![Agar plate with colonies](https://upload.wikimedia.org/wikipedia/commons/9/93/Agar_plate_with_colonies.jpg)
Microbiology () is the
scientific study
Scientific study is a kind of study that involves scientific theory, scientific models, experiments and physical situations. It may refer to:
*Scientific method, a body of techniques for investigating phenomena, based on empirical or measurabl ...
of
microorganism
A microorganism, or microbe,, ''mikros'', "small") and ''organism'' from the el, ὀργανισμός, ''organismós'', "organism"). It is usually written as a single word but is sometimes hyphenated (''micro-organism''), especially in olde ...
s, those being
unicellular
A unicellular organism, also known as a single-celled organism, is an organism that consists of a single cell, unlike a multicellular organism that consists of multiple cells. Organisms fall into two general categories: prokaryotic organisms and ...
(single cell),
multicellular
A multicellular organism is an organism that consists of more than one cell, in contrast to unicellular organism.
All species of animals, land plants and most fungi are multicellular, as are many algae, whereas a few organisms are partially uni- ...
(cell colony), or
acellular
Non-cellular life, or acellular life is life that exists without a cellular structure for at least part of its life cycle. Historically, most (descriptive) definitions of life postulated that an organism must be composed of one or more cells, ...
(lacking cells).
Microbiology encompasses numerous sub-disciplines including
virology
Virology is the Scientific method, scientific study of biological viruses. It is a subfield of microbiology that focuses on their detection, structure, classification and evolution, their methods of infection and exploitation of host (biology), ...
,
bacteriology,
protistology,
mycology
Mycology is the branch of biology concerned with the study of fungi, including their genetic and biochemical properties, their taxonomy and their use to humans, including as a source for tinder, traditional medicine, food, and entheogens, as ...
,
immunology
Immunology is a branch of medicineImmunology for Medical Students, Roderick Nairn, Matthew Helbert, Mosby, 2007 and biology that covers the medical study of immune systems in humans, animals, plants and sapient species. In such we can see there ...
, and
parasitology
Parasitology is the study of parasites, their hosts, and the relationship between them. As a biological discipline, the scope of parasitology is not determined by the organism or environment in question but by their way of life. This means it fo ...
.
Eukaryotic
Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacte ...
microorganisms possess membrane-bound
organelle
In cell biology, an organelle is a specialized subunit, usually within a cell, that has a specific function. The name ''organelle'' comes from the idea that these structures are parts of cells, as organs are to the body, hence ''organelle,'' the ...
s and include
fungi
A fungus ( : fungi or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and molds, as well as the more familiar mushrooms. These organisms are classified as a kingdom, separately from ...
and
protists
A protist () is any eukaryotic organism (that is, an organism whose cells contain a cell nucleus) that is not an animal, plant, or fungus. While it is likely that protists share a common ancestor (the last eukaryotic common ancestor), the excl ...
, whereas
prokaryotic organisms—all of which are microorganisms—are conventionally classified as lacking membrane-bound organelles and include
Bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
and
Archaea
Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebac ...
.
Microbiologist
A microbiologist (from Ancient Greek, Greek ) is a scientist who studies microscopic life forms and processes. This includes study of the growth, interactions and characteristics of Microorganism, microscopic organisms such as bacteria, algae, f ...
s traditionally relied on culture, staining, and
microscopy
Microscopy is the technical field of using microscopes to view objects and areas of objects that cannot be seen with the naked eye (objects that are not within the resolution range of the normal eye). There are three well-known branches of micr ...
. However, less than 1% of the microorganisms present in common environments can be cultured in isolation using current means.
Microbiologists often rely on
molecular biology
Molecular biology is the branch of biology that seeks to understand the molecular basis of biological activity in and between cells, including biomolecular synthesis, modification, mechanisms, and interactions. The study of chemical and physi ...
tools such as DNA sequence based identification, for example the
16S rRNA 16S rRNA may refer to:
* 16S ribosomal RNA
16 S ribosomal RNA (or 16 S rRNA) is the RNA component of the 30S subunit of a prokaryotic ribosome ( SSU rRNA). It binds to the Shine-Dalgarno sequence and provides most of the SSU structure.
