genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
of
mold
A mold () or mould () is one of the structures that 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 ...
s,
hyphomycetes
Hyphomycetes are a form classification of fungi, part of what has often been referred to as fungi imperfecti, Deuteromycota, or anamorphic fungi. Hyphomycetes lack closed fruit bodies, and are often referred to as moulds (or molds). Most hypho ...
fungi
A fungus (: fungi , , , or ; or funguses) is any member of the group of eukaryotic organisms that includes microorganisms such as yeasts and mold (fungus), molds, as well as the more familiar mushrooms. These organisms are classified as one ...
, now placed in the family
Stachybotryaceae
The Stachybotryaceae are a family of fungi in the order Hypocreales; the genera it contains have been described as "hyper-diverse".
The family was originally introduced by Crous et al. (2014) to accommodate three genera; ''Myrothecium'', ''Peet ...
. The genus was erected by
August Carl Joseph Corda
August Carl Joseph Corda (15 November 1809 – 1849) was a physician, botanist, and mycologist from Bohemia. This botanist is denoted by the List of botanists by author abbreviation, author abbreviation Corda when Author citation (botany), citing ...
in 1837. Historically, it was considered closely related to the genus ''Memnoniella'', because the
spore
In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores fo ...
s are produced in slimy heads rather than in dry chains. Recently, the synonymy of the two genera is generally accepted. Most ''Stachybotrys'' species inhabit materials rich in
cellulose
Cellulose is an organic compound with the chemical formula, formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of glycosidic bond, β(1→4) linked glucose, D-glucose units. Cellulose is an important s ...
. The genus has a widespread distribution and contained about 50 species in 2008. There are 88 records of ''Stachybotrys'' on
Species Fungorum
''Index Fungorum'' is an international project to index all formal names (Binomial nomenclature, scientific names) in the fungus Kingdom (biology), kingdom. As of 2015, the project is based at the Royal Botanic Gardens, Kew, one of three partn ...
(in 2023), of which 33 species have DNA sequence data in
GenBank
The GenBank sequence database is an open access, annotated collection of all publicly available nucleotide sequences and their protein translations. It is produced and maintained by the National Center for Biotechnology Information (NCBI; a par ...
. Species in the genus are commonly found in soil, plant litter (hay, straw, cereal grains, and decaying plant debris) and air and a few species have been found from damp paper, cotton, linen, cellulose-based building materials water-damaged indoor buildings, and air ducts from both aquatic and terrestrial habitats (Izabel et al. 2010; Lombard et al. 2016; Hyde et al. 2020a).
The name of ''Stachybotrys'' is derived from the
Greek
Greek may refer to:
Anything of, from, or related to Greece, a country in Southern Europe:
*Greeks, an ethnic group
*Greek language, a branch of the Indo-European language family
**Proto-Greek language, the assumed last common ancestor of all kno ...
words σταχυς ''stakhus'' (ear of grain, stalk, stick; metaphorically, progeny) and βότρυς ''botrus'' (cluster or bunch as in grapes, trusses).
The most infamous species, '' Stachybotrys chartarum'' (previously known as ''Stachybotrys atra'') and ''Stachybotrys chlorohalonata'', are known as black mold or toxic black mold in the U.S., and are frequently associated with poor
indoor air quality
Indoor air quality (IAQ) is the air quality within buildings and Nonbuilding structure, structures. Poor indoor air quality due to indoor air pollution is known to affect the health, comfort, and well-being of building occupants. It has also be ...
that arises after fungal growth on water-damaged building materials. ''Stachybotrys''
chemotypes A chemotype (sometimes chemovar) is a chemically distinct entity in a plant or microorganism, with differences in the composition of the secondary metabolites. Minor genetic and epigenetic changes with little or no effect on morphology or anatomy m ...
are toxic, with one producing
trichothecene
Trichothecenes constitute a large group of chemically related mycotoxins. They are produced by Fungus, fungi of the genera ''Fusarium'', ''Myrothecium'', ''Trichoderma'', ''Podostroma'', ''Trichothecium'', ''Cephalosporium'', ', ''Stachybotrys'' ...
mycotoxins
A mycotoxin (from the Greek μύκης , "fungus" and τοξικός , "poisonous") is a toxic secondary metabolite produced by fungi and is capable of causing disease and death in both humans and other animals. The term 'mycotoxin' is usually r ...
including
satratoxin
Satratoxin-H, a trichothecene mycotoxin, is a naturally occurring toxin produced by the ascomycetes '' Stachybotrys chartarum'' and '' Trichoderma cornu-damae'' which is highly toxic and potentially fatal to humans and other animals. The clinica ...
s, and another that produces atranones. However, the association of ''Stachybotrys'' mold with specific health conditions is not well proven and there exists a debate within the scientific community.
