por He common mushroom (Agaricus bisporus) is a fungus of the Basidiomycota division that is characterized, among other aspects, by presenting a rounded whitish carpophore and a large number of lamellae in the hymenium. The latter is protected by a veil that breaks when the fungus reaches its full development.
This is the species of mushroom with the highest production worldwide, due not only to its pleasant flavor, but also to its nutritional and medicinal properties, noting that it is low in carbohydrates and rich in B vitamins, potassium, iron, copper and selenium.
In addition to this, it contains substances that can act as aromatase inhibitors, which is why it helps to prevent breast cancer in menopausal women, to keep the prostate healthy, as well as to boost the immune system thanks to its beta-glucans.
The common mushroom has saprophytic habits, therefore it can be cultivated in compost heaps. Under these growing conditions, Agaricus bisporus can be attacked by some pathogens and pests, such as pernicious mycogone, pseudomonas spp, and several species of flies.
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Characteristics
the hat of Agaricus bisporus it is initially globose, but later changes to concave or slightly flattened. This hat can reach up to 18 cm in diameter, but generally does not exceed 13 cm. Its surface is covered by a powdery cuticle on which scales and spots can appear with age.
The hymenium (structure that contains the basidia) presents numerous lamellae that are not attached to the foot. These lamellae have a fleshy consistency and are white or pale pink in color, but later turn dark brown or black when ripe.
The basidia are marginal and bisporic, rather than tetrasporic as is normally the case in the genus agaricus. The spores are slightly purple-brown in color, elliptical to ovoid in shape, smooth, and 5-8 by 4-6 microns in size.
It presents a simple and membranous ring, ascending, which in its youth is attached to the bell and is persistent in the middle or lower part of the foot when mature. It lacks back.
the foot of Agaricus bisporus it is smooth, fibrous, cylindrical, with a height of up to 8 cm long and a diameter of 3 cm, easily detachable from the hat.
taxonomy
The gender agaricus it belongs to the family Agaricaceae, class Agaricomycetes of the Basidiomycota. It was described by Carlos Linnaeus in 1735, to include a great diversity of terrestrial fungi provided with blades and feet. This name was renamed Pratella and later as psalliota.
Currently this genus contains more than 300 species worldwide, some of which, including the common mushroom, are edible, but others are highly poisonous. the species Agaricus bisporus It was described by the Danish mycologist JE Lange and currently has a few varieties.
The most commercialized variety is A. bisporus var hortensiswhich presents a white coloration on its entire surface, with some pink nuances in its meat. Agaricus bisporus var brunnescens is the variety marketed under the names of portobello either crime, depending on its size and stage of development.
commercial importance
The common mushroom is the species with the highest production in the world among cultivated species, with estimated annual volumes of more than 4 million tons for 2009. The main producers are China and France.
These volumes, however, should be underestimated due to the ease of cultivation and few space requirements for it.
artisan cultivation
The common mushroom is easy to grow if its demands for light, humidity, nutrients and temperature are adequately controlled. It can be grown in small orchards isolated from sunlight, and even in bags or boxes. The spores can be purchased in specialized stores.
The interested person can prepare a compost with plenty of decomposing organic matter, horse manure being a good compound for this activity. It must be kept humid but not excessively, to avoid the proliferation of other unwanted organisms. Nor can it receive sunlight.
natural enemies
Different organisms act as pathogens or as pests of the common mushroom. Pathogens include bacteria, as well as fungi and related groups. In turn, its main pests are made up of insects.
Pathogens
The main disease that attacks Agaricus bisporus receives the name of dry bubble and is caused by various species of the genus Verticillum. The vectors are rodents, insects and the human being himself.
pernicious mycogone It is one of the most frequent pathogens, which produces the disease called wet bubble or mole, which causes internal rotting of the fungus.
Other pathogens to highlight are Trichoderma spp., Dactylium spp., Diehliomyces spp., Pseudomonas tolaasii and P. aeruginosa.
pests
The main pests that affect Agaricus bisporus are flies belonging to the species Lycoriella malias well as several species of megaselia and of Mycophila. These insects feed on the fungus and can leave necrotic areas at the site of attack and in the boreholes.
Some species of nematodes can feed on the mycelium of the fungus. The mites can also affect the mushroom, and they can be observed as a reddish dust on the mushroom cap when they are concentrated in that area.
Nutritional properties
Mushrooms are characterized by being very low in carbohydrates, which is why they contribute very few calories to the diet (less than 30 kcal per 100 grams). They are also low in fat, fiber and protein.