The g ...
gene sequence used for bacteria identification.
Virus
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea.
Since Dmitri Ivanovsky's 1 ...
es have been variably classified as organisms, as they have been considered either as very simple microorganisms or very complex molecules.
Prions, never considered as microorganisms, have been investigated by virologists, however, as the clinical effects traced to them were originally presumed due to chronic viral infections, and virologists took search—discovering "infectious proteins".
The existence of microorganisms was predicted many centuries before they were first observed, for example by the
Jains
Jainism ( ), also known as Jain Dharma, is an Indian religion. Jainism traces its spiritual ideas and history through the succession of twenty-four tirthankaras (supreme preachers of ''Dharma''), with the first in the current time cycle being ...
in India and by
Marcus Terentius Varro in ancient Rome. The first recorded microscope observation was of the fruiting bodies of moulds, by
Robert Hooke
Robert Hooke FRS (; 18 July 16353 March 1703) was an English polymath active as a scientist, natural philosopher and architect, who is credited to be one of two scientists to discover microorganisms in 1665 using a compound microscope that ...
in 1666, but the Jesuit priest
Athanasius Kircher was likely the first to see microbes, which he mentioned observing in milk and putrid material in 1658.
Antonie van Leeuwenhoek
Antonie Philips van Leeuwenhoek ( ; ; 24 October 1632 – 26 August 1723) was a Dutch microbiologist and microscopist in the Golden Age of Dutch science and technology. A largely self-taught man in science, he is commonly known as " the ...
is considered a
father of microbiology as he observed and experimented with
microscopic organisms in the 1670s, using simple
microscope
A microscope () is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisibl ...
s of his own design. Scientific microbiology developed in the 19th century through the work of
Louis Pasteur
Louis Pasteur (, ; 27 December 1822 – 28 September 1895) was a French chemist and microbiologist renowned for his discoveries of the principles of vaccination, microbial fermentation and pasteurization, the latter of which was named afte ...
and in medical microbiology
Robert Koch
Heinrich Hermann Robert Koch ( , ; 11 December 1843 – 27 May 1910) was a German physician and microbiologist. As the discoverer of the specific causative agents of deadly infectious diseases including tuberculosis, cholera (though the Vibrio ...
.
History
![Avicenna TajikistanP17-20Somoni-1999 (cropped)](https://upload.wikimedia.org/wikipedia/commons/5/50/Avicenna_TajikistanP17-20Somoni-1999_%28cropped%29.png)
The existence of microorganisms was hypothesized for many centuries before their actual discovery. The existence of unseen microbiological life was postulated by
Jainism
Jainism ( ), also known as Jain Dharma, is an Indian religions, Indian religion. Jainism traces its spiritual ideas and history through the succession of twenty-four tirthankaras (supreme preachers of ''Dharma''), with the first in the current ...
which is based on
Mahavira
Mahavira (Sanskrit: महावीर) also known as Vardhaman, was the 24th ''tirthankara'' (supreme preacher) of Jainism. He was the spiritual successor of the 23rd ''tirthankara'' Parshvanatha. Mahavira was born in the early part of the 6t ...
's teachings as early as 6th century BCE (599 BC - 527 BC).
Paul Dundas notes that Mahavira asserted the existence of unseen microbiological creatures living in earth, water, air and fire.