Conidia
Conidia
A conidium ( ; : conidia), sometimes termed an asexual chlamydospore or chlamydoconidium (: chlamydoconidia), is an asexual, non- motile spore of a fungus. The word ''conidium'' comes from the Ancient Greek word for dust, ('). They are also ...
are in slimy masses, smooth to coarsely rough, dark olivaceous to brownish black, obovoid, later becoming ellipsoid with age, 10–13 × 5–7 mm.
Phialide
The phialide ( ; , 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 a subsequ ...
s are obovate or ellipsoidal, colorless early then turning to olivaceous with maturity, smooth, 12–14 × 5–7 mm, in clusters of 5 to 9 phialides. Conidiophores are simple, erect, smooth to rough, colorless to olivaceous, slightly enlarged apically, mostly unbranched but occasionally branched. Conidia of ''Stachybotrys'' are very characteristic and can be confidently identified in spore count samples. This genus is closely related to ''Memnoniella''. Species of ''Memnoniella'' may occasionally develop ''Stachybotrys''-like conidia, and vice versa.
Detection
Four distinctive microbial
volatile organic compound
Volatile organic compounds (VOCs) are organic compounds that have a high vapor pressure at room temperature. They are common and exist in a variety of settings and products, not limited to Indoor mold, house mold, Upholstery, upholstered furnitur ...
s (MVOCs) –
1-butanol
1-Butanol, also known as butan-1-ol or ''n''-butanol, is a primary alcohol with the chemical formula C4H9OH and a linear structure. Isomers of 1-butanol are isobutanol, butan-2-ol and ''tert''-butanol. The unmodified term butanol usually refers ...
gypsum board
Drywall (also called plasterboard, dry lining, wallboard, sheet rock, gib board, gypsum board, buster board, turtles board, slap board, custard board, gypsum panel and gyprock) is a panel made of calcium sulfate dihydrate (gypsum), with or witho ...
cultures.
Pathogenicity
Symptoms of ''Stachybotrys'' exposure in humans
A controversy began in the early 1990s after analysis of two infant deaths and multiple cases in children from the poor areas of
Cleveland
Cleveland is a city in the U.S. state of Ohio and the county seat of Cuyahoga County. Located along the southern shore of Lake Erie, it is situated across the Canada–U.S. maritime border and approximately west of the Ohio-Pennsylvania st ...
, Ohio, United States, due to
pulmonary hemorrhage
Pulmonary hemorrhage (or pulmonary haemorrhage) is an acute bleeding from the lung, from the upper respiratory tract and the trachea, and the pulmonary alveoli. When evident clinically, the condition is usually massive.Stachybotrys chartarum''. Subsequent and extensive reanalysis of the cases by the United States
Centers for Disease Control and Prevention
The Centers for Disease Control and Prevention (CDC) is the National public health institutes, national public health agency of the United States. It is a Federal agencies of the United States, United States federal agency under the United S ...
have failed to find any link between the deaths and the mold exposure.
Species
As accepted by
Species Fungorum
''Index Fungorum'' is an international project to index all formal names (Binomial nomenclature, scientific names) in the fungus Kingdom (biology), kingdom. As of 2015, the project is based at the Royal Botanic Gardens, Kew, one of three partn ...
Stachybotrys biformis
''Stachybotrys'' () is a genus of molds, hyphomycetes or asexually reproducing, filamentous fungi, now placed in the family Stachybotryaceae. The genus was erected by August Carl Joseph Corda in 1837. Historically, it was considered closely re ...
Stachybotrys clitoriae
''Stachybotrys'' () is a genus of molds, hyphomycetes or asexually reproducing, filamentous fungi, now placed in the family Stachybotryaceae. The genus was erected by August Carl Joseph Corda in 1837. Historically, it was considered closely re ...
