Hierarchy of mushrooms. Classification of mushrooms, main classes and features
General characteristics. Mushrooms are a kingdom of living organisms that combine the characteristics of plants and animals.
Brings them closer to plants - . 1) the presence of a well-defined cell wall; 2) immobility in a vegetative state; 3) reproduction by spores; 4) ability to synthesize vitamins; 5) absorption of food by absorption (adsorption). Common to animals is: 1) heterotrophy; 2) the presence of chitin in the cell wall, characteristic of the exoskeleton of arthropods; 3) absence of chloroplasts and photosynthetic pigments in the cells; 4) accumulation of glycogen as a reserve substance; 5) formation and release of a metabolic product - urea. These structural features and vital functions of fungi allow us to consider them one of the most ancient groups of eukaryotic organisms that do not have a direct evolutionary connection with plants, as previously thought. Fungi and plants arose independently of the different forms of microorganisms that lived in water.
More than 100 thousand species of mushrooms are known, and it is assumed that the real number is much higher - 250-300 thousand or more. More than a thousand new species are described every year around the world. The vast majority of them live on land, and they are found almost everywhere where life can exist. It is estimated that in the forest litter 78-90% of the biomass of all microorganisms is accounted for by the fungal mass (approximately 5 t/ha).
The place of mushrooms in the organic world In the history of the development and formation of biology, the question of determining the place of mushrooms among other biological objects was controversial until recently. Taxonomists and florists involved in biodiversity have always considered fungi with reservations as part of the plant kingdom, in the subdivision of Tallophyta, as a special class of plants, along with bacteria, lichens, and algae. In the second half of the twentieth century. Works appeared that provided an analysis of modern knowledge about the structure and similarity of the evolution of cell ultrastructures of living organisms. Based on this, Whittaker (1969) proposed a system organic world, including five kingdoms. It adopts an independent kingdom of fungi (Fungi), separate from the kingdoms of animals (Animalia) and plants (Plantae). Thus, only in the second half of the twentieth century. The position about the phylogenetic independence of fungal organisms becomes generally accepted. It turned out that all living organisms on Earth are built according to a single plan. The most important ultrastructures of eukaryotic organisms include several organelles: karyotes, mitochondria, cilia (flagella, undulopodia) and photosynthetic plastids. The features of their structure, role in the life support and evolution of organisms turned out to be the most significant features and were subsequently used as the basis for the mega-systematics of all eukaryotes. In subsequent years, a large number of kingdoms and divisions within them were proposed. In addition, numerous theories have been developed and continue to be developed evolutionary development biota. One of them - the theory of the symbiogenetic origin of the eukaryotic cell through the gradual symbiosis of microbial associations - gave impetus to the construction of numerous schemes of the organic world. The five-kingdom system of structure of the organic world seems to be the most accessible: I. Superkingdom prenuclear organisms, or prokaryotes (Procariota) 1. Kingdom Monera (Monera) II. Superkingdom nuclear organisms, or eukaryotes (Eucariota) 2. Kingdom of protista (Protoctista) 3. Kingdom of fungi (Fungi) 4. Kingdom of animals (Animalia) 5. Kingdom of plants (Plantae) The evolution of microbial associations has led to the difference between eukaryotic cells ( protists, fungi, plants and animals) and prokaryotic cells lacking a true nucleus are deeper than between the listed groups of eukaryotes. The world was divided into two parts, a fundamental distinction occurred in living nature - the distinction between prokaryotes and eukaryotes.
Principles of classification of mushrooms.
Mushrooms belong to the kingdom Fungi(Mycetes, Mycota). These are multicellular or unicellular non-photosynthetic (chlorophyll-free) eukaryotic microorganisms with a cell wall.
Classification of mushrooms. Mushrooms can be divided into 7 classes: chytridiomycetes, hyphochytridiomycetes, oomycetes, zygomycetes, ascomycetes, basidiomycetes, deuteromycetes.
Among phycomycetes distinguish:
1) chytridiomycetes, or aquatic fungi that lead a saprophytic lifestyle or infect algae;
2)hyphochytridiomycetes, having similarities with chytridiomycetes and oomycetes;
4) zygomycetes include representatives of the genus Mucor, widespread in soil and air and capable (for example, fungi of the genus Mucor) of causing mucormycosis of the lungs, brain and other organs.
At asexual reproduction is formed on the fruiting hyphesporangioenosis sporangium- spherical thickening with a shell containing numerous spores (sporangiospores).
Sexual reproduction (oogamy) in zygomycetes they are carried out by the formation zygospore or oospore.
Eumycetes are represented by ascomycetes and basidiomycetes (perfect mushrooms), and deuteromycetes(imperfect mushrooms). Ascomycetes(or marsupial fungi) comprise a group of fungi that have septate mycelium and are distinguished by their ability to reproduce sexually. Ascomycetes got their name from main fruiting organ - bags, or asuka containing 4 or 8 haploid sexual spores (ascospores). Ascomycetes include representatives of the genera Aspergillus, Penicillium and others, differing in the peculiarities of the formation of fruiting hyphae.
U Aspergillus(leach mold) at the ends of the fruiting hyphconidiophores there are thickenings - sterigmata, on which chains of spores - conidia are formed. Some Aspergillus species can cause aspergillosis and aflatoxicosis.
Fruiting hypha in fungi of the genus Penicillium(tassel) resembles a brush, since thickenings are formed from it (on the conidiophore), branching into smaller structures - sterigmata, on which there are chains of conidia. Penicillium can cause diseases (penicillinosis). Many species of ascomycetes are producers of antibiotics.
Representatives of ascomycetes are yeast- unicellular fungi that have lost the ability to form true mycelium. Yeast has oval-shaped cells with a diameter of 3-15 microns. They reproduce by budding, binary fission(divided into two equal cells) or sexual intercourse with the formation of ascospores. Yeast is used in biotechnological processes. Diseases caused by certain types of yeast are called yeast mycoses.
Basidiomycetes - cap mushrooms with septate mycelium.
Deuteromycetes - imperfect mushrooms(Fungi imperfecti) - are a conditional class of fungi, uniting mushrooms with septate mycelium, without sexual reproduction. They reproduce only asexually, forming conidia. Imperfect fungi include fungi of the genus Candida, affecting the skin, mucous membranes and internal organs (candidiasis). They have an oval shape, a diameter of 2-5 microns; They divide by budding (blastospores), form pseudomycelium (budding cells from the germ tube are extended into a thread), at the ends of which there are chlamydospores. These fungi are called yeast-like. True yeasts (ascomycetes) form ascospores and do not have pseudomycelium or chlamydospores. The vast majority of fungi that cause diseases in humans (mycoses) are imperfect fungi.
