Yeast habitat. Yeast fungus and its proper treatment
The kingdom of mushrooms is one of the most unusual and impressive in the world of wildlife. The diversity of these organisms is really impressive, and their properties are worthy of careful study. People encounter some of their species every day, without even thinking about the fact that these are mushrooms. It is on such varieties that it is worth dwelling in more detail.
What are mushrooms?
This kingdom has complex classification. Most people understand only one type of mushrooms, the main one is hat. It includes both edible and poisonous options - champignons, truffles, mushrooms, chanterelles, fly agarics, grebes and many others.
Others, even more interesting view, are fungi. They are microscopic in size, due to which the fruiting bodies and mycelium are almost impossible to notice with the naked eye. But in general, it is not at all difficult to see them - just leave a piece of bread in a humid place, and soon a familiar fluffy coating will appear on it. These are mold fungi, namely saprophytes, an inedible species that often spreads over fruits, vegetables, soil and walls of damp dark rooms.
The third type is yeast. They have been known to man for a long time and are as common as mold fungi. For example, it is to them that people owe the existence of bread, beer, wine and kvass. mold mushrooms and yeast reproduces equally well in the everyday environment for a person, but, unlike the former, which prefer dampness and twilight, the latter need sugar. But there is one thing in common - yeast is also impossible to see in detail without a microscope. To date, a person knows 1500 of their varieties.
yeast mushrooms
This species differs from all others in that it has lost the mycelial structure classic for the kingdom. Yeast lives in a liquid or semi-liquid medium filled with organic matter. They exist as dividing or budding cells. This structure allows them to have the highest possible metabolic rate, so they can grow and multiply quickly. Despite the fact that molds and yeasts seem similar due to their microscopic size, the former still have mycelium and that's it. characteristics, while the latter make up one cell. The history of the origin of the name of this variety is interesting. The word "yeast" refers to the trembling that can be seen in fermented wort or rising dough.
Features of mold fungi
This variety retains most of the properties of cap species. However, they are microscopic in size. Mold fungi form the thinnest branched mycelium, from which large fruiting bodies are not separated. They were the first inhabitants of the planet Earth, on which they appeared more than two hundred million years ago. The mycelium of the mold fungus develops in almost all conditions in nature, regardless of the availability of food and the characteristics of the habitat. Huge colonies instantly appear in the presence of humidity and a sufficiently high temperature.
Kinds mold fungi are very numerous, but they have common features - the mycelium serves as the basis, and thin branching threads are placed right inside the affected surface. Unlike yeast, they reproduce sexually or vegetatively. The mold cell does not make up its entire body. However, this does not prevent them from spreading at a tremendous speed.
The most famous fungi
Some of the representatives of the kingdom are more important to humanity than others. These are penicillium mold fungi, which are green spots that grow on plant substrates and ordinary food products. They produce an antibiotic called penicillin, which was the world's first antibacterial drug. His invention changed the world of medicine. Both molds and bacteria can be harmful to human health. But a species called penicillium can save lives, which has earned its widest fame.
Phycomycetes class
One of the most common species are Phycomycetes, or mucor molds. There are more than three hundred varieties in this family. The three most common are Mucor, Thamnidium and Rhizopus. The structure of mold fungi mukor differs in that their mycelium often consists of a single branched cell. Aerial spherical hyphae filled with many spores depart from it. The spread of mucoral occurs easily and quickly on many types of substrate, with the exception of dairy products, and stops only at temperatures below -8 degrees Celsius.
Ascomycetes class
It is to this family that penicillium fungi belong, as well as some others, for example, the genus Aspergillus. Otherwise, this class is called marsupials. While mucor molds form a primitive unicellular mycelium, ascomycetes are distinguished by a more complex structure, which quickly forms separate colonies that grow along the substrate. Spores are instantly formed on it, to which the mold owes its fluffy appearance of a grayish-green color. When studied under a microscope, the reasons for the name become obvious - the structure of molds includes long chains of conidia containing spores, which form a brush or bag. Ideal conditions for development are dampness and poor ventilation at temperatures close to 0 degrees Celsius.
