune activity including activation of specific antibody IgM
IGM
IGM as an acronym or abbreviation can refer to:* Immunoglobulin M , the primary antibody against A and B antigens on red blood cells* International Grandmaster, a chess ranking* intergalactic medium* Intragroup medium - see: Intracluster medium...

, IgG and IgA
IGA
Iga or IGA may stand for:-Given name:* a female given name of Polish origin. The name originates from the female given name Jadwiga and stands for gia,or gina in the USA....

 secretion and release of CpG dinucleotides inducing INF A/Y producing activity of leukocytes and cytokines important in the development of cytotoxicity towards tumor cells. It was marketed throughout America and Europe from 1946 as an immunostimulatory aid in the treatment of gut and urinary tract diseases such as Rotavirus
Rotavirus
Rotavirus is the most common cause of severe diarrhoea among infants and young children, and is one of several viruses that cause infections often called stomach flu, despite having no relation to influenza. It is a genus of double-stranded RNA virus in the family Reoviridae. By the age of five,...

 and Shigella
Shigella
Shigella is a genus of Gram-negative, nonspore forming, non-motile, rod-shaped bacteria closely related to Escherichia coli and Salmonella. The causative agent of human shigellosis, Shigella causes disease in primates, but not in other mammals. It is only naturally found in humans and apes. During...

, but declined in popularity after the introduction of cheap consumer antibiotics, despite causing less chance of allergic reaction and significantly lower toxicity to normal gut flora.

External links

  • SubtiWiki: SubtiWiki "up-to-date information for all genes of Bacillus subtilis"
  • http://epa.gov/biotech_rule/pubs/fra/fra009.htm