Mushrooms were classified as lower plants until the end of the 20th century. In 1970, they were finally separated into a separate kingdom, Mushrooms, because have a number of characteristics that distinguish them from plants and bring them closer to animals.
general characteristics
The kingdom fungi are unicellular and multicellular organisms. Currently, taxonomists have counted more than 100 thousand species of fungi.
Fungi are heterotrophic organisms that do not have chlorophyll. They occupy an intermediate position between animals and plants, as they are characterized by a number of properties that bring them closer to animals and plants.
Common signs of fungi and animals:
- The cell membrane contains chitin;
- they accumulate glycogen rather than starch as a reserve product;
- as a result of the exchange, urea is formed;
- absence of chloroplasts and photosynthetic pigments;
General characteristics of mushrooms and plants:
- Unlimited growth;
- absorptive nutrition, i.e. not swallowing food, but absorption;
- the presence of a pronounced cell wall;
- reproduction by spores;
- immobility;
- ability to synthesize vitamins.
Mushroom nutrition
Many species of the kingdom of Fungi live in cohabitation (symbiosis) with algae and higher plants. Mutually beneficial cohabitation mushroom mycelium with roots higher plants forms mycorrhiza (for example, boletus with birch, boletus with aspen).
Many higher plants (trees, durum wheat, etc.) cannot grow normally without mycorrhiza. Fungi receive oxygen, root secretions, and compounds that do not contain nitrogen from higher plants. Fungi “help” higher plants absorb hard-to-reach substances from humus, activating the activity of enzymes in higher plants, promote carbohydrate metabolism, fix free nitrogen, which is used in a number of compounds by higher plants, provide them with growth substances, vitamins, etc.
The kingdom Mushrooms are conventionally divided into lower and higher. The basis of the vegetative body of mushrooms is the mycelium, or mycelium. Mycelium consists of thin threads, or hyphae, similar to fluff. These threads are located inside the substrate on which the fungus lives.
Most often, the mycelium occupies a large surface. Through mycelium Nutrients are absorbed osmotically. The mycelium of lower fungi is either divided into cells or there are no intercellular partitions.
Mono- or multinucleated fungal cells are in most cases covered with a thin cell membrane. Underneath it is a cytoplasmic membrane that envelops the cytoplasm.
The fungal cell contains enzymes, proteins and organelles (lysosomes) in which proteins are broken down by proteolytic enzymes. Mitochondria are similar to those of higher plants. Vacuoles contain reserve nutrients: glycogen, lipids, fatty acids, fats, etc.
Edible mushrooms contain many vitamins and mineral salts. Approximately 50% of the dry mass of mushrooms is nitrogenous substances, of which proteins account for about 30%.
Fungi reproduce asexually:
- Specialized cells - spores;
- vegetatively - parts of mycelium, budding.
The process of sporulation may be preceded by the sexual process, which is very diverse in fungi. A zygote can be formed as a result of the fusion of somatic cells specialized for gametes and germ cells - gametes (formed in the genital organs - gametangia). The resulting zygote germinates immediately or after a period of dormancy and gives rise to hyphae with sexual sporulation organs, in which spores are formed.
Controversy various mushrooms spread by insects, various animals, humans and air currents.
The importance of mushrooms in nature and human life
Molds settle on food, soil, vegetables and fruits. They cause spoilage of benign products (bread, vegetables, berries, fruits, etc.). Most of these fungi are saprophytes. However, some molds are causative agents of infectious diseases in humans, animals and plants. For example, the fungus trichophyton causes ringworm in humans and animals.
Everyone is well aware of the single-celled fungus mucor, or white mold, which settles on vegetables, bread and horse manure. Initially, white mold has a fluffy coating, and over time it turns black, as rounded heads (sporangia) are formed on the mycelium, in which a huge number of dark-colored spores are formed.
Antibiotics are obtained from a number of mold genera (penicillin, aspergillus).
The structure of mushrooms
The vegetative body of the fungus consists of individual threads (hyphae), which intertwine to form mycelium. Mycelium hyphae have a multicellular structure, thickness from 1 to 15 microns and different colors: white, yellowish, bluish. As they age they become gray, olive or Brown color. The hyphae grow at their tips and have lateral branching. Thus, the mycelium is able to grow radially in all directions. Most cap mushrooms the mycelium is perennial and is located in top layer soil, at a depth of 10-15 cm, which is due to the presence of nutrients and the bulk of the roots of woody and herbaceous plants and largely protects the mycelium from unfavorable external conditions. The average growth per year for cap mushrooms is 10-20 cm, sometimes reaching 50 cm, and the age can range from 10 to 25 years or more.
At certain times of the year and under favorable conditions, individual sections of the thythmycelium become denser and form small tubercles (primordia), which, when enlarged, form the fruiting body of the fungus.
Fruiting bodies are, in fact, the reproductive organs of fungi. In caps, they consist of a cap and a stem. The cap contains pulp, hymenophore and hymenium. Each of the listed parts of the fruiting body in individual mushrooms may have a different structure and its own characteristic features, without knowledge of which it is impossible to identify one or another type of mushroom. Mushroom caps can be very different in shape (Fig. 1): hemispherical, convex, flat, concave, conical, etc. The edge of the cap of many mushrooms is initially turned down, but as the fruiting body develops it becomes straight or raised, smooth or wavy curved, whole or dissected.
The skin of the cap can easily separate from the flesh or become attached to it. According to its structure and condition, it can be smooth, scaly, hairy, mucous, wet or dry. There are caps of a wide variety of colors: yellow, red, brown, purple, white, orange, etc. [Tsiryulik‚ Shevchenko, 1989].
The cap flesh consists of thin-walled hyphae of the same type; Less common are thick-walled, convoluted hyphae filled with liquid (milky sap). Such pulp is typical for milk mushrooms, saffron milk caps, and trumpet mushrooms. In the pulp of the fruiting bodies of russula, between the hyphae there are groups of rounded vesicular cells (spherocysts), which give the mushrooms special fragility and fragility.