Jain scriptures
Jain literature (Sanskrit: जैन साहित्य) refers to the literature of the Jain religion. It is a vast and ancient literary tradition, which was initially transmitted orally. The oldest surviving material is contained in the ca ...
describe
nigoda
In Jainism cosmology, the Nigoda is a realm existing in which the lowest forms of invisible life reside in endless numbers, and without any hope of release by self-effort. Jain scriptures describe nigodas which are microorganisms Kanti V. Mardia ...
s which are sub-microscopic creatures living in large clusters and having a very short life, said to pervade every part of the universe, even in tissues of plants and flesh of animals. The
Roman
Roman or Romans most often refers to:
*Rome, the capital city of Italy
*Ancient Rome, Roman civilization from 8th century BC to 5th century AD
*Roman people, the people of ancient Rome
*''Epistle to the Romans'', shortened to ''Romans'', a letter ...
Marcus Terentius Varro made references to microbes when he warned against locating a homestead in the vicinity of swamps "because there are bred certain minute creatures which cannot be seen by the eyes, which float in the air and enter the body through the mouth and nose and thereby cause serious diseases."
Persian scientists hypothesized the existence of microorganisms, such as
Avicenna
Ibn Sina ( fa, ابن سینا; 980 – June 1037 CE), commonly known in the West as Avicenna (), was a Persian polymath who is regarded as one of the most significant physicians, astronomers, philosophers, and writers of the Islamic G ...
in his book ''
The Canon of Medicine'',
Ibn Zuhr
Abū Marwān ‘Abd al-Malik ibn Zuhr ( ar, أبو مروان عبد الملك بن زهر), traditionally known by his Latinization of names, Latinized name Avenzoar (; 1094–1162), was an Arab Islamic medicine, physician, surgeon, and poet ...
(also known as Avenzoar) who discovered
scabies
Scabies (; also sometimes known as the seven-year itch) is a contagious skin infestation by the mite ''Sarcoptes scabiei''. The most common symptoms are severe itchiness and a pimple-like rash. Occasionally, tiny burrows may appear on the skin ...
mites, and
Al-Razi Razi ( fa, رازی) or al-Razi ( ar, الرازی) is a name that was historically used to indicate a person coming from Ray, Iran.
People
It most commonly refers to:
* Muhammad ibn Zakariya al-Razi (865–925), influential physician, alchemist ...
who gave the earliest known description of
smallpox
Smallpox was an infectious disease caused by variola virus (often called smallpox virus) which belongs to the genus Orthopoxvirus. The last naturally occurring case was diagnosed in October 1977, and the World Health Organization (WHO) c ...
in his book ''The Virtuous Life'' (al-Hawi).
In 1546,
Girolamo Fracastoro
Girolamo Fracastoro ( la, Hieronymus Fracastorius; c. 1476/86 August 1553) was an Italian physician, poet, and scholar in mathematics, geography and astronomy. Fracastoro subscribed to the philosophy of atomism, and rejected appeals to hidden c ...
proposed that
epidemic
An epidemic (from Ancient Greek, Greek ἐπί ''epi'' "upon or above" and δῆμος ''demos'' "people") is the rapid spread of disease to a large number of patients among a given population within an area in a short period of time.
Epidemics ...
diseases
A disease is a particular abnormal condition that negatively affects the structure or function of all or part of an organism, and that is not immediately due to any external injury. Diseases are often known to be medical conditions that ar ...
were caused by transferable seedlike entities that could transmit infection by direct or indirect contact, or vehicle transmission.
![Martinus Willem Beijerinck in his laboratory](https://upload.wikimedia.org/wikipedia/commons/0/0e/Martinus_Willem_Beijerinck_in_his_laboratory.jpg)
In 1676,
Antonie van Leeuwenhoek
Antonie Philips van Leeuwenhoek ( ; ; 24 October 1632 – 26 August 1723) was a Dutch microbiologist and microscopist in the Golden Age of Dutch science and technology. A largely self-taught man in science, he is commonly known as " the ...
, who lived most of his life in
Delft
Delft () is a List of cities in the Netherlands by province, city and Municipalities of the Netherlands, municipality in the Provinces of the Netherlands, province of South Holland, Netherlands. It is located between Rotterdam, to the southeast, ...
