''Aspergillus wentii'' is an
asexual, filamentous,
endosymbiotic
An ''endosymbiont'' or ''endobiont'' is any organism that lives within the body or cells of another organism most often, though not always, in a mutualistic relationship.
(The term endosymbiosis is from the Greek: ἔνδον ''endon'' "within" ...
fungus
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 th ...
belonging to the
mold
A mold () or mould () is one of the structures certain fungus, fungi can form. The dust-like, colored appearance of molds is due to the formation of Spore#Fungi, spores containing Secondary metabolite#Fungal secondary metabolites, fungal seco ...
genus, ''
Aspergillus
' () is a genus consisting of several hundred mold species found in various climates worldwide.
''Aspergillus'' was first catalogued in 1729 by the Italian priest and biologist Pier Antonio Micheli. Viewing the fungi under a microscope, Miche ...
''.
[ It is a common soil fungus with a ]cosmopolitan distribution
In biogeography, cosmopolitan distribution is the term for the range of a taxon that extends across all or most of the world in appropriate habitats. Such a taxon, usually a species, is said to exhibit cosmopolitanism or cosmopolitism. The ext ...
, although it is primarily found in subtropical
The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical z ...
regions.[ Found on a variety of organic materials, ''A. wentii'' is known to colonize ]corn
Maize ( ; ''Zea mays'' subsp. ''mays'', from es, maíz after tnq, mahiz), also known as corn (North American and Australian English), is a cereal grain first domesticated by indigenous peoples in southern Mexico about 10,000 years ago. Th ...
, cereals
A cereal is any grass cultivated for the edible components of its grain (botanically, a type of fruit called a caryopsis), composed of the endosperm, germ, and bran. Cereal grain crops are grown in greater quantities and provide more food en ...
, moist grains
A grain is a small, hard, dry fruit (caryopsis) – with or without an attached hull layer – harvested for human or animal consumption. A grain crop is a grain-producing plant. The two main types of commercial grain crops are cereals and legume ...
, peanut
The peanut (''Arachis hypogaea''), also known as the groundnut, goober (US), pindar (US) or monkey nut (UK), is a legume crop grown mainly for its edible Seed, seeds. It is widely grown in the tropics and subtropics, important to both small ...
s and other ground nut crops.[ It is also used in the manufacture of ]biodiesel
Biodiesel is a form of diesel fuel derived from plants or animals and consisting of long-chain fatty acid esters. It is typically made by chemically reacting lipids such as animal fat (tallow), soybean oil, or some other vegetable oil with ...
from lipids and is known for its ability to produce enzymes used in the food industry.[
]
History and taxonomy
''Aspergillus wentii'' was first described by German mycologist Carl Friedrich Wilhelm Wehmer in 1896.[ Following a ]morphology
Morphology, from the Greek and meaning "study of shape", may refer to:
Disciplines
* Morphology (archaeology), study of the shapes or forms of artifacts
* Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies ...
-based classification scheme he created in 1901, Wehmer grouped ''A. wentii'' under a category of large ''Aspergilli'' that he called the "Macroaspergilli" due to its large fruiting body
The sporocarp (also known as fruiting body, fruit body or fruitbody) of fungi is a multicellular structure on which spore-producing structures, such as basidia or asci, are borne. The fruitbody is part of the sexual phase of a fungal life cyc ...
structure (the conidial head).[ The taxonomic position of ''A. wentii'' remained unclear within the genus as ''A. wentii'' Wehmer synonyms (''A. archaeoflavus'' Blochwitz][ and ''Aspergillus wentii'' var. ''minimus''][) were presented by Drs. Charles Thom and Kenneth Raper as possible variations or strains.][ The first ''A. wentii'' group was proposed by Drs. Thom and Raper in 1945.][ This original ''A. wentii'' group was classified under the Circumdati subgenus of the genus ''Aspergillus'' and included 4 fungal species currently known as '' A. avenaceus'' Smith, '' A. panamensis'' Raper and Thom, ''A. alliaceus'' Thom and Church, and ''A. wentii'' Wehmer.][ Presently, ''Aspergillus wentii'' Wehmer is the only remaining fungus of the four fungi that originally made up the "''A. wentii'' group".][ The 3 former members of the ''A. wentii'' group (''A. avenaceus'', ''A. panamensis'', and ''A. alliaceus'') have since been reassigned to different ''Aspergillus'' subgenera (''A. flavus'' group, ''A. ustus'' group, and ''A. ocheaceus'' group) respectively.][ Drs. Charles Thom and Dorothy Fennell revised the ''A. wentii'' group in 1965 to include ''Aspergillus thomii'' Smith and ''A. terricola'' Marchal along with ''A. wentii'' Wehmer.][ However, ''Aspergillus'' group classifications within subgenera became obsolete in the 1980s being replaced by sections.][
The new ''Aspergilli'' sections adapted and revised previously established morphological and ]physiological
Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical ...
characteristics of ''Aspergillli'' groups and incorporated DNA sequencing
DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, guanine, cytosine, and thymine. Th ...
