Metarhizium anisopliae
Encyclopedia
Metarhizium anisopliae, formerly known as Entomophthora anisopliae (basionym
), is a fungus
that grows naturally in soils throughout the world and causes disease in various insect
s by acting as a parasite. Ilya I. Mechnikov
named it after the insect species it was originally isolated from: the beetle
Anisoplia austriaca
. It is a mitosporic fungus with asexual reproduction
, which was formerly classified in the form class
Hyphomycetes
of the form phylum
Deuteromycota (also often called Fungi Imperfecti
).
It has long been recognised that many isolates are specific, and they were assigned variety
status, but they have now been assigned as new Metarhizium
species, such as M. anisopliae, M. majus
and M. acridum
(which was M. anisopliae var. acridum and included the isolates used for locust control
). Metarhizium taii was placed in M. anisopliae var. anisopliae, but has now been described as a synonym of M. guizhouense (see Metarhizium
).
s. When these mitotic (asexual) spores (called conidia
) of the fungus come into contact with the body of an insect host, they germinate and the hypha
e that emerge penetrate the cuticle
. The fungus then develops inside the body eventually killing the insect after a few days; this lethal effect is very likely aided by the production of insecticidal cyclic peptide
s (destruxins). The cuticle of the cadaver often becomes red. If the ambient humidity is high enough, a white mould then grows on the cadaver that soon turns green as spores are produced. Most insects living near the soil have evolved natural defenses against entomopathogenic fungi like M. anisopliae. This fungus is therefore locked in an evolutionary battle to overcome these defenses, which has led to a large number of isolates
(or strains
) that are adapted to certain groups of insects.
is known to infect over 200 insect pest species, including termites. It is currently being used as a biological insecticide
to control a number of pests such as termite
s, thrips
, etc. and its use in the control of malaria
-transmitting mosquito
es is under investigation. M. anisopliae does not appear to infect humans or other animals and is considered safe as an insecticide. The microscopic spores are typically sprayed on affected areas. A possible technique for malaria
control is to coat mosquito net
s or cotton sheets attached to the wall with them.
In August 2007, a team of scientists at the Indian Institute of Chemical Technology discovered a more efficient way of producing biodiesel
which uses lipase
, an enzyme
produced in significant quantities by Metarhizium anisopliae; as opposed to other reactions which use enzymes that require heat in order to become active, the reaction that uses lipase runs at room temperature. The fungus is now a candidate for mass production of the enzyme.
Basionym
Basionym is a term used in botany, regulated by the International Code of Botanical Nomenclature...
), is a fungus
Fungus
A fungus is a member of a large 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, Fungi, which is separate from plants, animals, and bacteria...
that grows naturally in soils throughout the world and causes disease in various insect
Insect
Insects are a class of living creatures within the arthropods that have a chitinous exoskeleton, a three-part body , three pairs of jointed legs, compound eyes, and two antennae...
s by acting as a parasite. Ilya I. Mechnikov
Ilya Ilyich Mechnikov
Ilya Ilyich Mechnikov was a Russian biologist, zoologist and protozoologist, best remembered for his pioneering research into the immune system. Mechnikov received the Nobel Prize in Medicine in 1908, shared with Paul Ehrlich, for his work on phagocytosis...
named it after the insect species it was originally isolated from: the beetle
Beetle
Coleoptera is an order of insects commonly called beetles. The word "coleoptera" is from the Greek , koleos, "sheath"; and , pteron, "wing", thus "sheathed wing". Coleoptera contains more species than any other order, constituting almost 25% of all known life-forms...
Anisoplia austriaca
Anisoplia austriaca
Anisoplia austriaca is the binomial name of a species of scarab beetle, a harmful pest of cereal crops. Its body length is 12–16 mm.- Area of distribution :Anisoplia is distributed in the steppe zones of Europe, Asia Minor, Iran...
. It is a mitosporic fungus with asexual reproduction
Asexual reproduction
Asexual reproduction is a mode of reproduction by which offspring arise from a single parent, and inherit the genes of that parent only, it is reproduction which does not involve meiosis, ploidy reduction, or fertilization. A more stringent definition is agamogenesis which is reproduction without...
, which was formerly classified in the form class
Class (biology)
In biological classification, class is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, order, family, genus, and species, with class fitting between phylum and order...
Hyphomycetes
Hyphomycetes
Hyphomycetes is an obsolete class of fungi in the equally obsolete phylum Deuteromycota that lack fruiting bodies. Most hyphomycetes have now been assigned to the Ascomycota, mainly as a result of DNA sequencing, but many remain unassigned...
of the form phylum
Phylum
In biology, a phylum The term was coined by Georges Cuvier from Greek φῦλον phylon, "race, stock," related to φυλή phyle, "tribe, clan." is a taxonomic rank below kingdom and above class. "Phylum" is equivalent to the botanical term division....