, Netherlands, observed
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
and other microorganisms using a
single-lens microscope of his own design.
He is considered a
father of microbiology as he used simple single-lensed
microscope
A microscope () is a laboratory instrument used to examine objects that are too small to be seen by the naked eye. Microscopy is the science of investigating small objects and structures using a microscope. Microscopic means being invisibl ...
s of his own design.
While Van Leeuwenhoek is often cited as the first to observe microbes,
Robert Hooke
Robert Hooke FRS (; 18 July 16353 March 1703) was an English polymath active as a scientist, natural philosopher and architect, who is credited to be one of two scientists to discover microorganisms in 1665 using a compound microscope that ...
made his first recorded microscopic observation, of the fruiting bodies of
moulds, in 1665. It has, however, been suggested that a Jesuit priest called
Athanasius Kircher was the first to observe microorganisms.
Kircher was among the first to design magic lanterns for projection purposes, so he must have been well acquainted with the properties of lenses.
[ He wrote "Concerning the wonderful structure of things in nature, investigated by Microscope" in 1646, stating "who would believe that vinegar and milk abound with an innumerable multitude of worms." He also noted that putrid material is full of innumerable creeping animalcules. He published his ''Scrutinium Pestis'' (Examination of the Plague) in 1658, stating correctly that the disease was caused by microbes, though what he saw was most likely red or white blood cells rather than the plague agent itself.][
]
The birth of bacteriology
The field of bacteriology (later a subdiscipline of microbiology) was founded in the 19th century by Ferdinand Cohn
Ferdinand Julius Cohn (24 January 1828 – 25 June 1898) was a German biologist. He is one of the founders of modern bacteriology and microbiology.
Ferdinand J. Cohn was born in the Jewish quarter of Breslau in the Kingdom of Prussia, Prussia ...
, a botanist whose studies on algae
Algae (; singular alga ) is an informal term for a large and diverse group of photosynthetic eukaryotic organisms. It is a polyphyletic grouping that includes species from multiple distinct clades. Included organisms range from unicellular mic ...
and photosynthetic bacteria
Photosynthesis is a process used by plants and other organisms to Energy transformation, convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemica ...
led him to describe several bacteria including '' Bacillus'' and ''Beggiatoa
''Beggiatoa'' is a genus of ''Gammaproteobacteria'' belonging the order ''Thiotrichales,'' in the ''Pseudomonadota'' phylum. This genus was one of the first bacteria discovered by Ukrainian botanist Sergei Sergei Winogradsky, Winogradsky. During ...
''. Cohn was also the first to formulate a scheme for the taxonomic classification of bacteria, and to discover endospore
An endospore is a dormant, tough, and non-reproductive structure produced by some bacteria in the phylum Bacillota. The name "endospore" is suggestive of a spore or seed-like form (''endo'' means 'within'), but it is not a true spore (i.e., no ...
s. Louis Pasteur
Louis Pasteur (, ; 27 December 1822 – 28 September 1895) was a French chemist and microbiologist renowned for his discoveries of the principles of vaccination, microbial fermentation and pasteurization, the latter of which was named afte ...
and Robert Koch
Heinrich Hermann Robert Koch ( , ; 11 December 1843 – 27 May 1910) was a German physician and microbiologist. As the discoverer of the specific causative agents of deadly infectious diseases including tuberculosis, cholera (though the Vibrio ...
were contemporaries of Cohn, and are often considered to be the fathers of modern microbiology[ and ]medical microbiology
Medical microbiology, the large subset of microbiology that is applied to medicine, is a branch of medical science concerned with the prevention, diagnosis and treatment of infectious diseases. In addition, this field of science studies various ...
, respectively. Pasteur is most famous for his series of experiments designed to disprove the then widely held theory of spontaneous generation
Spontaneous generation is a superseded scientific theory that held that living creatures could arise from nonliving matter and that such processes were commonplace and regular. It was hypothesized that certain forms, such as fleas, could arise fr ...