''
* ''
Stachybotrys cordylines
''Stachybotrys'' () is a genus of molds, hyphomycetes or asexually reproducing, filamentous fungi, now placed in the family Stachybotryaceae. The genus was erected by August Carl Joseph Corda in 1837. Historically, it was considered closely re ...
Stachybotrys gamsii
''Stachybotrys'' () is a genus of molds, hyphomycetes or asexually reproducing, filamentous fungi, now placed in the family Stachybotryaceae. The genus was erected by August Carl Joseph Corda in 1837. Historically, it was considered closely re ...
Stachybotrys havanensis
''Stachybotrys'' () is a genus of molds, hyphomycetes or asexually reproducing, filamentous fungi, now placed in the family Stachybotryaceae. The genus was erected by August Carl Joseph Corda in 1837. Historically, it was considered closely re ...
Stachybotrys indicoides
''Stachybotrys'' () is a genus of molds, hyphomycetes or asexually reproducing, filamentous fungi, now placed in the family Stachybotryaceae. The genus was erected by August Carl Joseph Corda in 1837. Historically, it was considered closely re ...
Stachybotrys mohanramii
''Stachybotrys'' () is a genus of molds, hyphomycetes or asexually reproducing, filamentous fungi, now placed in the family Stachybotryaceae. The genus was erected by August Carl Joseph Corda in 1837. Historically, it was considered closely re ...
Stachybotrys pallidus
''Stachybotrys'' () is a genus of molds, hyphomycetes or asexually reproducing, filamentous fungi, now placed in the family Stachybotryaceae. The genus was erected by August Carl Joseph Corda in 1837. Historically, it was considered closely re ...
Stachybotrys parvus
''Stachybotrys'' () is a genus of molds, hyphomycetes or asexually reproducing, filamentous fungi, now placed in the family Stachybotryaceae. The genus was erected by August Carl Joseph Corda in 1837. Historically, it was considered closely re ...
Stachybotrys reniformis
''Stachybotrys'' () is a genus of molds, hyphomycetes or asexually reproducing, filamentous fungi, now placed in the family Stachybotryaceae. The genus was erected by August Carl Joseph Corda in 1837. Historically, it was considered closely re ...
Stachybotrys subreniformis
''Stachybotrys'' () is a genus of molds, hyphomycetes or asexually reproducing, filamentous fungi, now placed in the family Stachybotryaceae. The genus was erected by August Carl Joseph Corda in 1837. Historically, it was considered closely re ...
''
* ''
Stachybotrys subsylvaticus
''Stachybotrys'' () is a genus of molds, hyphomycetes or asexually reproducing, filamentous fungi, now placed in the family Stachybotryaceae. The genus was erected by August Carl Joseph Corda in 1837. Historically, it was considered closely re ...
Stachybotrys variabilis
''Stachybotrys'' () is a genus of molds, hyphomycetes or asexually reproducing, filamentous fungi, now placed in the family Stachybotryaceae. The genus was erected by August Carl Joseph Corda in 1837. Historically, it was considered closely re ...
Stachybotrys zhangmuensis
''Stachybotrys'' () is a genus of molds, hyphomycetes or asexually reproducing, filamentous fungi, now placed in the family Stachybotryaceae. The genus was erected by August Carl Joseph Corda in 1837. Historically, it was considered closely re ...
Stachybotrys zuckii
''Stachybotrys'' () is a genus of molds, hyphomycetes or asexually reproducing, filamentous fungi, now placed in the family Stachybotryaceae. The genus was erected by August Carl Joseph Corda in 1837. Historically, it was considered closely re ...
''
See also
*
Bioaerosol
Bioaerosols (short for biological aerosols) are a subcategory of particles released from terrestrial and marine ecosystems into the atmosphere. They consist of both living and non-living components, such as fungi, pollen, bacteria and viruses. Comm ...
Mold health issues
Mold health issues refer to the harmful health effects of Mold (fungus), molds ("moulds" in British English) and their mycotoxins.
Molds are ubiquitous in the biosphere, and mold spores are a common component of household and workplace dust. Th ...
*
Sick building syndrome
Sick building syndrome (SBS) is a condition in which people develop symptoms of illness or become infected with chronic disease from the building in which they work or reside. In scientific literature, SBS is also known as building-related illn ...