Mushrooms differ from each other not only in structure, but also in color, smell and taste of the pulp. Most often the color is dim - whitish, brownish-whitish, sometimes with a blue or purple tint. In some mushrooms, the color of the pulp may change when cut.
For example, the flesh of boletus and flywheel turns blue due to the oxidation of pigments by air oxygen. The smell of the pulp can be floury, herring due to the presence of trimethylamine, as well as rare, garlicky, and fruity. Mushrooms can smell like damp earth, wet sawdust, wood, coumarin, anise, etc. The taste of the pulp can be bitter, peppery and pungent, and, conversely, soft - sweetish-nutty or vaguely tasteless, non-caustic.
The main purpose of the pulp is to attach and protect the hymenophore, provide moisture and nutrients basidiospores.
The hymenophore of the caps is most often presented in the form of plates (lamellar mushrooms) and tubes (tubular mushrooms). The plates can be frequent, narrow, thin, less often thick, wide, sparse. The tissue of the plates (trama) is sterile and, depending on the location of the hyphae in it, it can be regular (the hyphae are located in parallel), irregular (the hyphae are located indefinitely) or bilateral (the hyphae diverge evenly on both sides of the central bundle). Hymenophore tubes can be round, oval, angular in shape, and small or large in size. They can be easily separated from each other and from the pulp.
In the hymenial layer covering the thymenophore, there are elongated cells (basidia), on the special outgrowths of which (sterigmata) basidiospores are formed, ensuring the reproduction of fungi (Fig. 2). Between the individual basidia there are larger sterile cells of various shapes (cystids, basidioles or paraphyses), which play a protective role.
Thanks to special structure hymenophora, the spore-bearing surface of the fruiting bodies of lamellar mushrooms increases 7 (russula) - 18 (champignons) times; in tubular mushrooms this increase is even more pronounced. Depending on the type of fungus, one or several generations of basidiospores may mature in the hymenium. This determines the lifespan of the fruiting bodies. For example, in fruiting bodies dung beetles, only one generation of spores matures, and their fruiting bodies last only a few hours, maximum 1-2 days. The lifespan of boletus, chanterelle, valuuya, and honey mushroom is about 10 days; porcini mushrooms, boletus 10-14 days; champignons - 35-40 days.
Important species characteristic mushrooms is also the structure and appearance legs. In shape it can be cylindrical, tuberous, obverse-club-shaped; narrowed upward, downward, or at both ends (Fig. 3). The tissue of the leg is represented by a dense plexus of typhus, which gives it strength. In some mushrooms (for example, boletus), the stem becomes very coarse as it develops. The surface of the leg can be bare, smooth, rough, fibrous, scaly. The flesh of the leg can be solid, tubular, hollow, dense, fragile, springy-elastic.
The structure of the stem of individual types of mushrooms depends on the characteristics of the development of fruiting bodies. Thus, in some mushrooms (fly agarics, floats, volvariella), young fruiting bodies are surrounded by a special plexus of mycelial hyphae, called a common veil (Fig. 4). As the mushrooms develop, the veil breaks, but remains at the base of the stem in the form of a sac-like formation (volva), and on the cap or along its edge in the form of torn shreds and flakes. Another type of bedspread can also form - a private one, which connects the edge of the cap with top part legs. When it ruptures, a ring remains on the stem, as, for example, in boletus mushrooms, wet mushrooms, and umbrella mushrooms.
In addition to the listed structural features of fungi, the structural features of the spores, their size, shape, and color are important for species identification. The shape of the spores can be spherical, angular, tshmonoid, fusiform, star-shaped, oval-ellipsoidal, etc. In color - colorless, pink, rusty or ocher-brown, purple or violet-brown, black-brown, black. The surface of the spores can be smooth, tuberous, prickly, warty, ribbed, etc. The spores are quite resistant to adverse external factors ( low temperatures, drying, etc.)‚ but are very sensitive to elevated temperatures.
The development of fungi, as a rule, begins with the germination of spores, but for this it is necessary to external environment there must be a sufficient amount of moisture, and the soil temperature should not be lower than 3-5 °C.
Classification
Fungi are lower spore plants that lack chlorophyll. The mycelium (mycelium) consists of many intertwined threads - hyphae. It can grow in the ground over a large area. On the surface of the earth, the hyphae grow together more tightly, forming a fruiting body, which we are accustomed to calling a mushroom.
Principles of mushroom classification
There are various classifications of fungi, differing in the principles underlying them (Fig. 5). Depending on the growing conditions, a distinction is made between wild and cultivated tribes (champignons, oyster mushrooms, winter mushrooms, etc.).
According to their medical and biological properties (the content of toxic substances), the tribes are divided into edible (ceps, milk mushrooms, honey mushrooms, etc.), conditionally edible (Valui, Gladysh, Serushki, etc.), inedible (Bile Tribe, Pepper Tribe, etc.) and poisonous ( death cap, thin pig, etc.). According to the time of formation of fruiting bodies and collection, mushrooms are distinguished: spring (morels, strings); summer-autumn (white boletus, boletus, boletus, milk mushroom, chanterelle, russula, etc.); autumn (honey mushrooms, greenfinches, Polish trib, etc.).
Based on the structure of the fruiting bodies and the location of the hymenophore on them, the tribes can be divided into two groups: basidial - tubular (white, boletus, etc.), lamellar (milk mushrooms, honey mushrooms, fly agarics, etc.); marsupials - with smooth, wrinkled, cellular, furrowed hymenophore (stitches, morels, etc.).
Based on the color change during drying, white ( White mushroom) and black (all other types allowed for drying). The above classifications divide mushrooms into groups according to one or more convenient but arbitrary characteristics for humans. Moreover, within groups, the similarity between individual species in a number of other characteristics may be minimal. For example, the troupe of conditionally edible mushrooms includes tubular and lamellar mushrooms that form fruiting bodies both in spring and autumn.
A clearer classification of fungi exists in mycology. It is based on the structural and developmental features of fungi. According to this classification, mushrooms are divided into divisions, classes, orders, families, genera and species. Edible mushrooms in this case are representatives of the true mushrooms department and its two classes: ascomycetes and basidiomycetes (see Fig. 5).
Edible mushrooms belonging to the class of ascomycetes are characterized by different shapes caps (conical, ovoid-rounded, indefinite); the surface of the cap can be cellular, wrinkled, tortuously folded. The leg is central, cylindrical, hollow, pitted or longitudinally grooved. Spores are formed in bags on the surface or inside the fruiting body. Most of these mushrooms belong to the order Peciaceae, the families of Helwellaceae and Morchella mushrooms (conical morel, common morel, common morel). (See Appendices. Key table.)