, thereby solidifying microbiology's identity as a biological science. One of his students, Adrien Certes, is considered the founder of marine microbiology. Pasteur also designed methods for food preservation
Food preservation includes processes that make food more resistant to microorganism growth and slow the oxidation of fats. This slows down the decomposition and rancidification process. Food preservation may also include processes that inhibit ...
(pasteurization
Pasteurization or pasteurisation is a process of food preservation in which packaged and non-packaged foods (such as milk and fruit juices) are treated with mild heat, usually to less than , to eliminate pathogens and extend shelf life.
The ...
) and vaccines against several diseases such as anthrax
Anthrax is an infection caused by the bacterium ''Bacillus anthracis''. It can occur in four forms: skin, lungs, intestinal, and injection. Symptom onset occurs between one day and more than two months after the infection is contracted. The sk ...
, fowl cholera and rabies
Rabies is a viral disease that causes encephalitis in humans and other mammals. Early symptoms can include fever and tingling at the site of exposure. These symptoms are followed by one or more of the following symptoms: nausea, vomiting, vi ...
. Koch is best known for his contributions to the germ theory of disease
The germ theory of disease is the currently accepted scientific theory for many diseases. It states that microorganisms known as pathogens or "germs" can lead to disease. These small organisms, too small to be seen without magnification, invade h ...
, proving that specific diseases were caused by specific pathogenic microorganisms. He developed a series of criteria that have become known as the Koch's postulates. Koch was one of the first scientists
A scientist is a person who conducts scientific research to advance knowledge in an area of the natural sciences.
In classical antiquity, there was no real ancient analog of a modern scientist. Instead, philosophers engaged in the philosophica ...
to focus on the isolation of bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...
in pure culture resulting in his description of several novel bacteria including ''Mycobacterium tuberculosis
''Mycobacterium tuberculosis'' (M. tb) is a species of pathogenic bacteria in the family Mycobacteriaceae and the causative agent of tuberculosis. First discovered in 1882 by Robert Koch, ''M. tuberculosis'' has an unusual, waxy coating on its c ...
'', the causative agent of tuberculosis
Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, in ...
.
While Pasteur and Koch are often considered the founders of microbiology, their work did not accurately reflect the true diversity of the microbial world because of their exclusive focus on microorganisms having direct medical relevance. It was not until the late 19th century and the work of Martinus Beijerinck and Sergei Winogradsky
Sergei Nikolaievich Winogradsky (or Vinohradsky; published under the name of Sergius Winogradsky or M. S. Winogradsky from Ukrainian Mykolayovych Serhiy; uk, Сергій Миколайович Виноградський; 1 September 1856 – ...
that the true breadth of microbiology was revealed. Beijerinck made two major contributions to microbiology: the discovery of virus
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea.
Since Dmitri Ivanovsky's 1 ...
es and the development of enrichment culture Enrichment culture is the use of certain growth media to favor the growth of a particular microorganism over others, enriching a sample for the microorganism of interest. This is generally done by introducing nutrients or environmental conditions th ...
techniques. While his work on the tobacco mosaic virus established the basic principles of virology, it was his development of enrichment culturing that had the most immediate impact on microbiology by allowing for the cultivation of a wide range of microbes with wildly different physiologies. Winogradsky was the first to develop the concept of chemolithotrophy
Lithotrophs are a diverse group of organisms using an inorganic substrate (usually of mineral origin) to obtain reducing equivalents for use in biosynthesis (e.g., carbon dioxide fixation) or energy conservation (i.e., ATP production) via aerobic ...
and to thereby reveal the essential role played by microorganisms in geochemical processes. He was responsible for the first isolation and description of both nitrifying and nitrogen-fixing bacteria
Nitrogen fixation is a chemical process by which molecular nitrogen (), with a strong triple covalent bond, in the air is converted into ammonia () or related nitrogenous compounds, typically in soil or aquatic systems but also in industry. Atmos ...