analyses to confirm phylogenetic relationship
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups o ...
s among related ''Aspergilli''.[ Many species were reassigned to new ''Aspergilli'' sections as phylogenetic relationships were confirmed by DNA and ]genome sequencing
Whole genome sequencing (WGS), also known as full genome sequencing, complete genome sequencing, or entire genome sequencing, is the process of determining the entirety, or nearly the entirety, of the DNA sequence of an organism's genome at a ...
experiments.[ As a result, ''A. wentii'' and '' A. dimorphicus'', previously described as synonyms within the ''A. wentii'' section,][ were later confirmed to be distinct species.][
]
Growth and morphology
''Aspergillus wentii'' produces single-celled, globose, conidia
A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an asexual, non-motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also called mitospores due to the ...
(singular conidium) in unbranched, filamentous
The word filament, which is descended from Latin ''filum'' meaning " thread", is used in English for a variety of thread-like structures, including:
Astronomy
* Galaxy filament, the largest known cosmic structures in the universe
* Solar filament ...
chains.[ Young asexual conidia (also called spores) start off smooth, colourless, and ]ellipsoidal
An ellipsoid is a surface that may be obtained from a sphere by deforming it by means of directional scalings, or more generally, of an affine transformation.
An ellipsoid is a quadric surface; that is, a surface that may be defined as the z ...
before maturing into rough, globose spores approximately 4.5–5 µm in diameter.[ ''Aspergillus wentii'' conidia can appear anywhere from darker yellow to brown in colour when mature and have a single wall, unlike related species ''Aspergillus tamarii'' whose conidia have a double wall membrane.][ The elongating chains of conidia are dispersed through slightly pigmented, vase-shaped structures known as ]phialide
The phialide ( ; el, phialis, diminutive of phiale, a broad, flat vessel) is a flask-shaped projection from the vesicle (dilated part of the top of conidiophore) of certain fungi. It projects from the mycelium without increasing in length unless ...
s that are around 6–8 µm.[ The phialides sit on top of ]almond
The almond (''Prunus amygdalus'', syn. ''Prunus dulcis'') is a species of tree native to Iran and surrounding countries, including the Levant. The almond is also the name of the edible and widely cultivated seed of this tree. Within the genus ...
-shaped structures known as metulae that are about 10–20 µm in length and also slightly pigmented.[ Together, these metulae and phialides structures radiate outward from a ]spheroid
A spheroid, also known as an ellipsoid of revolution or rotational ellipsoid, is a quadric surface obtained by rotating an ellipse about one of its principal axes; in other words, an ellipsoid with two equal semi-diameters. A spheroid has cir ...
structure known as the vesicle
Vesicle may refer to:
; In cellular biology or chemistry
* Vesicle (biology and chemistry), a supramolecular assembly of lipid molecules, like a cell membrane
* Synaptic vesicle
; In human embryology
* Vesicle (embryology), bulge-like features o ...
, layering around its entire surface area.[ The vesicle can grow to a diameter of 80 µm, with a completely fertile spheroid surface area.][ Collectively, this large globose complex made up of the vesicle at the centre with metulae and phialides radiating outward is called the conidial head.][ The conidial head can vary from tan-yellow to darker coffee-coloured brown and grow as big as 500–800 µm in diameter.][ The conidial head is affixed atop of a thick, ]aseptate
In biology, a septum (Latin for ''something that encloses''; plural septa) is a wall, dividing a cavity or structure into smaller ones. A cavity or structure divided in this way may be referred to as septate.
Examples
Human anatomy
* Interatri ...
stalk known as a stipe. ''Aspergillus wentii'' stipes are notable for being interspersed and longer than average ''Aspergillus'' stalks.[ The stipe and conidial head together form a translucent, rod-shaped structure collectively known as the ]conidiophore
A conidium ( ; ), sometimes termed an asexual chlamydospore or chlamydoconidium (), is an Asexual reproduction, asexual, non-motility, motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are al ...
that in turn, extends from the hyphal tip.[ The conidiophore can grow anywhere between 3–5 millimeters in length, has a glassy appearance (described as ]hyaline
A hyaline substance is one with a glassy appearance. The word is derived from el, ὑάλινος, translit=hyálinos, lit=transparent, and el, ὕαλος, translit=hýalos, lit=crystal, glass, label=none.
Histopathology
Hyaline cartilage is ...
) and typically have a smooth texture, although granular
Granularity (also called graininess), the condition of existing in granules or grains, refers to the extent to which a material or system is composed of distinguishable pieces. It can either refer to the extent to which a larger entity is subd ...
conidiophores have been observed.[ ''Aspergillus wentii'' produces aerial ]hyphae
A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium.
Structure
A hypha consists of one or ...
, white or sometimes yellow in colour that can grow to a few millimeters in length.[ ''Aspergillus wentii'' foot cells have dense walls and are branched.][
Overall, ''Aspergillus wentii'' colonies appear dense, ]