Microfungi are fungi, eukaryotic organism

Organism

In biology, an organism is any contiguous living system . In at least some form, all organisms are capable of response to stimuli, reproduction, growth and development, and maintenance of homoeostasis as a stable whole.An organism may either be unicellular or, as in the case of humans, comprise...

s such as mold

Mold

Molds are fungi that grow in the form of multicellular filaments called hyphae. Molds are not considered to be microbes but microscopic fungi that grow as single cells called yeasts...

s, mildew

Mildew

Mildew refers to certain kinds of molds or fungi.In Old English, it meant honeydew , and later came to mean mildew in the modern sense of mold or fungus....

s and rust

Rust (fungus)

Rusts are plant diseases caused by pathogenic fungi of the order Pucciniales. About 7800 species are known. Rusts can affect a variety of plants; leaves, stems, fruits and seeds. Rust is most commonly seen as coloured powder, composed off tiny aeciospores which land on vegetation producing...

s, which exhibit tube tip-growth and have cell walls composed of chitin

Chitin

Chitin n is a long-chain polymer of a N-acetylglucosamine, a derivative of glucose, and is found in many places throughout the natural world...

, a polymer of N-acetylglucosamine

N-Acetylglucosamine

N-Acetylglucosamine is a monosaccharide derivative of glucose. It is an amide between glucosamine and acetic acid...

. The microfungi are an artificial, paraphyletic group, distinguished from macrofungi only by the absence of a large, multicellular fruiting body. Microfungi are ubiquitous in all terrestrial and freshwater and marine environments. Microfungi grow in plants, soil, water, insects, cattle rumens

Rumen

The rumen, also known as a paunch, forms the larger part of the reticulorumen, which is the first chamber in the alimentary canal of ruminant animals. It serves as the primary site for microbial fermentation of ingested feed...

, hair, and skin. Most of the fungal body consists of microscopic threads, called hyphae, extending through the substrate in which it grows. The mycelia of microfungi produce thousands of tiny spore

Spore

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 that are carried by the air, spreading the fungus.

Many Microfungi species are benign, existing as soil saprotrophs, for example, largely unobserved by humans. Many thousands of microfungal species occur in lichen

Lichen

Lichens are composite organisms consisting of a symbiotic organism composed of a fungus with a photosynthetic partner , usually either a green alga or cyanobacterium...

s, forming symbiotic

Symbiosis

Symbiosis is close and often long-term interaction between different biological species. In 1877 Bennett used the word symbiosis to describe the mutualistic relationship in lichens...

 relationships with algae

Algae

Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...

. Other microfungi, such as those of the genera Penicillium

Penicillium

Penicillium is a genus of ascomycetous fungi of major importance in the natural environment as well as food and drug production. Members of the genus produce penicillin, a molecule that is used as an antibiotic, which kills or stops the growth of certain kinds of bacteria inside the body...

, Aspergillus

Aspergillus

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...

and Neurospora

Neurospora

Neurospora is a genus of Ascomycete fungi. The genus name, meaning "nerve spore" refers to the characteristic striations on the spores that resemble axons....

, were first discovered as molds causing spoilage of fruit and bread.

Certain species are of value to man. Penicillium species are used in the manufacture of blue cheese

Blue cheese

Blue cheese is a general classification of cow's milk, sheep's milk, or goat's milk cheeses that have had cultures of the mold Penicillium added so that the final product is spotted or veined throughout with blue, blue-gray or blue-green mold, and carries a distinct smell, either from that or...

s and as the source of the antibiotic

Antibiotic

An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...

 penicillin

Penicillin

Penicillin is a group of antibiotics derived from Penicillium fungi. They include penicillin G, procaine penicillin, benzathine penicillin, and penicillin V....

, discovered by Sir Alexander Fleming

Alexander Fleming

Sir Alexander Fleming was a Scottish biologist and pharmacologist. He wrote many articles on bacteriology, immunology, and chemotherapy...

 in 1928, while fusarium venenatum

Fusarium venenatum

Fusarium venenatum is a microfungus of the genus Fusarium that has a high protein content. One of its strains is used commercially for the production of the single cell protein mycoprotein....

 is used to produce a mycoprotein

Mycoprotein

Mycoprotein is defined in the Oxford English Dictionary as: "the albuminoid which is the principal constituent of the protoplasm of the cell." "Myco" is from the Greek word for "fungus"....

 food product.