Difference Aspergillus from Penicillum
Found in the same family, these molds are similar in appearance. They have a colorless mycelium with colored spherical conidia, as a rule, they are distinguished by a grayish-blue or gray-green tint, less often with a yellow undertone. However, the role of aspergillus molds is markedly different. While penicillin serves important component medicines, in a form related to penicillium, contains substances that cause spoilage of dairy or meat products.
imperfect mushrooms
This class has not been studied as extensively as those described above. Imperfect mold species reproduce by a method other than sexual reproduction, not known in detail. They are distinguished by septate mycelium with grape-like spores of dark color. Because of this, the defeat of such mushrooms forms black velvety spots. This mold develops well with low temperatures and is distinguished by a large affected area - when it appears on meat, it penetrates deep into the muscle tissue. It is these fungi that can lead to internal mold, spoil butter, cheese, egg products.
milk mold
Mushrooms of the variety Oidium lactis resemble yeast in their structure. They have a white septate mycelium with separated spores in the form of single cells. The nutrition of molds of this species includes a variety of dairy products. Their appearance is manifested in the form of a fluffy plaque. white color, which can cover the surface of sour cream, curdled milk or cottage cheese. Mold reduces their acidity, causing the product to deteriorate. Some scientists attribute them to yeast due to the simplicity of cell chains and felt-like mycelium.
Mold that grows in the refrigerator
Several varieties of fungi can affect products that are stored at a sufficiently low temperature. First of all, this is Botrytis, which is distinguished by a creeping felt-like mycelium, with colorless conidia appearing in bunches. Molds also include those that are distinguished by brown or olive conidiophores. A similar species develops in the refrigerator at temperatures below 5 degrees Celsius and affects a variety of products. Another dangerous species to eat is Alternaria. These include mushrooms with pear-shaped or pointed conidia of brown or olive color. Such mold can infect not only chilled, but also frozen meat, as well as butter and other food products.
Thomas class
These molds differ from all others in their original structure. They do not form an external mycelium and most often develop inside the substrate, which is undergoing a decay process. To reproduce, Phoma molds use short conidiophores with intertwined hyphae surrounding them like a shell.
How does mold affect the human body?
Not all types of mushrooms are as useful for humanity as penicillium. More often, the situation is quite the opposite, and the appearance of mold is an unkind sign. First of all, its spores have a very negative effect on the mucous membranes of the body, causing immune reactions. This is one of the most strong allergens, and people with certain problems in this area are guaranteed to be uncomfortable at the slightest contact with mold. And it's not just a short-term reaction - over time, everything can end in serious diseases. In houses affected by molds, eight out of ten tenants develop asthma. The number is very impressive. And this is not all possible problems.
If such a problem arises, it is necessary to think about ways to destroy mushrooms as soon as possible. To do this, you should use a special antiseptic, which can be purchased at a building materials store. It is necessary to work with it as carefully as possible, having studied the instructions for use. In addition, before starting the fight against mold, it is worth examining how deeply the surface is affected. Sometimes it is better to throw away an infected item. If the defeat is not so large-scale, you can proceed to action. First of all, pay attention to the antiseptic primer. It will not only kill the mold, but also prevent its reappearance. Using such a tool is quite simple, most often you do not even need to dilute it with water. It is only recommended to clean the surface before treatment.
If there is no opportunity or desire to look for a special remedy, you should turn to home methods. For example, great option may be bleach. The sodium hypochlorite contained in it kills not only mold, but also its spores. Bleach is ideal for when you need to clean bathroom tiles, floors or glass. But for other items, it can be dangerous - many things lose color or deteriorate from such processing. In addition, bleach is quite toxic, so you should only use it in a well-ventilated room, armed with protective rubber gloves.
Vinegar is less dangerous in such cases. It is not so toxic, so it can be used without fear. It is worth using vinegar with a spray bottle or by wetting a rag in it and wiping the surface affected by mold.