Most of the fungal species analyzed in the manual belong to the class of basidiomyces to the group of orders Hymenomycetes (see section 1.1.2). According to the structure of the fruiting bodies and hymenophore, as well as other characteristics, hymenomycetes are divided into orders: aphyllophoral, polyporal, boletal, atarical, russular (russula) and a group of orders gasteromycetal, among which the most famous are tribes of the order puffball.
The most numerous representatives of the orders are boletal, agaric, and russular. The structure of the fruiting bodies of these fungi was discussed above, and their representatives number tens and hundreds of species. This can be seen even by the name of the families: boletaceae (white, boletus, moss mushrooms, etc.), pigweed (thin and thick pigworts, etc.), mokrukhovaya, row (meadow honey fungus, winter mushroom, row, govorushka, etc.), Russula (Valui, white and black milk caps, milk mushrooms, wolves, russula, saffron milk caps, etc.), arachnoid (annular cap, fibers, hebelems, cobwebs), pleurotaceae (common oyster mushroom), strophariaceae (summer honey fungus, scaly mushroom).
Gasteromycetal mushrooms have spherical, pear-shaped, tuber-like fruiting bodies, inside of which there is a hymenophore. The tissue of mushrooms is dry and fleshy. When the spores mature, the fruiting bodies open or rupture and the spores disperse into environment. Of the edible mushrooms of this order, puffballs are known. In the practice of harvesting mushrooms, it is customary to divide them into categories. The list of mushrooms belonging to one category or another has been determined Sanitary rules on the procurement, processing and sale of mushrooms, reprinted and approved several times. This division, according to publications, is based on the consumer properties of mushrooms, and above all - their nutritional value and physical parameters (size, consistency, taste, smell of fruiting bodies). However, the Rules themselves do not justify the division of mushrooms into categories, although in their latest edition (SP 2.3.4.009-93) the categories of many mushrooms have been changed in accordance with new data on their nutritional value.
The List contains 58 species of mushrooms permitted for harvesting, of which 57 species actually grow in Russia. The first category includes only 3 species: white trib, true milk mushroom and true camelina (see Table 24, Section 1.8).
The second category is boletus (grainy and late), common boletus, aspen boletus (yellow and red-brown), champignons (common and field), white mushroom and milk mushroom (aspen and yellow), Polish mushroom. The third category, according to the Rules, includes 26 species of mushrooms, including moss mushrooms, chanterelles, honey mushrooms, valui, volushki, russula, black milk mushrooms, and morels. The fourth category covers mushrooms that have a pronounced bitter taste and a coarser pulp consistency: pepper milk mushrooms, bitter mushrooms, black mushroom mushrooms, ryadovka, serushka and some others.
If we approach this division critically, it is clear that, on the one hand, a large number of mushrooms that are valuable in nutritional terms and safe for human health are not included in the list at all. Indeed, according to information available in the literature, more than 200 species of mushrooms are edible. Thus, 3/4 of edible mushrooms, due to ignorance, are considered “toadstools” or - in best case scenario- classified as little-known edible mushrooms. This list includes the common mushroom, called “matsutake” in Japan and recognized there as one of the most delicious mushrooms; annular cap, classified in Europe and Scandinavian countries as the highest category of mushrooms; white dung beetle and some others.
In addition, the value of a number of mushrooms in the Rules is clearly underestimated. For example, morels have higher nutritional properties than are presented in this classification. In many countries they are equated with porcini mushrooms and champignons, which are considered delicacies. It is not advisable to evaluate all types of russula equally. In Finland, for example, they are divided into three groups, as described by M. Korhonen: delicious (edible russula, bluish-green, yellow, brownish), good (swamp russula, graying, purple-red) and inedible (acrid russula, related) . Perhaps such a division is not entirely acceptable for our country, since the sorting of russula when harvesting individual species It is very problematic, but it is also undesirable to equate them in terms of consumer properties with morels and autumn honey mushrooms.
In addition to the above classifications, mushrooms are systematized according to other principles. Thus, according to ecological characteristics (growth and nutritional conditions), tribes are divided into xylotrophs (wood-destroying fungi), mycorrhiza-formers and staprotrophs.
Xylotrophs play a dual role in the forest. They destroy (mineralize) dead wood (stumps, branches) and forest litter, thereby accelerating the cycle of mineral compounds in the soil. On the other hand, they can affect the trunks, branches and roots of living trees, reducing the potential productivity of the forest by 10-30%, and spoil forest products during storage. Of the edible mushrooms, this group includes autumn honey fungus, winter trib, oyster mushroom and some others.
Mycorrhiza-formers are fungi that develop on the roots of trees with benefits for both organisms. Forming the so-called mycorrhiza (fungal root), mushrooms absorb organic substances produced by the roots of the tree, and in return partially take over the function of its sucking root hairs. At the same time, the tree, due to the large surface of the hyphae, is better provided with moisture and minerals from the soil. This is a classic example of symbiosis - mutually beneficial cohabitation. At the same time, certain types of mushrooms gravitate towards certain tree species: boletus - to birch, boletus - to aspen and birch, and boletus, chanterelles, greenfinch, porcini mushrooms and some others - to pine. White mushrooms can also grow with trees of other species; hence the variety of forms of porcini mushroom described by B.P. Vasilkov: spruce, oak, birch, pine (pine). Icorrhiza-formers include most types of edible mushrooms. Saprotrophs are fungi that decompose dead plant debris. Along with mycorrhiza-formers and other soil fungi, they participate in the cycle of substances, contribute to increasing soil fertility and plant development. Champignons, talkers, rotatics and many others have similar properties.
At the same time, in their natural habitat, tribes are in certain contact with vertebrates. Squirrels, deer, hedgehogs, and turtles feed on mushrooms, thus contributing to their spread in space. Tribes of the dung beetle family become even more dependent on animals, since it is animals that provide them with the substrate for development. This troupe of fungi is called caprotrophaia (from the Greek “kapros” - dung), and its representatives are white and gray dung beetles.
The above classifications once again emphasize the uniqueness of mushrooms as living organisms, and hence their characteristics as food products and raw materials for various types of processing.