Harmful microfungi

Microfungi can also be harmful, causing diseases of plants, animals and humans with varying degrees of severity and economic impact. The irritating human skin disease known as athlete's foot

Athlete's foot

Athlete's foot is a fungal infection of the skin that causes scaling, flaking, and itch of affected areas. It is caused by fungi in the genus Trichophyton and is typically transmitted in moist areas where people walk barefoot, such as showers or bathhouses...

 or tinea pedis is caused by species of the microfungal genus Trichophyton

Trichophyton

The fungus genus Trichophyton is characterized by the development of both smooth-walled macro- and microconidia. Macroconidia are mostly borne laterally directly on the hyphae or on short pedicels, and are thin- or thick-walled, clavate to fusiform, and range from 4 to 8 by 8 to 50 um in size....

. Microfungi may cause diseases of crops and trees which range in severity from mild to disastrous, and in economic importance from beneficial to seriously costly. The mould Botrytis cinerea

Botrytis cinerea

Botrytis cinerea is a necrotrophic fungus that affects many plant species, although its most notable hosts may be wine grapes. In viticulture, it is commonly known as botrytis bunch rot; in horticulture, it is usually called grey mould or gray mold.The fungus gives rise to two different kinds of...

can cause spoilage of crops including grapes, but is also responsible for the "noble rot

Noble rot

Noble rot is the benevolent form of a grey fungus, Botrytis cinerea, affecting wine grapes. Infestation by Botrytis requires moist conditions, and if the weather stays wet, the malevolent form, "grey rot", can destroy crops of grapes...

", which concentrates sugars in the grapes used to make the intensely sweet and concentrated Sauternes

Sauternes (wine)

Sauternes is a French sweet wine from the Sauternais region of the Graves section in Bordeaux. Sauternes is made from Sémillon, Sauvignon Blanc, and Muscadelle grapes that have been affected by Botrytis cinerea, also known as noble rot. This causes the grapes to become partially raisined,...

 dessert wines from the Bordeaux

Bordeaux

Bordeaux is a port city on the Garonne River in the Gironde department in southwestern France.The Bordeaux-Arcachon-Libourne metropolitan area, has a population of 1,010,000 and constitutes the sixth-largest urban area in France. It is the capital of the Aquitaine region, as well as the prefecture...

 region of France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

. The potato famine

Potato famine

Potato famine may refer to:* Great Famine , the famine in Ireland between 1845 and 1852* Highland Potato Famine, a major agrarian crisis in the Scottish Highlands from 1846 to 1857...

 in Ireland

Ireland

Ireland is an island to the northwest of continental Europe. It is the third-largest island in Europe and the twentieth-largest island on Earth...

 during the mid-to-late 19th century was caused by a fungus called Phytophthora infestans

Phytophthora infestans

Phytophthora infestans is an oomycete that causes the serious potato disease known as late blight or potato blight. . Late blight was a major culprit in the 1840s European, the 1845 Irish and 1846 Highland potato famines...

that rotted the potato crops for several years. Dutch elm disease

Dutch elm disease

Dutch elm disease is a disease caused by a member of the sac fungi category, affecting elm trees which is spread by the elm bark beetle. Although believed to be originally native to Asia, the disease has been accidentally introduced into America and Europe, where it has devastated native...

, which has ravaged elm

Elm

Elms are deciduous and semi-deciduous trees comprising the genus Ulmus in the plant family Ulmaceae. The dozens of species are found in temperate and tropical-montane regions of North America and Eurasia, ranging southward into Indonesia. Elms are components of many kinds of natural forests...

s across Europe and North America in the last 50 years, is caused by the microfungi of the genus Ophiostoma

Ophiostoma

Ophiostoma is a genus of fungi within the Ophiostomataceae family.Ophiostoma includes the following species:* Ophiostoma carpenteri Hausner, Eyjólfsdóttir, and Reid, 2003, an ophiostomatoid fungus closely related to Ophiostoma retusum Hausner et al. named in honor of Dr. Steven E...

. Rice blast, a devastating fungal disease of cereal

Cereal

Cereals are grasses cultivated for the edible components of their grain , composed of the endosperm, germ, and bran...

s including rice

Rice

Rice is the seed of the monocot plants Oryza sativa or Oryza glaberrima . As a cereal grain, it is the most important staple food for a large part of the world's human population, especially in East Asia, Southeast Asia, South Asia, the Middle East, and the West Indies...

, wheat

Wheat

Wheat is a cereal grain, originally from the Levant region of the Near East, but now cultivated worldwide. In 2007 world production of wheat was 607 million tons, making it the third most-produced cereal after maize and rice...

 and millet

Millet

The millets are a group of small-seeded species of cereal crops or grains, widely grown around the world for food and fodder. They do not form a taxonomic group, but rather a functional or agronomic one. Their essential similarities are that they are small-seeded grasses grown in difficult...