For those who do not have such a tool in their arsenal, hydrogen peroxide is suitable. It can be bought at any pharmacy, it is not dangerous to health and does not have a pungent odor. Peroxide can kill mold on a wide variety of surfaces, but be aware of its bleaching effect, which can be harmful to fabrics or paints.
Suitable for hard surfaces like tiles and glass ammonia. Enough in equal proportions mix it with water and spray the mixture over the entire infected area, and rinse it with water after a few hours.
The safest way would be baking soda. It will not harm family members or pets. To combat mold, a teaspoon of soda is dissolved in a glass of water, after which the affected surfaces can be sprayed with the mixture. It is not necessary to wash off the solution - it will be a prophylactic.
Representatives unicellular fungi are, for example, yeast.
About 500 species of yeast fungi are known. yeast mushrooms are found in nature on the surface of plants, in the nectar of flowers, on fruits, in the sap of trees, in the soil. They do not form a typical mycelium. These microscopic fungi consist of a single spherical cell. Yeast reproduces by budding: a protrusion (like a kidney) is formed on the body of the fungus, which increases, separates from the mother's body (buds) and leads an independent lifestyle. Budding yeast cells look like branching chains.
Since ancient times, people have been using yeast to make bread.
Yeast grows rapidly, which is determined by their unusually high metabolic rate. However, they significantly change chemical composition environment. The most famous process they carry out is alcoholic fermentation. Yeast feeds on sugar, turning it into alcohol. At the same time, carbon dioxide is released, which contributes to raising the dough, making it light and porous.
Some yeast mushrooms are used by people in brewing, winemaking and as a protein feed in animal husbandry.
Ascomycete and basidiomycete yeasts
It is possible to distinguish between yeasts belonging to different divisions of fungi both by the characteristics of their life cycle, and without its observation, only by signs of affinity. These include:
- synthesis of carotenoids (found only in basidiomycete yeast);
- type of ubiquinones (with 5-7 isoprenoid residues in ascomycetes and with 8-10 in basidiomycetes, although there are exceptions);
- type of budding (see section life cycle);
- the content of GC pairs in DNA (26-48% in ascomycetes, 44-70% in basidiomycetes);
- the presence of the urease enzyme (characterized with a few exceptions only by basidiomycetes), etc.
Features of yeast metabolism
Yeasts are chemoorganoheterotrophs and use organic compounds both for energy and as a source of carbon. They need oxygen for respiration, but in its absence, many species are able to obtain energy through fermentation with the release of alcohols (facultative anaerobes). Unlike bacteria, there are no obligate anaerobes among yeasts that die in the presence of oxygen in the environment. When air is passed through the fermentable substrate, the yeast stops fermentation and begins to breathe (because this process is more efficient), consuming oxygen and releasing carbon dioxide. This accelerates the growth of yeast cells (Pasteur effect). However, even with the access of oxygen in the case high content glucose in the medium, the yeast begin to ferment it (Crabtree effect).
Cells baker's yeast, fluorescence microscopy.
Yeast is quite demanding on nutritional conditions. Under anaerobic conditions, yeast can only use carbohydrates as an energy source, mainly hexoses and oligosaccharides built from them. Some species (Pichia stipitis, Pachysolen tannophilus, Phaffia rhodozyma) also digest pentoses, such as xylose. Species Schwanniomyces occidentalis and Saccharomycopsis fibuliger are able to ferment starch, species Kluyveromyces fragilis - inulin. Under aerobic conditions (in the presence of oxygen), the range of digestible substrates is wider: in addition to carbohydrates, fats, hydrocarbons, aromatic and one-carbon compounds, alcohols, and organic acids are also digested. Many more species are able to use pentoses under aerobic conditions. Nevertheless, complex connections(lignin, cellulose) are not available for most yeasts (with the exception of some species of the genus Trichosporon, which exhibit cellulolytic activity).
Ammonium salts can be nitrogen sources for all yeasts, about half of the species have nitrate reductase and can absorb nitrates. Urea uptake pathways are different in ascomycetes and basidiomycetes yeasts. Ascomycetes first carboxylate it, then hydrolyze it, basidiomycetes immediately hydrolyse it with the enzyme urease.