Types of mushrooms
Edible mushrooms
Attitudes to the nutritional value of mushrooms have been different for a long time. Some experts exaggerated their importance, considering mushrooms to be equivalent to meat and eggs. Others, on the contrary, viewed mushrooms as a useless product, which, due to large quantity chitin is almost not digested in the human intestine. But modern data on the chemical composition of mushrooms show that they contain all the substances necessary for the human body (proteins, fats, carbohydrates, mineral salts, vitamins), however, they have a low calorie content, but even when eaten in small quantities they cause a feeling of satiety. This is very important for various fasting diets.
Fresh mushrooms contain approximately 90% water in their fruiting bodies. There are 1 - 3% carbohydrates in mushrooms, which is much less than, for example, in vegetables. Characterized by a complete absence of starch and the presence of glycogen. Fat in mushrooms contains 0.3 - 0.8%, which is slightly more than in vegetables and much less than in meat. Fats contain many free fatty acids, including palmitic, oleic, butyric and acetic acids. Various organic acids also accumulate in edible mushrooms: oxalic, fumaric, malic, citric, tartaric, etc.
Protein in raw fresh mushrooms contains 4 - 5% (in vegetables 1.5 - 2%, in meat 15 - 22%), it is of high quality and is digestible by 70 - 80%. It contains a number of essential amino acids. The protein substances of mushrooms belong to phosphorus-containing glucoproteins and constitute on average 70% of the total amount of nitrogenous substances. The remaining 30% comes from intermediate products of protein metabolism (free amino acids, organic bases, fungin, urea). It is free amino acids in combination with extractive and aromatic substances that stimulate the secretory activity of the gastric glands. Tryptophan, arginine, tyrosine, leucine, etc. are found in free form. Fungin forms the basis of mushroom fiber. Its chemical composition is identical to insect chitin and is not digested in the human intestine, which makes it difficult to digest mushrooms in general. Chitin is found in greater amounts in the stems of mushrooms and in smaller amounts in the caps. Hence the greater nutritional value of the caps compared to the legs. By content minerals mushrooms are not inferior not only to vegetables, but also to many fruits. They contain almost as much phosphorus and calcium as fish. Mushrooms contain potassium, sodium, zinc, manganese, iron, copper, iodine and other elements necessary for humans.
Mushrooms also contain vitamins: A, B1, B2, C, D, PP. There is a lot of vitamin A in chanterelles, saffron milk caps and other mushrooms, colored yellow-orange (the presence of carotene). Some mushrooms have the same amount of vitamin B2 as grain crops, and there is especially a lot of it in summer honey mushrooms. Many types of mushrooms have more vitamin B2 than vegetables and grains. In terms of vitamin PP content, mushrooms are close to the liver. Mushrooms contain a small amount of vitamin C.
The given characteristics of the chemical composition of mushrooms allow us to judge them as valuable food product, although in general the digestibility of mushrooms is low due to the presence of chitin. But at the same time, chitin has a beneficial effect on peristalsis and the entire digestion process. Extractive and aromatic substances of mushrooms stimulate the secretory activity of the gastric glands. In this regard, mushroom broth is not inferior to meat broth. With the addition of mushrooms, dishes made from meat, potatoes, and vegetables become tastier.
Thus, the main value of mushrooms lies not so much in their direct nutritional value, but in the fact that they improve the taste of other products and, by promoting the secretion of gastric juice, increase their digestibility. For better absorption of the mushrooms themselves, it is recommended to grind them, or even better, to prepare a powder from them.
Depending on their taste and nutritional value, edible mushrooms are divided into 4 categories. The first includes porcini mushroom, saffron milk cap and milk mushroom. For the second - boletus, boletus, boletus, champignons, volushki, aspen and yellow milk mushrooms, white milk mushrooms. The third includes moss mushrooms, black milk mushrooms, valui, chanterelles, morels, autumn honey fungus, types of strong russula. To the fourth - meadow honey fungus, summer honey fungus, umbrella mushrooms, brittle types of russula, bitter mushroom, dung beetles, oyster mushrooms, talkers, rows, tinder fungi, cattails and others little-known mushrooms. But this division into categories is rather arbitrary. In different regions and countries, depending on traditions and customs, the division into more and less valuable mushrooms is different. For example, in our country the real milk mushroom is a first-class mushroom, in some countries Western Europe considered inedible. The variegated umbrella mushroom, dung beetles, and oyster mushrooms belong to the fourth category; moreover, in many areas the population does not collect them at all, calling them toadstools, and in some European countries they are considered first-class.
Some types of mushrooms can be eaten only after special processing (drying, boiling or soaking). They are called conditionally edible. Their fruiting bodies contain poisonous or very bitter substances, which are destroyed when dried or boiled. These include morels, volushki, milk mushrooms, valui and bitter types of russula.
Morels and russula are boiled for only 3 - 5 minutes, the broth is poured out, and the mushrooms are fried, stewed or used in soup. Volnushki, milk mushrooms, valui are boiled for 20 - 30 minutes or soaked in salted water for 1.5 - 2 days and then salted.
There is also a group of mushrooms, the consumption of which can also lead to poisoning. For example, gray dung beetle - delicious mushroom, but in the presence of alcohol in the body it gives a strong allergic reaction. Therefore, after drinking alcohol, you should not drink it for 24 hours.
Names of edible mushrooms.
1. Porcini mushrooms
2. Chanterelles
4. Boletus mushrooms
5. Boletus
7. Russula
8. Champignons
Poisonous mushrooms
Mushrooms are considered poisonous if their fruiting bodies contain toxic substances - toxins that cause poisoning. There are several dozen species in total poisonous mushrooms. Most of them cause not very severe and short-lived illnesses, mainly associated with digestive disorders. But there are several species that cause severe poisoning, even death. It should be noted that the consequences of poisoning with poisonous mushrooms depend not only on the type of mushroom, but also on the number of mushrooms eaten, on the person’s age and state of health. Poisoning is more difficult for people with poor health and especially children. Children under 5 years old should not be given mushrooms at all.
Depending on the chemical composition and nature of the effect of poisonous mushrooms on humans, they are divided into several groups.
1. Fungi that cause mild poisoning associated with gastrointestinal disorders. The first signs of poisoning occur after 0.5 - 2 hours and manifest themselves in nausea, vomiting, diarrhea, stomach cramps, dizziness, and headache. After gastric lavage and taking sedatives, recovery occurs. This group includes many species: yellow-skinned champignon, false honey mushrooms, yellow fly agaric, gray-pink milkweed, uncooked bitter types of russula, honey mushrooms, honey mushroom, etc.
