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the vegetative part of a fungus consisting of a mass of branching threadlike hyphae

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菌糸体

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/06/16 23:13:59」(JST)

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Fungal mycelium

Microscopic view of a mycelium. This image covers a one-millimeter square.

Another microscopic view of a mycelium. Numbered ticks are 230 µm apart.

Oyster mushroom (Pleurotus ostreatus) growing on coffee grounds

Mycelium as seen under a log

Mycelium 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 mycelium are found in and on soil and many other substrates. A typical single spore germinates into a homokaryotic mycelium, which cannot reproduce sexually; when two compatible homokaryotic mycelia join and form a dikaryotic mycelium, that mycelium may form fruiting bodies such as mushrooms. A mycelium may be minute, forming a colony that is too small to see, or it may be extensive:

Is this the largest organism in the world? This 2,400-acre (9.7 km²) site in eastern Oregon had a contiguous growth of mycelium before logging roads cut through it.Estimated at 1,665 football fields in size and 2,200 years old, this one fungus has killed the forest above it several times over, and in so doing has built deeper soil layers that allow the growth of ever-larger stands of trees. Mushroom-forming forest fungi are unique in that their mycelial mats can achieve such massive proportions.

—Paul Stamets, Mycelium Running^[1]

Through the mycelium a fungus absorbs nutrients from its environment. It does this in a two-stage process. First, the hyphae secrete enzymes onto or into the food source, which break down biological polymers into smaller units such as monomers. These monomers are then absorbed into the mycelium by facilitated diffusion and active transport.

Mycelium is vital in terrestrial and aquatic ecosystems for their role in the decomposition of plant material. They contribute to the organic fraction of soil, and their growth releases carbon dioxide back into the atmosphere. Ectomycorrhizal extramatrical mycelium, as well as the mycelium of Arbuscular mycorrhizal fungi increase the efficiency of water and nutrient absorption of most plants and confers resistance to some plant pathogens. Mycelium is an important food source for many soil invertebrates.

"Mycelium", like "fungus", can be considered a mass noun, a word that can be either singular or plural. The term "mycelia", though, like "fungi", is often used as the preferred plural form.

Sclerotia are compact or hard masses of mycelium.

Uses

One of the primary roles of fungi in an ecosystem is to decompose organic compounds. Petroleum products and pesticides, typical soil contaminants, are organic molecules, i.e. they are built on a carbon structure. This means that these substances present a potential carbon source for fungi. Hence, fungi have the potential to remove such pollutants from the soil environment, unless the chemicals prove toxic to the fungus. This biological degradation is a process known as bioremediation.

Mycelial mats have been suggested (see Paul Stamets) as having potential as biological filters, removing chemicals and microorganisms from soil and water. The use of fungal mycelium to accomplish this has been termed mycofiltration.

Knowledge of the relationship between mycorrhizal fungi and plants suggests new ways to improve crop yields.

When spread on logging roads, mycelium can act as a binder, holding new soil in place and preventing washouts until woody plants can be established.

Since 2007, a company called Ecovative Design has been developing alternatives to polystyrene and plastic packaging by growing mycelium in agricultural waste. The two ingredients are mixed together and placed into a mold for 3–5 days to grow into a durable material. Depending on the strain of mycelium used, they make many different varieties of the material including water absorbent, flame retardant, and dielectric.^[2]

Fungi are essential for converting biomass into compost, as they decompose feedstock components such as lignin which many other composting microorganisms cannot.^[3] Turning a backyard compost pile will commonly expose visible networks of mycelia that have formed on the decaying organic material within. Compost is an essential soil amendment and fertilizer for organic farming and gardening. Composting can divert a substantial fraction of municipal solid waste from landfill.^[4]

References

^ Stamets, Paul. Mycelium Running, Ten Speed Press,U.S.A. 2005 (p. 45, caption to figure 60)
^ Kile, Meredith (September 13, 2013). "How to replace foam and plastic packaging with mushroom experiments". Al Jazeera America.
^ "Composting - Compost Microorganisms". Cornell University. Retrieved 17 April 2014.
^ Epstein, Eliot (2011). Industrial Composting: Environmental Engineering and Facilities Management. CRC Press. ISBN 143984531X.