For practical application important products of the secondary metabolism of yeast, released in small quantities into the environment: fusel oils, acetoin (acetylmethylcarbinol), diacetyl, butyric aldehyde, isoamyl alcohol, dimethyl sulfide, etc. The organoleptic properties of products obtained with the help of yeast depend on them.
spreading yeast
Yeast habitats are mainly associated with sugar-rich substrates: fruit and leaf surfaces (where yeast feeds on vital plant secretions), flower nectar, plant wound sap, dead phytomass, etc. Yeasts are also common in the soil (especially in the litter and organic horizons ) and natural waters. Yeasts (genera Candida, Pichia, Ambrosiozyma) are constantly present in the intestines and passages of xylophages (wood-eating insects); rich yeast communities develop on leaves affected by aphids. Representatives of the genus Lypomyces are typical soil inhabitants.
Yeast life cycle
A distinctive feature of yeast is the ability to reproduce vegetatively in a unicellular state. When compared with the life cycles of fungi, this looks like budding of spores or zygotes. Many yeasts are also capable of a sexual life cycle (its type depends on affinity), which may include mycelial stages.
In some yeast-like fungi that form mycelium (genera Endomyces, Galactomyces, Arxula, Trichosporon), mycelium can break down into cells (arthrospores). In the genera Arxula and Trichosporon, arthrospores begin to bud after formation. In fungi of the genus Trichosporon, vegetative endospores are also formed inside the cells of the mycelium.
Human life is impossible without microorganisms that bring great benefit. They live nearby, although they are not visible to the naked eye. This article looks at how yeast and other microorganisms reproduce.
Yeast: definition
Yeasts are microorganisms that belong to the fungus family. Their distribution is observed everywhere, they are present even in the air. Yeasts are able to feed. They can produce by-products, reproduce, and also generate energy. Nutrition is sugar, if they are not present, the yeast begins to break down starches. In the process of life of organisms, a by-product is formed - carbon dioxide, which is released in the form of tiny bubbles. They, in turn, are caught by the gluten network, which is a protein substance that flour is rich in.
The shape of yeast cells is oval, ovoid, elliptical, less common cylindrical or rod-shaped, lemon-shaped and pear-shaped. The mass, size, shape of the cells are different. Their parameters are influenced by the habitat and the age of the cells.
Each microorganism has its own way of reproduction. Yeast has several. How do yeast reproduce? This type of unicellular organisms is characterized by such methods as budding and sporulation. But sometimes reproduction occurs as a result of cell division into two parts, that is, in half. To the question of which method of reproduction is characteristic of yeast, the answer is simple - budding. In general, the mode of reproduction is influenced by the conditions of life and the types of unicellular organism.
Reproduction of yeast by budding
How do yeast reproduce? In short - three, but the main one is budding. This method of reproduction is called vegetative and consists in separating the daughter cell from the mother cell. In this case, the yeast is said to reproduce by budding. How does this happen? The mother cell forms a tubercle on its surface, which is called the kidney. Its size increases, and finally it grows. A constriction (channel) separates the kidney and the cell that produces it. It gradually begins to narrow, as a result of which the daughter cell separates, into which the cellular elements from the mother cell pass, but not completely, but part of them.
This method of reproduction is typical for lemon yeast. For its implementation, favorable conditions are needed, under which there will be enough nutrition for the cells, good air access is provided. For the process of yeast propagation, the temperature of 25 ° C is considered optimal. At what rate does yeast multiply? If conditions are favorable, the process can take approximately two hours.
It often happens that the detachment of young cells did not occur, they remained together with the mother. IN this case and the process of budding takes place on them. The result of this division is the formation of a whole cluster of cells connected to each other.
Reproduction of yeast by sporulation
Another way yeast reproduces is by sporulation. Spore formation occurs inside the cell. Their number can be different: from 2 to 12 pieces. How does yeast reproduce? The process can occur in two ways:
- Sexual - sporulation is the result of the fusion of 2 cells.