Deuteromycota (also often called Fungi Imperfecti
Fungi imperfecti
The Fungi imperfecti or imperfect fungi, also known as Deuteromycota, are fungi which do not fit into the commonly established taxonomic classifications of fungi that are based on biological species concepts or morphological characteristics of sexual structures because their sexual form of...
).
It has long been recognised that many isolates are specific, and they were assigned variety
Variety (biology)
In botanical nomenclature, variety is a taxonomic rank below that of species: as such, it gets a three-part infraspecific name....
status, but they have now been assigned as new Metarhizium
Metarhizium
Metarhizium is a genus of entomopathogenic fungi in the Clavicipitaceae family. With the advent of genetic profiling, it has now become possible to place these fungi in proper taxa. Most turn out to be the asexual forms of fungi in the phylum Ascomycota.- Species :Nine distinct species have now...
species, such as M. anisopliae, M. majus
Metarhizium majus
Metarhizium majus is the new name given to a group of fungal isolates that are known to be virulent against Scarabaeidae, a family of beetles. Previously, this species has had variety status in Metarhizium anisopliae and its name is derived from characteristically very large spores for the genus...
and M. acridum
Metarhizium acridum
Metarhizium acridum is the new name given to a group of fungal isolates that are known to be virulent and specific to Acrididea. Previously, this species has had variety status in Metarhizium anisopliae and before that, reference was made to M. flavoviride.- Biology :M...
(which was M. anisopliae var. acridum and included the isolates used for locust control
Locust
Locusts are the swarming phase of short-horned grasshoppers of the family Acrididae. These are species that can breed rapidly under suitable conditions and subsequently become gregarious and migratory...
). Metarhizium taii was placed in M. anisopliae var. anisopliae, but has now been described as a synonym of M. guizhouense (see Metarhizium
Metarhizium
Metarhizium is a genus of entomopathogenic fungi in the Clavicipitaceae family. With the advent of genetic profiling, it has now become possible to place these fungi in proper taxa. Most turn out to be the asexual forms of fungi in the phylum Ascomycota.- Species :Nine distinct species have now...
).
Biology
The disease caused by the fungus is sometimes called green muscardine disease because of the green colour of its sporeSpore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...
s. When these mitotic (asexual) spores (called conidia
Conidium
Conidia, sometimes termed conidiospores, are asexual, non-motile spores of a fungus and are named after the greek word for dust, konia. They are also called mitospores due to the way they are generated through the cellular process of mitosis...
) of the fungus come into contact with the body of an insect host, they germinate and the hypha
Hypha
A hypha is a long, branching filamentous structure of a fungus, and also of unrelated Actinobacteria. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium; yeasts are unicellular fungi that do not grow as hyphae.-Structure:A hypha consists of one or...
e that emerge penetrate the cuticle
Cuticle
A cuticle , or cuticula, is a term used for any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticles" are non-homologous; differing in their origin, structure, function, and chemical composition...
. The fungus then develops inside the body eventually killing the insect after a few days; this lethal effect is very likely aided by the production of insecticidal cyclic peptide
Peptide
Peptides are short polymers of amino acid monomers linked by peptide bonds. They are distinguished from proteins on the basis of size, typically containing less than 50 monomer units. The shortest peptides are dipeptides, consisting of two amino acids joined by a single peptide bond...
s (destruxins). The cuticle of the cadaver often becomes red. If the ambient humidity is high enough, a white mould then grows on the cadaver that soon turns green as spores are produced. Most insects living near the soil have evolved natural defenses against entomopathogenic fungi like M. anisopliae. This fungus is therefore locked in an evolutionary battle to overcome these defenses, which has led to a large number of isolates
Primary isolate
Primary isolate is a pure microbial or viral sample that has been obtained from an infected individual, rather than grown in a laboratory. In chemistry and bacteriology, the verb isolate means to obtain a pure chemical, bacteriological or viral sample...
(or strains
Strain (biology)
In biology, a strain is a low-level taxonomic rank used in three related ways.-Microbiology and virology:A strain is a genetic variant or subtype of a micro-organism . For example, a "flu strain" is a certain biological form of the influenza or "flu" virus...
) that are adapted to certain groups of insects.