. French-Canadian microbiologist Felix d'Herelle
Felix may refer to:
* Felix (name), people and fictional characters with the name
Places
* Arabia Felix is the ancient Latin name of Yemen
* Felix, Spain, a municipality of the province Almería, in the autonomous community of Andalusia, S ...
co-discovered bacteriophage
A bacteriophage (), also known informally as a ''phage'' (), is a duplodnaviria virus that infects and replicates within bacteria and archaea. The term was derived from "bacteria" and the Greek φαγεῖν ('), meaning "to devour". Bacteri ...
s in 1917 and was one of the earliest applied microbiologists.
Joseph Lister
Joseph Lister, 1st Baron Lister, (5 April 182710 February 1912) was a British surgeon, medical scientist, experimental pathologist and a pioneer of antiseptic surgery and preventative medicine. Joseph Lister revolutionised the craft of s ...
was the first to use phenol
Phenol (also called carbolic acid) is an aromatic organic compound with the molecular formula . It is a white crystalline solid that is volatile. The molecule consists of a phenyl group () bonded to a hydroxy group (). Mildly acidic, it req ...
disinfectant on the open wounds of patients.
Branches
The branches of microbiology
The branches of microbiology can be classified into pure and applied sciences. Microbiology can be also classified based on taxonomy, in the cases of bacteriology, mycology, protozoology, and phycology. There is considerable overlap between the ...
can be classified into applied sciences, or divided according to taxonomy, as is the case with bacteriology, mycology
Mycology is the branch of biology concerned with the study of fungi, including their genetic and biochemical properties, their taxonomy and their use to humans, including as a source for tinder, traditional medicine, food, and entheogens, as ...
, protozoology Protozoology is the study of protozoa, the "animal-like" (i.e., motile and heterotrophic) protists. The Protozoa are considered to be a subkingdom of Protista. They are free-living organisms that are found in almost every habitat. All humans have pr ...
, virology
Virology is the Scientific method, scientific study of biological viruses. It is a subfield of microbiology that focuses on their detection, structure, classification and evolution, their methods of infection and exploitation of host (biology), ...
, phycology, and microbial ecology. There is considerable overlap between the specific branches of microbiology with each other and with other disciplines, and certain aspects of these branches can extend beyond the traditional scope of microbiology A pure research branch of microbiology is termed cellular microbiology
Cellular microbiology is a discipline that bridges microbiology and cell biology.
The term "cellular microbiology" was coined by the authors of the book of the same title published in 1996. Cooperation and mutual dependency between microbiology ...
.
Applications
While some people have fear of microbes due to the association of some microbes with various human diseases, many microbes are also responsible for numerous beneficial processes such as industrial fermentation (e.g. the production of alcohol
Alcohol most commonly refers to:
* Alcohol (chemistry), an organic compound in which a hydroxyl group is bound to a carbon atom
* Alcohol (drug), an intoxicant found in alcoholic drinks
Alcohol may also refer to:
Chemicals
* Ethanol, one of sev ...
, vinegar
Vinegar is an aqueous solution of acetic acid and trace compounds that may include flavorings. Vinegar typically contains 5–8% acetic acid by volume. Usually, the acetic acid is produced by a double fermentation, converting simple sugars to et ...
and dairy products), antibiotic
An antibiotic is a type of antimicrobial substance active against bacteria. It is the most important type of antibacterial agent for fighting bacterial infections, and antibiotic medications are widely used in the treatment and prevention of ...
production and act as molecular vehicles to transfer DNA to complex organisms such as plants and animals. Scientists have also exploited their knowledge of microbes to produce biotechnologically important enzyme
Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...
s such as Taq polymerase
''Taq'' polymerase is a thermostable DNA polymerase I named after the thermophilic eubacterial microorganism ''Thermus aquaticus,'' from which it was originally isolated by Chien et al. in 1976. Its name is often abbreviated to ''Taq'' or ''Ta ...