- Asexual - spores are formed as a result of crushing the cell nucleus into small particles, each of which is surrounded by the substance of the protoplasm and covered by a shell.
yeast spores
In most cases, the spores are round or oval shape. They are more resistant to external factors than vegetative cells. The formation of spores is facilitated by the unfavorable conditions in which the cell lives. For example, there was a sharp transition in nutrition: from good to bad. Since the formation of spores occurs asexually, they also have one set of chromosomes. But there are yeasts (asporogenic) that do not form spores at all.
How do yeast reproduce? This process can occur both by budding and by sporulation. Such yeast are called "true". Some types of yeast do not have the ability to form spores. The process of their reproduction occurs in only one way - by budding. Such yeast was given another name - "false".
How are yeast classified?
Yeast belongs to the class of ascomycetes according to Kudryavtsev's classification. It consists of three families. Yeast cells of families differ in shape, their reproduction occurs in different ways.
- Saccharomyces family. In such yeast, the shape of the cells can be either oval or ovoid. They reproduce vegetatively by budding. Developing in an unfavorable environment, yeast reproduces sexually with the help of ascospores. The biochemical sign of such yeast is the fermentation of sugar. In industry, yeast is used, which is called "cultural". Their development requires acidic environment. Their growth and reproduction will be active under conditions called aerobic. Yeasts are very sensitive to substances dissolved in their habitat, which have a high concentration. In this regard, fermentation is distinguished as top and bottom. So, for example, a high concentration of sugar causes the cessation of the vital activity of yeast.
- Schizosaccharomycetes are a family of yeasts whose cells are rod-shaped. Reproduction occurs by division, and under conditions that are unfavorable for cell development, spore formation occurs. Such yeast causes fermentation, which is called alcohol. They are used in the industry of regions with a warm climate, they are used to produce beer and Kuban rum.
- Sugar family. In such yeast, the shape of the cells is lemon-shaped, reproduction is by budding. These yeasts, like the representatives of the previous family, cause fermentation - alcohol. In the wine industry, they are considered pests due to the formation of products due to which the wine acquires an unpleasant smell.
What is the importance of yeast?
The practical use of yeast is an integral part of the production of bakery products, alcohol. They are used in brewing, as well as for making kvass. The living conditions of yeasts have a strong influence on them, as a result of which some of their varieties have acquired characteristics called isolated. Such yeasts are called "races".
For the manufacture of products, each industry uses its own race. For example, for the production alcoholic beverages you need yeast with a high ability to actively ferment sugar at high temperatures (up to 30 ° C). Beer is prepared using a slow-fermenting race. Baking bread and buns is carried out using a race that multiplies rapidly, accumulates energy and lift. This is why flour products look fluffy.
However, there are yeasts that are harmful to beer production. Developing in the product, they contribute to an unpleasant taste and smell. Such yeasts and yeast-like organisms are not able to form spores. Moreover, their presence spoils the raw materials and the finished product.
mold mushrooms
Their appearance on planet Earth belongs to the distant past: 200 million years ago. Mold has unlimited possibilities. It can take a life from a person, or it can save a person in difficult times. The mold looks very beautiful, but despite this, it is disgusting. This species organisms tend to form branching mycelium, the size of which is microscopic. Mushrooms, as well as similar organisms, are widely distributed in nature.
They develop in any environment, forming large colonies, and settle on a feeding environment. Particularly favorable for the development of fungi is heat as well as high humidity. Notably, mold growth is almost impossible to stop if food is present. Mushrooms are unpretentious to the habitat and food.
Mold mushrooms: structure
This type of microorganisms has many varieties, but they are all characterized by typical features. The basis of the vegetative body is mycelium or mycelium - thin threads (hyphae) that can strongly branch. The location of the hyphae is the surface or the inner part of the substrate in the area of the fungus settlement. Molds, forming mycelium, occupy large areas. The mycelium of lower fungi has a non-cellular structure, while in molds it is divided into cells.