2. Mushrooms containing the alkaloid muscarine, ibotenic acid, mycoatropine, muscimol, acting on nerve centers. These include fly agarics (red, panther), fibers, talkers (wax and whitewashed), and mycena rosea. The first signs of poisoning appear after 0.5 - 2 hours. They are expressed in facial redness, increased sweating and salivation, shortness of breath, blurred vision, increased heart rate, indigestion, hallucinations, bouts of laughter and crying. Treatment is carried out with atropine.
3. Mushrooms containing coprine - a toxin that dissolves only in alcohol and causes poisoning only when mushrooms are consumed with alcohol. These include gray and shimmering dung beetles, club-footed dung beetle, and dung beetle. Signs of poisoning appear only if alcohol is consumed within 1 - 2 days after eating mushrooms. 0.5 hours after drinking alcohol, redness of the face and whole body begins, stomach pain, diarrhea, vomiting, and a feeling of fear appear. After 2 - 4 hours, all these signs disappear.
4. Mushrooms containing poisonous cyclopeptides - phallotoxins. This group includes the most dangerous, deadly poisonous. This is a pale toadstool, poisonous and white fly agarics, some types of small lepiots. The danger lies in the fact that the first signs of poisoning (diarrhea, vomiting, thirst, cramps, excessive urination) appear after 12 to 24 hours, and sometimes after two or even three days. Then, after about 2 to 3 days, apparent relief occurs. However, by this time, irreversible degeneration of the liver and kidneys has already occurred in the body and death occurs. Such poisonings can be relatively successfully treated (with timely initiation of treatment) with penicillin, vitamins C and K, and thioctacid.
You can also get poisoned edible mushrooms. If they have been lying for a long time (more than a day) in a warm place, then it is dangerous to eat them, since the proteins in them quickly decompose (faster than in fish) and harmful substances are formed. It is also dangerous to eat old, overripe or very wormy mushrooms. In old mushrooms, harmful metabolic products, for example, urea, can accumulate, and in worm-eaten mushrooms, waste from the life of insect larvae can accumulate. Mushrooms collected from areas treated with pesticides and herbicides are also dangerous; mushrooms collected near highways with heavy traffic (they accumulate poisonous heavy metals and, above all, lead). You can also be poisoned by uncooked honey mushrooms, honey mushrooms and other mushrooms that are poisonous in their raw form. But still, most often they are poisoned by poisonous species.
Unfortunately, there are no common signs common to all poisonous mushrooms; each species has its own characteristics. Let's consider features main poisonous mushrooms. Of the fly agarics in Udmurtia, the most common are red, panther, porphyry, yellow and pink, less often - stinking or poisonous. All of them, with the exception of the pink fly agaric, are poisonous. The smelly fly agaric is especially dangerous. His fruiting body white and with an unpleasant odor, consuming it even in small quantities can lead to death. This mushroom is comparable in toxicity to the infamous toadstool.
Fortunately, all fly agaric mushrooms have clear distinctive features that make them easy to distinguish from other mushrooms. Please remember these signs. On top of the cap there are dirty white single or numerous flakes; near the middle of the stem or a little higher there is a membranous ring, usually white or slightly yellowish for the yellow fly agaric. The lower end of the stalk is often thickened and on it there are ring-shaped rows of warts or ridges (red and panther fly agarics) - these are the remains of a common blanket, completely fused with the stalk.
In other species, this membranous remnant covers the lower part of the leg in the form of a sock and is called free. The volva of the porphyry and yellow fly agaric is fused with the stalk, but its upper edge remains free, in the form of a cuff.
The leg of the stinking fly agaric and pale toadstool has a completely free volva, in the form of an open pouch.
In all of the listed species of fly agaric, the plates on the underside of the cap are white and do not change this color with age. This feature easily distinguishes them from champignons, whose plates turn pink and then turn black with age.
The combination of features (flakes on the cap, ring and volva on the leg, white plates) always indicate that it belongs to the fly agaric. But we must keep in mind that the spots on the cap and the ring on the stem are not permanent signs - they can be washed away by rain. But unchanging white plates and especially the presence of a Volva are constant signs, and first of all you need to focus on them.
All mushrooms more or less similar in external outline to fly agarics (russula, champignons, rowers, cobwebs) do not have any signs of being free, so when collecting them it is necessary Special attention turn to the base of the leg.
Fiberworts are relatively small mushrooms that are abundantly found in the forests of Udmurtia in June - August. The caps of young fruiting bodies are usually bell-shaped, then open, but a conical tubercle always remains in the center. A characteristic feature of the cap is that the top is longitudinally fibrous or streaked, often with cracks running from the edge. Many types of hair cavalry have a specific odor, similar to the smell of damp crumpled paper or fruit. They are very poisonous, so it is better not to collect any mushrooms with the slightest signs of fibers.
Strings grow in pine and mixed forests in May - early June. The cap is shapeless, with brain-like convolutions of brownish tones. The substance gyromitrin contained in the fruiting bodies is a strong poison, but it is destroyed when dried. Therefore, dry stitches can be used to prepare mushroom dishes. Some mushroom pickers use the lines after boiling. But there are many cases of poisoning with fresh stitches after prolonged boiling. Therefore, it is better not to use fresh lines.
Sulfur-yellow false honey fungus grows, like edible honey fungus, on stumps or dead trees in large groups. It can be easily distinguished from edible honey mushrooms by the unpleasant smell and bitter taste of the pulp (you can chew a piece of the cap and spit it out).
POISONOUS MUSHROOMS:
1 panaeolus;
2 float gray;
3 glowing talker;
4 common veselka;
5 pale grebe;
6 - white fly agaric (spring)
7 - red fly agaric;
8 - variegated champignon;
9 - russula emetic;
10 - value;
Classification of mushrooms. Fungi can be divided into 7 classes: chytridiomycetes, hyphochytridiomycetes, oomycetes, zygomycetes, ascomycetes, basidiomycetes, deuteromycetes.