, reporter genes for use in other genetic systems and novel molecular biology techniques such as the yeast two-hybrid system
Two-hybrid screening (originally known as yeast two-hybrid system or Y2H) is a molecular biology technique used to discover protein–protein interactions (PPIs) and DNA-binding protein#Protein–DNA interactions, protein–DNA interactions by t ...
.
Bacteria can be used for the industrial production of amino acid
Amino acids are organic compounds that contain both amino and carboxylic acid functional groups. Although hundreds of amino acids exist in nature, by far the most important are the alpha-amino acids, which comprise proteins. Only 22 alpha am ...
s. ''Corynebacterium glutamicum'' is one of the most important bacterial species with an annual production of more than two million tons of amino acids, mainly L-glutamate and L-lysine. Since some bacteria have the ability to synthesize antibiotics, they are used for medicinal purposes, such as Streptomyces
''Streptomyces'' is the largest genus of Actinomycetota and the type genus of the family Streptomycetaceae. Over 500 species of ''Streptomyces'' bacteria have been described. As with the other Actinomycetota, streptomycetes are gram-positive, ...
to make aminoglycoside antibiotics.
A variety of biopolymer
Biopolymers are natural polymers produced by the cells of living organisms. Like other polymers, biopolymers consist of monomeric units that are covalently bonded in chains to form larger molecules. There are three main classes of biopolymers, cl ...
s, such as polysaccharide
Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with wa ...
s, polyester
Polyester is a category of polymers that contain the ester functional group in every repeat unit of their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). Polyesters include natural ...
s, and polyamide
A polyamide is a polymer with repeating units linked by amide bonds.
Polyamides occur both naturally and artificially. Examples of naturally occurring polyamides are proteins, such as wool and silk. Artificially made polyamides can be made through ...
s, are produced by microorganisms. Microorganisms are used for the biotechnological production of biopolymers with tailored properties suitable for high-value medical application such as tissue engineering
Tissue engineering is a biomedical engineering discipline that uses a combination of Cell (biology), cells, engineering, Materials science, materials methods, and suitable biochemistry, biochemical and physicochemical factors to restore, maintai ...
and drug delivery. Microorganisms are for example used for the biosynthesis of xanthan
Xanthan gum () is a polysaccharide with many industrial uses, including as a common food additive. It is an effective thickening agent, emulsifier, and stabilizer that prevents ingredients from separating. It can be produced from simple sugar ...
, alginate, cellulose
Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall ...
, cyanophycin, poly(gamma-glutamic acid), levan, hyaluronic acid
Hyaluronic acid (; abbreviated HA; conjugate base hyaluronate), also called hyaluronan, is an anionic, nonsulfated glycosaminoglycan distributed widely throughout connective, epithelial, and neural tissues. It is unique among glycosaminoglycans ...
, organic acids, oligosaccharide
An oligosaccharide (/ˌɑlɪgoʊˈsækəˌɹaɪd/; from the Greek ὀλίγος ''olígos'', "a few", and σάκχαρ ''sácchar'', "sugar") is a saccharide polymer containing a small number (typically two to ten) of monosaccharides (simple sugar ...
s polysaccharide
Polysaccharides (), or polycarbohydrates, are the most abundant carbohydrates found in food. They are long chain polymeric carbohydrates composed of monosaccharide units bound together by glycosidic linkages. This carbohydrate can react with wa ...
and polyhydroxyalkanoates.