How do fungi reproduce?
Mushrooms and yeast grow different ways. For yeast, budding and sporulation are the main ones, and for fungi, the easiest way is with the help of parts of the mycelium. The mycelium, once in a new area, begins to develop independently, forming a single organism, and the mycelium, immersed in the substrate, provides the mold with moisture, nutrition and substances of mineral origin. On the air part of the mycelium, located above the surface of the substrate, the formation of bodies occurs, due to which the mold fungus multiplies.
Under unfavorable conditions, the fungus can form a dormant stage called sclerotium. These are strong nodules, the surface of which is hard. They are formed by intertwined hyphae. Under favorable conditions, the sclerotium germinates, forming individual bodies intended for reproduction.
There is another resting stage - chlamydospores. Their formation entails the collection of cytoplasm into lumps. This is how a new shell is formed. It is thick and colored. Such hyphae are like a chain. Mold fungi, having a multicellular structure, are highly organized, complex organisms.
bacteria
These are microorganisms that consist of a single cell. Their size reaches 10 microns. In shape, they are divided into rod-shaped, spherical, convoluted. The parameters of bacteria change when the external factors of their habitat change.
How do bacteria, molds, yeast reproduce? Mushrooms reproduce by mycelium, yeast by buds and spores, and bacteria by simple transverse fission asexually, although they can reproduce in other ways. Bacteria rarely reproduce by budding, but sexually it occurs at a primitive level.
Bacterial cells consist of capsules, cytoplasmic membranes, cell walls, cytoplasm, in which ribosomes, mesosomes, inclusions, and nucleoid are located. Some bacterial cells are characterized by the presence of flagella and the formation of spores. Cells differ in the way they feed. According to this feature, bacteria are autotrophs, heterotrophs. Their breathing patterns also differ. In this regard, bacteria are distinguished as aerobes and anaerobes.
How do yeast reproduce? Single-celled organisms - yeast - reproduce in many ways, including cell division. Interesting fact: division of one cell can occur 20-25 times. This means that a single cell is able to create new ones in an amount equal to the number of its division. One generation of cells does not live long, approximately one to seven hours. The duration of its existence is influenced by the environment, as well as the age of the mother cell.
Mold mushrooms. Yeast
By the time the spores mature, the sporangia turn black and the spores spill out. Getting into suitable conditions, the spores germinate and give rise to a new mucor mycelium. This is how asexual reproduction of mucor occurs.When the substrate is depleted, mucor passes to sexual reproduction by the type of gametangiogamy. The hyphae of different mycelia (usually one thread is marked with a "-" sign, considering it male, and the other with a "+" sign, considering it female) come together with swollen ends - gametangia, which are separated from the mycelium by partitions, the membranes between them dissolve, and the cytoplasm and nuclei of different signs merge. A zygote is formed with numerous
nym diploid nuclei, covered with a thick spiny membrane. After a dormant period, the nuclei undergo meiosis, the outer shell of the zygote bursts, and it grows into a short hypha, ending in a small sporangium. In it, as a result of meiotic division, "+" and "-" spores are formed. Vegetative "+" and "-" mycelia develop from these spores.
Mucoraceae take part in the circulation of organic (especially nitrogen-containing) soil substances. They often cause food spoilage. They are used to produce alcoholic beverages (mucor yeast), soy cheese. Some cause lung disease in birds, affect the hearing organs and the central nervous system in humans, cause dermatomycosis.
Class Ascomycetes. Saprotrophic soil and mold fungi that settle on bread, vegetables and other products (Fig. 83). Mycelium haploid, sep-
branched, branched. At first it looks like a white cobweb plaque, and then acquires a greenish or bluish tint. From the mycelium rise up conidiophores, the ends of which form a brush. At the tip of each branch, a chain of rounded spores is formed exogenously - conidium. They are carried by air currents and give rise to a new mycelium. Sexual reproduction is rare. In this case, the gametangia merge and the formation of fruiting bodies containing asci (bags) in which haploid ascospores develop. The formation of fruiting bodies can be detected by the appearance of a lemon-yellow color appearing where the accumulation of fruiting bodies is observed.Saprotrophic species of penicillium mineralize soil organic matter. Some species are used to prepare the antibiotic penicillin. Also used in Food Industry for the preparation of special types of cheese.