Instead they are rich in minerals, such as potassium that helps in nerve transmission and the flow of nutrients in the body; magnesium, which improves cardiovascular health and controls constipation, and selenium, with anticancer properties. It also has iodine, phosphorus, calcium and zinc.
In addition to this, it contains vitamins A, complex B (B2, B3, B1 and folic acid), C, D and E. For all this, mushrooms are good for losing weight, increase the body’s defenses, help control levels of blood sugar, have antioxidant, diuretic, hepatoprotective and anti-anemic properties.
Frequent consumption of mushrooms helps prevent the effects of free radicals, migraines and fluid retention. It also prevents the growth and proliferation of cancer cells and helps regulate intestinal transit and maintain healthy skin, hair and nails.
Aqueous extracts of carpophores have shown anticancer properties, preventing the proliferation of some types of cancer cells by up to 100% in laboratory studies. The mushroom also contains agaritin, a compound with proven carcinogenic properties.
However, the amounts of this compound in mushrooms are so low that 350 grams of fresh mushrooms would need to be consumed daily for a period of 50 years for the risk of developing tumors to be significant.
Reproduction
Basidomycetes generally exhibit both sexual and asexual reproduction. Sexual reproduction involves the formation of basidiospores. In the latter type, only one parent (homothallic, pseudohomothalic) or more than one (heterothallic) may be involved.
Asexual reproduction
In Agaricus bisporicusas in the rest of the Basidomycetes, asexual reproduction can occur by fragmentation of the mycelium.
sexual reproduction
Sexual reproduction in the common mushroom can vary slightly depending on the variety in question. Three taxa are amphithallic, that is, both heterothallic and pseudohomothallic. The reproductive cycle of Agaricus bisporus var. bisporus it is amphithalic with a predominance of pseudohomotalism.
In that subspecies or variety, a sporophore produces a majority of heterokaryotic spores and a small percentage of homokaryotic spores. In A. bisporus var. burnettii contrary to the previous one, there is a predominance towards pseudohomotalism, where the spores are mostly homokaryotic.
Agaricus bisporus var. eurotetrasporus it is homothallic. The mycelium and sporophore are haploid, with gametic fusion and meiosis taking place in the basidium from identical nuclei.
Lifecycle
A basidiospore germinates to produce a haploid primary mycelium, then a pair of mycelia of a different reproductive type (or two hyphae from a mycelium if it is a homothallic variety) fuse, resulting in a secondary mycelium in which karyogamy does not occur.
The secondary mycelium grows in the soil and when conditions are optimal, it develops the fruiting body that emerges from the soil. This fruitful body (carpophore) is formed by the foot and the cap or crown. At the bottom of the hat is the hymenium with hundreds of lamellae, where the basidia will be aligned.
After a few days, the two nuclei of each basidium fuse to produce a diploid zygote, which rapidly undergoes meiosis to form haploid spores. Two spores will be produced in each basidium, which is characteristic and gives rise to the name of the species.
Nutrition
Agaricus bisporus It is a saprophytic species and feeds on decomposing organic matter, for which it releases a series of enzymes that allows it to digest said organic matter and then absorb it. In cultivation, this type of feeding of the fungus is used by cultivating it directly in compost heaps.
A combination that is suitable for growing these mushrooms contains oat, barley or wheat straw, sawdust, sandy soil and horse manure.
References
Agaricus bisporus. On Wikipedia. Retrieved from: en.wikipedia.org.
MA Calvo Torras, M. Rodríguez & L. Domínguez (2011). Agaricus bisporus: cultivation, problems and prevention. Annals of the Royal Academy of Doctors of Spain.
SP Wasser (2000). A contribution to the taxonomy and species diversity of the Agariceae tribe (Higher Basidiomycetes) of Israel mycobiota. Mediterranean Flora.
Mushroom. In Educational Nature. Retrieved from: natureduca.com.
W. Breene (1990). Nutritional and medicinal value of special mushrooms. Journal of Food Products.
G. Mata, R. Medel, P. Callac, C. Billette & R. Garibay-Orijeld (2016). first record of Agaricus bisporus (Basidiomycota, Agaricaceae) wild in Tlaxcala and Veracruz, Mexico. Mexican Magazine of Biodiversity.
V. Gomez. Basidiomycetes: characteristics, nutrition, habitat and reproduction. Recovered from .com.