, is caused by the phytopathogenic

Phytopathology

Plant pathology is the scientific study of plant diseases caused by pathogens and environmental conditions . Organisms that cause infectious disease include fungi, oomycetes, bacteria, viruses, viroids, virus-like organisms, phytoplasmas, protozoa, nematodes and parasitic plants...

 Ascomycete fungus Magnaporthe grisea

Magnaporthe grisea

Magnaporthe grisea, also known as rice blast fungus, rice rotten neck, rice seedling blight, blast of rice, oval leaf spot of graminea, pitting disease, ryegrass blast, and Johnson spot, is a plant-pathogenic fungus that causes an important disease affecting rice. It is now known that M...

. In the built environment

Built environment

The term built environment refers to the human-made surroundings that provide the setting for human activity, ranging in scale from personal shelter and buildings to neighborhoods and cities that can often include their supporting infrastructure, such as water supply or energy networks.The built...

, the toxic fungus Stachybotrys chartarum

Stachybotrys chartarum

Stachybotrys chartarum, also called Stachybotrys atra, Stachybotrys alternans or Stilbospora chartarum, is a black mold that produces its conidia in slime heads. It is sometimes found in soil and grain, but mostly isolated from cellulose-rich building materials in damp or water-damaged buildings. S...

causes damage to damp walls and furnishings, and may be responsible for sick building syndrome

Sick building syndrome

Sick building syndrome is a combination of ailments associated with an individual's place of work or residence. A 1984 World Health Organization report into the syndrome suggested up to 30% of new and remodeled buildings worldwide may be linked to symptoms of SBS...

.

Types of epidermal microfungal infections are:

• Yeast infection
• Athlete's foot
  Athlete's foot
  Athlete's foot is a fungal infection of the skin that causes scaling, flaking, and itch of affected areas. It is caused by fungi in the genus Trichophyton and is typically transmitted in moist areas where people walk barefoot, such as showers or bathhouses...
  
  
• Mycosis
  Mycosis
  A mycosis is a fungal infection of animals, including humans. Mycoses are common, and a variety of environmental and physiological conditions can contribute to the development of fungal diseases...
  
  
• Tinea
  Tinea
  Tinea is a general term used to describe skin mycoses. The term ringworm is even less precise, but is usually considered a synonym.It is sometimes equated with dermatophytosis, and it is true that most conditions identified as "tinea" are members of the imperfect fungi that make up the dermatophytes...
  
  
• Candida
  Candida (genus)
  Candida is a genus of yeasts. Many species are harmless commensals or endosymbionts of animal hosts including humans, but other species, or harmless species in the wrong location, can cause disease. Candida albicans can cause infections in humans and other animals, especially in immunocompromised...
  
  

Diversity

Within the United States, approximately 13,000 species of microfungi on plants or plant products are thought to exist. Specimens of microfungi are housed in the U.S. National Fungus Collections and other institutions that serve as reservoirs of information and documentation about our nation's natural heritage. Based on the number of species reported in the literature and those represented in the collections; the number of microfungi known in the United States is estimated at 29,000 species. In areas of the world where fungi have been well studied, the ratio of vascular plant

Vascular plant

Vascular plants are those plants that have lignified tissues for conducting water, minerals, and photosynthetic products through the plant. Vascular plants include the clubmosses, Equisetum, ferns, gymnosperms and angiosperms...

s to fungi is about 6 to 1 . This suggests that there may be as many as 120,000 species of fungi within the United States and 1.5 million worldwide.

See also

• Mycelium
  Mycelium
  thumb|right|Fungal myceliaMycelium is the vegetative part of a fungus, consisting of a mass of branching, thread-like hyphae. The mass of hyphae is sometimes called shiro, especially within the fairy ring fungi. Fungal colonies composed of mycelia are found in soil and on or within many other...
  
  
• Hyphae
• Vascular tissue
  Vascular tissue
  Vascular tissue is a complex conducting tissue, formed of more than one cell type, found in vascular plants. The primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally. There are also two meristems associated with vascular tissue:...
  
  
• 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...
  
  
• Yeast
  Yeast
  Yeasts are eukaryotic micro-organisms classified in the kingdom Fungi, with 1,500 species currently described estimated to be only 1% of all fungal species. Most reproduce asexually by mitosis, and many do so by an asymmetric division process called budding...
  
  
• Dutch elm disease
  Dutch elm disease
  Dutch elm disease is a disease caused by a member of the sac fungi category, affecting elm trees which is spread by the elm bark beetle. Although believed to be originally native to Asia, the disease has been accidentally introduced into America and Europe, where it has devastated native...
  
  
• Rice blast