Yeasts are characterized by a strongly pronounced aerobic metabolism. They use various sugars, simple and polyhydric alcohols, organic acids and other substances as a carbon source. The ability to ferment carbohydrates by breaking down glucose into ethyl alcohol and carbon dioxide, served as the basis for the introduction of yeast into the culture.
Under favorable conditions (the presence of carbohydrates and desired temperature) yeast long time reproduce vegetatively by budding. The kidney arises at one end of the cell, begins to grow and separates from the mother cell. Often the daughter cell does not lose its connection with the mother cell and begins to form buds on its own. As a result, short chains of cells are formed. However, the connection between them is fragile, and when shaken, such chains break up into separate cells. With a lack of nutrition and an excess of oxygen, the sexual process occurs in the form chologamy- copulation (fusion) of two haploid cells. The resulting zygote turns into a bag, in which 4 ascospores are formed by meiosis, each of which develops into new yeast cells.
cap mushrooms
Class Basidiomycetes. Higher fungi, the vegetative body of which is a branched mycelium, consisting of segmented hyphae. Distinctive feature basidiomycetes - the presence in each cell of the mycelium of two haploid nuclei. Such a cell is called savage, and the mycelium developing from it - dikaryonic.
Most basidiomycetes are characterized by the formation of fruiting bodies. They may look like a film, hoof-shaped outgrowths, but most often they consist of a cap and a leg. They are called mushrooms in everyday life. As a rule, the cap is covered with colored hyphae that form the skin.
The function of fruiting bodies is the formation of spores. On the underside of the cap is a spore-forming layer formed by basidia that alternate with barren fungal filaments. The spore-bearing surface of the cap is called hymenophore. He can be:
© lamellar- has the form of plates, radially diverging from the central lower surface of the cap in the form of rays (russula, chanterelle, mushroom, champignon);
© tubular- has the form of tubes that fit snugly to each other (boletus, boletus, butterdish, boletus).
Due to the formation of plates and tubules, the surface of sporulation significantly increases.
The edges of the plates or the inner surface of the tubes are represented by a layer of basidia. In the basidia, the dikaryon phase of the development of basidiomycetes is completed. The dikaryon nuclei fuse to form a diploid nucleus. It meiotically divides, and the haploid nuclei pass into basidiospores, which form on the surface of the basidium.Sexual reproduction occurs by the type of somatogamy. The haploid basidiospore germinates, forming a primary mononuclear mycelium. When hyphae meet, having a different gender sign ("+" and "-"), the contents of the cell of one hyphae ("-") passes into the cell of another ("+"). Moreover, only the protoplasts of the cells merge, and the nuclei form pairs - dikaryons, which begin to divide synchronously -
sya. As a result, a secondary dikaryonic mycelium is formed (Fig. 85).
| Mushroom nutrition |
| Edible and poisonous mushrooms |
About 200 forms of mushrooms are edible. Most famous White mushroom, boletus, boletus, oiler, champignon, oyster mushroom, camelina, milk mushroom and others. Among inedible mushrooms there are also poisonous ones. The most dangerous are the pale grebe, the red fly agaric, the smelly fly agaric.
Yeasts are fungi that have lost the ability to form mycelium. Yeast does not constitute separate class mushrooms, they do not constitute a separate class, but belong to the 3rd class of higher fungi. 50% of higher fungi are ascomycetes. Yeasts are unicellular fungi. Dimensions - 1-10 microns, average - 5-7 microns. According to their morphology, they are diverse: they can acquire a different shape (oval, cylindrical, sickle-shaped). May form false mycelium.1. Morphology is determined by the type of vegetative propagation:
1.1 Budding. Round, ovoid or oval cells appear. With multiple budding, when the cell is laid down in several parts of the cell, a stellate shape can form. As a result of budding without separation of the kidney from the mother's body and continued budding, false mycelium (genus Candida) appears.