Eumycetes presented ascomycetes And basidiomycetes(perfect fungi), as well as deuteromycetes (imperfect fungi). Ascomycetes(or marsupial fungi) comprise a group of fungi that have septate mycelium and are distinguished by their ability to reproduce sexually. Ascomycetes received their name from the main fruiting organ - the bursa, or ascus, containing 4 or 8 haploid sexual spores (ascospores). Ascomycetes include representatives of the genera Aspergillus, Penicillium, etc., distinguished by the peculiarities of the formation of fruiting hyphae. In Aspergillus, at the ends of the fruiting hyphae there are thickenings - sterigmata, on which chains of spores - conidia are formed. Some Aspergillus species can cause aspergillosis and aflatoxicosis. Fruiting hypha in fungi of the genus Penicillium(tassel) resembles a brush, since thickenings are formed from it, branching into smaller structures - sterigmata, on which there are chains of conidia. Penicillium can cause diseases (penicillinosis). Many species of ascomycetes are producers of antibiotics.
Representatives of ascomycetes are also yeast - unicellular fungi that have lost the ability to form true mycelium. Basidiomycetes- cap mushrooms with septate mycelium.
Deuteromycetes- imperfect fungi - are a conditional class of fungi that unites fungi with septate mycelium that do not have sexual reproduction. They reproduce only asexually, forming conidia.
To imperfect mushrooms include fungi of the genus Candida, which affect the skin, mucous membranes and internal organs (candidiasis). They have an oval shape, a diameter of 2-5 microns; They divide by budding (blastospores), form pseudomycelium (budding cells from the germ tube are extended into a thread), at the ends of which there are chlamydospores. These fungi are called yeast-like. True yeasts (ascomycetes) form ascospores and do not have pseudomycelium or chlamydospores.
The vast majority of fungi that cause diseases in humans (mycoses) are imperfect fungi.
Precipitation reaction. Mechanism. Components.
Precipitation reaction (RP)- This is the formation and precipitation of a complex of soluble molecular antigen with antibodies in the form of cloudiness, called precipitate. It is formed by mixing antigens and antibodies in equivalent quantities; an excess of one of them reduces the level of immune complex formation. RP is set in test tubes (ring precipitation reaction), in gels, nutrient media, etc. Varieties of RP in semi-liquid agar or agarose gel have become widespread: double immunodiffusion according to Ouchterlony, radial immunodiffusion, immunoelectrophoresis, etc.
Mechanism. It is carried out with transparent colloidal soluble antigens extracted from pathological material, environmental objects or pure bacterial cultures. The reaction uses clear diagnostic precipitating sera with high antibody titers. The titer of the precipitating serum is taken to be the highest dilution of the antigen, which, when interacting with the immune serum, causes the formation of a visible precipitate - turbidity.
Ring precipitation reaction placed in narrow test tubes (diameter 0.5 cm), into which 0.2-0.3 ml of precipitating serum is added. Then, using a Pasteur pipette, 0.1-0.2 ml of antigen solution is slowly layered. The tubes are carefully transferred to a vertical position. The reaction is recorded after 1-2 minutes. In the case of a positive reaction, a precipitate appears in the form of a white ring at the border between the serum and the test antigen. In the control tubes, no precipitate is formed.
Meningococci. Taxonomy. Characteristic.
Meningococcal infection is an acute infectious disease characterized by damage to the mucous membrane of the nasopharynx, the membranes of the brain and septicemia; anthroponosis. Taxonomy: The pathogen Neisseria meningitidis (meningococcus) belongs to the Gracilicutes department, family Neisseriaceae, genus Neisseria. Morphological properties. Small diplococci. A typical arrangement is in the form of a pair of coffee beans, with their concave surfaces facing each other. Motile, do not form spores, gram-negative, have pili, the capsule is not permanent.
Cultural properties. They are aerobes, cultivated on media containing normal serum or defibrinated horse blood, and grow on artificial nutrient media containing a special set of amino acids. The election medium must contain ristomycin. Increased concentrations of CO 2 in the atmosphere stimulate the growth of meningococci.
Antigenic structure: Has several AGs: generic, common for the genus Neisseria (protein and polysaccharide, which are represented by polymers of amino sugars and sialic acids); species(protein); group-specific(glycoprotein complex); type-specific(outer membrane proteins), which distinguish serotypes within serogroups B and C. Capsular antigens are divided into nine serogroups (A, B, C, D, X, Y, Z, W 135 and E). Capsular antigens of some serogroups are immunogenic for humans. Serogroup A strains cause epidemic outbreaks. B, C and Y - sporadic cases of the disease. Based on the differences in type-specific antigens, serotypes are distinguished, which are designated by Arabic numerals (serotypes were identified in serogroups B, C, Y, W 135). The presence of serotype 2 hypertension is considered a pathogenicity factor. During epidemics, meningococci of groups A and C predominate, which are the most pathogenic.
Biochemical activity: low. Decomposes maltose and glk. Before acid, does not form indole and hydrogen sulfide. Fermentation of glk. and maltose - a differential diagnostic sign. Does not form starch-like polysaccharide from sucrose. Possesses cytochrome oxidase and catalase. Absence of β-galactosidase, presence of γ-glutamine transferase.
Pathogenicity factors: capsule – protects against phagocytosis. AT formed in capsule polysaccharides exhibit bactericidal properties. Toxic manifestations of meningococcal infection are caused by highly toxic endotoxin. Generalized forms of meningococcal infection are characterized by skin rashes, pronounced pyrogenic effects, and the formation of AT. Pili, outer membrane proteins, Availability hyaluronidase And neurominidase. Pili are an adhesion factor to the mucous membrane of the nasopharynx and tissues of the meninges. Meningococci secrete IgA proteases that break down IgA molecules, which protects the bacteria from the action of Ig.
Resistance. Low stability in the external environment, sensitive to drying and cooling. It dies within a few minutes when the temperature rises above 50 °C and below 22 °C. Sensitive to penicillins, tetracyclines, erythromycin, resistant to ristomycin and sulfonamides. Sensitive to 1% phenol solution, 0.2% bleach solution, 1% chloramine solution.
Epidemiology, pathogenesis and clinic. Humans are the only natural host of meningococci. The nasopharynx serves as an entry point for infection; here the pathogen can exist for a long time without causing inflammation (carriage). The mechanism of transmission of infection from a patient or carrier is airborne.
The incubation period is 1-10 days (usually 2-3 days). There are localized (nasopharyngitis) and generalized (meningitis, meningoencephalitis) forms of meningococcal infection. From the nasopharynx, bacteria enter the bloodstream (meningococcemia) and cause damage to the meninges and mucous membranes with the development of fever, hemorrhagic rash, and inflammation of the meninges. Immunity. Post-infectious immunity in generalized forms of the disease is persistent and intense.