Microorganisms are beneficial for microbial biodegradation Microbial biodegradation is the use of bioremediation and biotransformation methods to harness the naturally occurring ability of microbial xenobiotic metabolism to degrade, transform or accumulate environmental pollutants, including hydrocarbons (e ...
or bioremediation of domestic, agricultural and industrial wastes and subsurface pollution
Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...
in soils, sediments and marine environments. The ability of each microorganism to degrade toxic waste depends on the nature of each contaminant. Since sites typically have multiple pollutant types, the most effective approach to microbial biodegradation Microbial biodegradation is the use of bioremediation and biotransformation methods to harness the naturally occurring ability of microbial xenobiotic metabolism to degrade, transform or accumulate environmental pollutants, including hydrocarbons (e ...
is to use a mixture of bacterial and fungal species and strains, each specific to the biodegradation
Biodegradation is the breakdown of organic matter by microorganisms, such as bacteria and fungi. It is generally assumed to be a natural process, which differentiates it from composting. Composting is a human-driven process in which biodegrada ...
of one or more types of contaminants.
Symbiotic
Symbiosis (from Greek , , "living together", from , , "together", and , bíōsis, "living") is any type of a close and long-term biological interaction between two different biological organisms, be it mutualistic, commensalistic, or parasit ...
microbial communities confer benefits to their human and animal hosts health including aiding digestion, producing beneficial vitamins and amino acids, and suppressing pathogenic microbes. Some benefit may be conferred by eating fermented foods, probiotics (bacteria potentially beneficial to the digestive system) or prebiotics (substances consumed to promote the growth of probiotic microorganisms). The ways the microbiome influences human and animal health, as well as methods to influence the microbiome are active areas of research.
Research has suggested that microorganisms could be useful in the treatment of cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
. Various strains of non-pathogenic clostridia can infiltrate and replicate within solid tumors
A neoplasm () is a type of abnormal and excessive growth of tissue. The process that occurs to form or produce a neoplasm is called neoplasia. The growth of a neoplasm is uncoordinated with that of the normal surrounding tissue, and persists ...
. Clostridial vectors can be safely administered and their potential to deliver therapeutic proteins has been demonstrated in a variety of preclinical models.
Some bacteria are used to study fundamental mechanisms. An example of model bacteria used to study motility
Motility is the ability of an organism to move independently, using metabolic energy.
Definitions
Motility, the ability of an organism to move independently, using metabolic energy, can be contrasted with sessility, the state of organisms th ...
or the production of polysaccharides and development is '' Myxococcus xanthus''.
See also
*Biosafety
Biosafety is the prevention of large-scale loss of biological integrity, focusing both on ecology and human health.
These prevention mechanisms include conduction of regular reviews of the biosafety in laboratory settings, as well as strict guidel ...
*'' Microbes and Man''
;Professional organizations
* American Society for Microbiology
*Federation of European Microbiological Societies
Federation of European Microbiological Societies (FEMS) is an international European scientific organization, formed by the union of a number of national organizations; there are now 57 members from 41 European countries, regular and provisional. ...
*Society for Applied Microbiology
Applied Microbiology International, formally known as the Society for Applied Microbiology (SfAM), is the oldest microbiology society in the UK founded in 1931. Its object is to advance for the benefit of the public the science of microbiology in ...
*Society for General Microbiology
The Microbiology Society (previously the Society for General Microbiology) is a learned society based in the United Kingdom with a worldwide membership based in universities, industry, hospitals, research institutes and schools. It is the large ...
;Journals
*Critical Reviews in Microbiology
''Critical Reviews in Microbiology'' is an international, peer-reviewed academic journal that publishes comprehensive review articles covering all areas of medical microbiology. Areas covered by the journal include bacteriology, virology, microbial ...
*
* Journal of Bacteriology
*Nature Reviews Microbiology
''Nature Reviews Microbiology'' is a monthly peer-reviewed review journal published by Nature Portfolio. It was established in 2003. The journal publishes reviews and perspectives on microbiology, bridging fundamental research and its clinical, in ...
References
Further reading
*
*
External links
*
*
* nature.co
Latest Research, reviews and news on microbiology
Microbes.info
is a microbiology information portal containing a vast collection of resources including articles, news, frequently asked questions, and links pertaining to the field of microbiology.
*
* ttp://arjournals.annualreviews.org/loi/micro/ Annual Review of Microbiology
{{Authority control
Branches of biology
Microscopy