Economic Importance
This entomopathogenic fungusEntomopathogenic fungus
An entomopathogenic fungus is a fungus that can act as a parasite of insects and kills or seriously disables them.-Typical life cycle:These fungi usually attach to the external body surface of insects in the form of microscopic spores...
is known to infect over 200 insect pest species, including termites. It is currently being used as a biological insecticide
Insecticide
An insecticide is a pesticide used against insects. They include ovicides and larvicides used against the eggs and larvae of insects respectively. Insecticides are used in agriculture, medicine, industry and the household. The use of insecticides is believed to be one of the major factors behind...
to control a number of pests such as termite
Termite
Termites are a group of eusocial insects that, until recently, were classified at the taxonomic rank of order Isoptera , but are now accepted as the epifamily Termitoidae, of the cockroach order Blattodea...
s, thrips
Thrips
Thrips are tiny, slender insects with fringed wings . Other common names for thrips include thunderflies, thunderbugs, storm flies, thunderblights, and corn lice...
, etc. and its use in the control of malaria
Malaria
Malaria is a mosquito-borne infectious disease of humans and other animals caused by eukaryotic protists of the genus Plasmodium. The disease results from the multiplication of Plasmodium parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases...
-transmitting mosquito
Mosquito
Mosquitoes are members of a family of nematocerid flies: the Culicidae . The word Mosquito is from the Spanish and Portuguese for little fly...
es is under investigation. M. anisopliae does not appear to infect humans or other animals and is considered safe as an insecticide. The microscopic spores are typically sprayed on affected areas. A possible technique for malaria
Malaria
Malaria is a mosquito-borne infectious disease of humans and other animals caused by eukaryotic protists of the genus Plasmodium. The disease results from the multiplication of Plasmodium parasites within red blood cells, causing symptoms that typically include fever and headache, in severe cases...
control is to coat mosquito net
Mosquito net
A mosquito net offers protection against mosquitos, flies, and other insects, and thus against diseases such as malaria, dengue fever, yellow fever, and various forms of encephalitis, including the West Nile virus, if used properly and especially if treated with an insecticide, which can double...
s or cotton sheets attached to the wall with them.
In August 2007, a team of scientists at the Indian Institute of Chemical Technology discovered a more efficient way of producing biodiesel
Biodiesel
Biodiesel refers to a vegetable oil- or animal fat-based diesel fuel consisting of long-chain alkyl esters. Biodiesel is typically made by chemically reacting lipids with an alcohol....
which uses lipase
Lipase
A lipase is an enzyme that catalyzes the formation or cleavage of fats . Lipases are a subclass of the esterases.Lipases perform essential roles in the digestion, transport and processing of dietary lipids in most, if not all, living organisms...
, an enzyme
Enzyme
Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...
produced in significant quantities by Metarhizium anisopliae; as opposed to other reactions which use enzymes that require heat in order to become active, the reaction that uses lipase runs at room temperature. The fungus is now a candidate for mass production of the enzyme.
Important Isolates
- The the ex-neotype isolate of M. anisopliae is IMI 168777ii = ARSEF 7487 (also CSIRO FI-1029) from Schistocerca gregaria in EritreaEritreaEritrea , officially the State of Eritrea, is a country in the Horn of Africa. Eritrea derives it's name from the Greek word Erethria, meaning 'red land'. The capital is Asmara. It is bordered by Sudan in the west, Ethiopia in the south, and Djibouti in the southeast...
- M. anisopliae isolateIsolateIsolate may refer to:* Genetic isolate, a population of organisms that has little genetic mixing with other organisms of the same species* Isolate , 2007* Isolate , 1992...
F52 (029056) primarily infects beetle larvae: it is the active ingredient of 'BIO 1020', originally developed for control of Otiorhynchus sulcatus and now 'Met52' - A.C. Rath's isolate F506 (= ARSEF 4556; DAT 506; IMI 384583) from Boophilus sp. (Acari: Ixodidae) in USA (Florida)
- M. anisopliae isolated from Dermolepida albohirtum (Coleoptera: ScarabaeidaeScarabaeidaeThe family Scarabaeidae as currently defined consists of over 30,000 species of beetles worldwide. The species in this large family are often called scarabs or scarab beetles. The classification of this family is fairly unstable, with numerous competing theories, and new proposals appearing quite...
) include: CSIRO FI-1358 (= ARSEF 7493) and FI 1045 which is the active ingredient of 'Biocane'.
See also
- Beauveria bassianaBeauveria bassianaBeauveria bassiana is a fungus that grows naturally in soils throughout the world and acts as a parasite on various arthropod species, causing white muscardine disease; it thus belongs to the entomopathogenic fungi. It is being used as a biological insecticide to control a number of pests such as...
, the fungus that causes white muscardine disease in various insects - Biological insecticides
- LUBILOSALUBILOSALUBILOSA was the name of a research programme that aimed at developing a biological alternative to the chemical control of locusts. This name is an acronym of the French title of the programme: Lutte Biologique contre les Locustes et les Sauteriaux...
External links
- Index Fungorum record, links to a list of synonyms
- http://blog.wired.com/wiredscience/2007/08/fungi-make-biod.html Fungi Make Biodiesel Efficiently at Room Temperature