Microbiological diagnostics: Material for research - blood, cerebrospinal fluid, nasopharyngeal swabs.
Bacterioscopic method– Gram staining of smears from cerebrospinal fluid and blood to determine the leukocyte formula, identify meningococci and their number. Polynuclear leukocytes, erythrocytes, fibrin threads, meningococci - gram “-” are observed, surrounded by a capsule.
Bacteriological method– isolation of pure culture. Nasopharyngeal mucus, blood, cerebrospinal fluid. Sowing on solid, semi-liquid nutrient media containing serum and blood. Cultures are incubated for 20 hours. At 37C with an increased CO 2 content. Oxidase-positive colonies belong to this species. The presence of N. meningitidis is confirmed by the formation of acetic acid during the fermentation of glucocorticoids. and maltose. Belonging to serogroups is determined by the agglutination reaction (RA).
Serological method– used to detect soluble bacterial antigens in the cerebrospinal fluid, or antigens in the blood serum. ELISA and RIA are used to detect hypertension. In patients who have had meningococcus, there are specific antibodies in the serum: bactericidal, aggutinins, hemaggutinins.
Treatment. Antibiotics are used as etiotropic therapy - benzylpenicillin (penicillins, chloramphenicol, rifampicin), sulfonamides.
Prevention. Specific prophylaxis is carried out with a meningococcal chemical polysaccharide vaccine of serogroup A and a divaccine of serogroups A and C according to epidemic indications. Nonspecific prevention comes down to compliance with the sanitary and anti-epidemic regime in preschool, school institutions and places of constant congestion of people.
Ticket No. 4
Microscopy methods
Luminescent (or fluorescent) microscopy. Based on the phenomenon of photoluminescence.
Luminescence- glow of substances that occurs after exposure to any energy sources: light, electron rays, ionizing radiation. Photoluminescence- luminescence of an object under the influence of light. If you illuminate a luminescent object with blue light, it emits rays of red, orange, yellow or green. The result is a color image of the object.
Dark-field microscopy. Dark-field microscopy is based on the phenomenon of light diffraction under strong lateral illumination of tiny particles suspended in a liquid (Tyndall effect). The effect is achieved using a paraboloid or cardioid condenser, which replaces a conventional condenser in a biological microscope.
Phase contrast microscopy. A phase contrast device makes it possible to see transparent objects through a microscope. They acquire high image contrast, which can be positive or negative. Positive phase contrast is a dark image of an object in a bright field of view, negative phase contrast is a light image of an object on a dark background.
For phase-contrast microscopy, a conventional microscope and an additional phase-contrast device, as well as special illuminators, are used.
Electron microscopy. Allows you to observe objects whose dimensions lie beyond the resolution of a light microscope (0.2 microns). An electron microscope is used to study viruses, the fine structure of various microorganisms, macromolecular structures and other submicroscopic objects.
The role of I. I. Mechnikov in the formation of the doctrine of
Mechnikov made a huge contribution to the development of immunology. He substantiated the doctrine of phagocytosis and phagocytes. He proved that phagocytosis is a universal phenomenon, observed in all animals, including protozoa, and manifests itself in relation to all foreign substances (bacteria, organic particles, etc.). The theory of phagocytosis laid the cornerstone of the cellular theory of immunity and the process of immunogenesis as a whole, taking into account cellular and humoral factors. For the development of theories of phagocytosis, I. I. Mechnikov was awarded Nobel Prize. L. Pasteur wrote in his portrait, presented to I.I. Mechnikov: “In memory of the famous Mechnikov, the creator of the phagocytic theory.”
№ 6 Morphology of fungi
Mushrooms belong to the kingdom Fungi (Mycetes, Mycota ). These are multicellular or unicellular non-photosynthetic (chlorophyll-free) eukaryotic microorganisms with a cell wall.
Mushrooms have a nucleus with a nuclear envelope, cytoplasm with organelles, a cytoplasmic membrane and a multilayered, rigid cell wall consisting of several types of polysaccharides, as well as proteins, lipids, etc. Some fungi form a capsule. The cytoplasmic membrane contains glycoproteins, phospholipids and ergosterols. Fungi are gram-positive microbes, vegetative cells are non-acid-resistant.
Mushrooms consist of long thin threads (hyphae) intertwined into mycelium, or mycelium. The hyphae of lower fungi - phycomycetes - do not have partitions. In higher fungi - eumycetes - the hyphae are separated by septa; their mycelium is multicellular.
There are hyphal and yeast forms of fungi.
Hyphal(mold) fungi form branching thin threads (hyphae) intertwined into mycelium, or mycelium (mold). Hyphae growing into the nutrient substrate are called vegetative hyphae (responsible for feeding the fungus), and those growing above the surface of the substrate are called aerial or reproductive hyphae (responsible for asexual reproduction).
Hyphae lower mushrooms do not have partitions. They are represented by multinucleated cells and are called coenocytic.
Hyphae higher mushrooms are separated by partitions, or septa with holes.
YeastFungi (yeasts) mainly have the appearance of individual oval cells (unicellular fungi). According to the type of sexual reproduction, they are distributed among higher fungi - ascomycetes and basidiomycetes. When reproducing asexually, yeast buds or divides, resulting in single-celled growth. They can form pseudohyphae and false mycelium (pseudomycelium) in the form of chains of elongated cells - “sausages”. Fungi that are similar to yeast, but do not have a sexual method of reproduction, are called yeast-like. They reproduce only asexually - by budding or fission.
Mushrooms multiplyspores by sexual and asexual means, as well as by vegetative means (budding or fragmentation of hyphae). Fungi that reproduce sexually and asexually are classified as perfect. Imperfect fungi are those in which sexual reproduction is absent or has not yet been described. Asexual reproduction is carried out in fungi with the help of endogenous spores that mature inside a round structure - sporangium, and exogenous spores - conidia, which form at the tips of fruiting hyphae.
Types of mushrooms.There are 3 types of fungi that have a sexual method of reproduction (the so-called perfect fungi): zygomycetes ( Zygomycota), ascomycetes (Ascomycota ) and basidiomycetes ( Basidiomycota ). Separately, a conditional, formal type/group of fungi is distinguished - deuteromycetes ( Deiteromycota ), which only have asexual way reproduction (so-called imperfect mushrooms).