External links

Mycofiltration: A novel approach for the bio-transformation of abandoned logging roads
Paul Stamets: Six ways mushrooms can save the world
The mycelium
Eben Bayer's Talk about Greensulate at the TED conference

UpToDate Contents

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1. ブラストミセス症の菌学、病因、および疫学 mycology pathogenesis and epidemiology of blastomycosis
2. パラコクシジオイデス症の菌類学および疫学 mycology and epidemiology of paracoccidioidomycosis
3. ブラストミセス症の臨床症状および診断 clinical manifestations and diagnosis of blastomycosis
4. スポロトリコーシスの臨床的特徴および診断 clinical features and diagnosis of sporotrichosis
5. 肺ヒストプラスマ症の病因および臨床的特徴 pathogenesis and clinical features of pulmonary histoplasmosis

English Journal

Improved endoglucanase production and mycelial biomass of some ericoid fungi.

Adeoyo OR1, Pletschke BI1, Dames JF2.
AMB Express.AMB Express.2017 Dec;7(1):15. doi: 10.1186/s13568-016-0312-y. Epub 2017 Jan 3.
Fungal species associated with ericaceous plant roots produce a number of enzymes and other bio-active metabolites in order to enhance survival of their host plants in natural environments. This study focussed on endoglucanase production from root associated ericoid mycorrhizal and dark septate endo
PMID 28050856

Hanseniaspora uvarum prolongs shelf life of strawberry via volatile production.

Qin X1, Xiao H2, Cheng X3, Zhou H4, Si L5.
Food microbiology.Food Microbiol.2017 May;63:205-212. doi: 10.1016/j.fm.2016.11.005. Epub 2016 Nov 9.
Gray mold caused by Botrytis cinerea led to severe postharvest losses for strawberry industry. In recent years, some studies have shown that postharvest diseases of strawberry can be controlled by using bacterial, fungal and yeast strains. The yeast strain Hanseniaspora uvarum was shown as an effect
PMID 28040170

Mechanisms of antifungal and anti-aflatoxigenic properties of essential oil derived from turmeric (Curcuma longa L.) on Aspergillus flavus.

Hu Y1, Zhang J2, Kong W3, Zhao G4, Yang M5.
Food chemistry.Food Chem.2017 Apr 1;220:1-8. doi: 10.1016/j.foodchem.2016.09.179. Epub 2016 Sep 29.
The antifungal activity and potential mechanisms in vitro as well as anti-aflatoxigenic efficiency in vivo of natural essential oil (EO) derived from turmeric (Curcuma longa L.) against Aspergillus flavus was intensively investigated. Based on the previous chemical characterization of turmeric EO by
PMID 27855875

Japanese Journal

Analysis of indole compounds from the fruiting bodies and the culture mycelia of Sarcodon imbricatus

Sulkowska-Ziaja Katarzyna,Muszynska Bozena,Ekiert Halina
Mycoscience : official journal of the Mycological Society of Japan 55(3), 164-167, 2014-05
NAID 40020034995

Comparatve Study of Mycelial Growth and Carpophore Yield of Agrocybe aegrerita (Brig.) Sing. on Selected Agricultural and Textile Industry Wastes as a Cultivation Substrate

Jasińska Seung–Yeol,Siwulski Marek,Majtkowski Włodzimierz,Rogalski Jerzy,Ohga Shoji
Journal of the Faculty of Agriculture, Kyushu University 59(1), 5-11, 2014-02-29
… The mycelial growth was the best on straw of Miscanthus gigantheus, Miscanthus sinensis and Miscanthus sacchariflorus. …
NAID 120005397817