1.2 Budding division. The kidney lays at the base of the cell, as a result of which a pear-shaped (kidney on one side) or fusiform (kidney on both sides) can form.
1.3 Division. Normal division is rare, in this process 1 mother cell gives 2.
2. Asexual reproduction. It is carried out with the help of special cells and spores - ballistospores, endospores. The ballistospore is formed on a special outgrowth - the sterigma, after which it is thrown into the distance. Endospores are laid inside the mother cell (2-10 in 1 cell).
3. Sexual reproduction. They can be carried out in the haploid and diploid phase. Most yeasts are diploid. For everyone there is a type of development.
Development cycle of haploid yeast
Two haploid cells merge with each other, go through the stage of plasmogamy and karyogamy, resulting in the formation of a cycloid zygote. It divides mitotically, fasting - with the help of reduction division. As a result, n-number of ascospores containing a haploid set of chromosomes is formed inside the mother cell. They germinate and give rise to a haploid vegetative cell.
Development cycle of diploid yeast
A vegetative diploid cell undergoes reduction (meiosis). As a result, ascospores containing a haploid set of chromosomes are formed under the maternal membrane. Ascus bursts, haploid ascospores come out and merge with each other. They go through the stage of plasmogamy and karyogamy, resulting in the formation of a diploid zygote. It reproduces by budding and thus restores the population of diploid yeast. 
Yeast classification according to Kudryavtsev (1952)
1. Class Ascomycetes (Ascomycetes).
1 family - Saccharomyceteceae (17 genera), genus Saccharomyces:
- S.cerevisiae (alcohol production, starch processing, bread production);
- S. Carlsbergensis (in breweries);
- S.vini (in winemaking);
- S.minor (to get dark varieties of bread);
2 family Shizoaccharomyceteceae (2 genera), genus Shizoaccharomyces:
- Schizoes pombe (in beer production);
- Sch. Mosquensis (in winemaking);
3 family Saccharomycodaceae (4 genera).
2. Class Fungi imperfecti.
1 family Cryptococcaceae:
- 1 subfamily Cryptococcaideae;
*1 genus Cryptococcus;
* 2 genus Torulopsis (kefir, winemaking);
* 3 genus Candida (BVK, causative agent of mycoses);
* 4 genus Pitorosporum (on human skin);
* 5 genus Brettonomyces (a pest of winemaking);
- 2 subfamily Trichospoiceae (10 genera):
* 1 genus Trichosporon;
- 3rd subfamily Rhodotoruloide:
* 1 genus Rhodotorula.
mold mushrooms
(micromycetes)
These are filamentous microscopic fungi. They form a fluffy coating on the surface from their mycelium. They need a certain humidity, temperature and the presence of a certain substrate. Mycelium deeply penetrates the substrate.
In a systematic sense, mold fungi are heterogeneous and belong to both higher and lower fungi (ascomycetes, fungi imperfecti, lower - zygomycetes). Zygomycetes - r. Mucor, r. Rhizopus.
Characteristic. Mucor - on dense PS forms a felt coating. The body is represented by celocyte mycelium. Hyphae arise from the mycelium - sporangiophores with sporangia, on which spores are formed. Rhizopus - differ from Mucor in that sporangiophores are formed on the mycelium in bunches. 
Folk meaning of mushrooms and yeast
Widely used in biotechnological (b / t) in the production of alcohol, beer, wine, etc. In the baking industry, yeast r. Saccharomyces - used in the form of dry live yeast, which are rich in B vitamins and immunomodulators. R. Candida - protein-vitamin concentrates in animal husbandry. In addition, they receive valuable drugs - vitamin D2, lipids, nucleic acids. Enzymes and coenzymes, as well as organic acids. Molds are producers of organic acids ( lemon acid), antibiotics, etc. Among the fungi there are pests that are pathogenic for humans and animals.
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