The importance of algae in nature message. The role of algae in nature

The biological role of aquatic and terrestrial algae is multifaceted and ambiguous.

Due to their wide distribution, algae are of great importance in the life of individual biogeocenoses, in the cycle of substances in nature, and in the life of the entire planet Earth. They are of great importance in the economic, scientific, and practical activities of man.

Algae, having adapted to life in a wide variety of conditions, represent a very convenient object for studying the mechanism of adaptation, because algae, and especially unicellular ones, combine the morphological characteristics of a cell, but react to changes in the external environment as an independent organism.

Recently, algae have acquired great importance in practical and scientific human activities. In scientific research, algae are used as a convenient model for research in various branches of biology, pharmacy, veterinary medicine and medicine - cytology, biochemistry, physiology, genetics, genetic engineering, molecular biology, etc.

The theoretical significance of algae is associated with research in solving physiological, biochemical, biophysical, environmental and general biological problems.

Algae cultures are used in closed systems when performing scientific research in biophysics, genetics, biochemistry, physiology, biotechnology, etc.

Algae, like all green plants, under the influence of sunlight or artificial sources of ultraviolet rays, use carbon dioxide in the air and release pure oxygen. In order to clean the air from carbon dioxide and replenish oxygen reserves, algae are cultivated in hermetically sealed rooms (on submarines, spaceships).

Algae are also objects of space research.

The widespread distribution of algae in nature and the massive development of algae in different habitats determines their large and steadily increasing role in practical human activities.

Algological knowledge is becoming necessary for specialists in various fields of the national economy.

Algae are an important link in the processes of biological purification of water, soil, and air. Participate in the circulation of substances, including calcium and silicon.

Large algae are used as livestock feed, to produce agar, iodine, and canned food. In some areas, algae is used as fertilizer.

The role played by both aquatic and terrestrial algae in the life of the living and nonliving world around us is multifaceted and ambiguous.

And we are constantly faced with both positive and negative manifestations of the vital activity of algae.

Microscopic algae that live in water are mainly part of the group of organisms that make up plankton.

Plankton represents a group of aquatic plant and animal organisms that lead a free-floating (independent of a solid substrate as a supporting element), suspended in the water column, lifestyle.

Phytoplankton organisms are characterized by either a complete absence of organs of movement or these organs are so poorly developed that these organisms cannot withstand even a weak flow of water and their active movement occurs only within small limits.

The only support for planktonic organisms is the water in which they soar or swim, being adapted by their entire body organization to such a peculiar way of life.

Plankton includes mainly small, often microscopic organisms, and only some representatives of zooplankton can reach sizes of several millimeters.

Algae, together with bacteria and protozoa, are the initial links in the food chains of water bodies. They are an important source of food for numerous species of fish.

Schematically, this can be represented as follows: bacterioplankton – phytoplankton – zooplankton – fish – humans and animals.

Aquatic algae are the creators of organic substances in a body of water, without which the existence of all other aquatic organisms, including zooplankton and fish, is impossible. A variety of small animals, including daphnia and cyclops, feed on algae, and they in turn serve as food for fish.

The nutritional value of plankton, including phytoplankton, in terms of protein and fat content is not inferior to the value of many food plants. The abundance of the smallest plant organisms in water bodies determines the number of their animal populations.

The role of algae is especially great in the formation of organic substances in natural bodies of water, where they influence fish production through several intermediate links.

For artificial fish breeding, reservoirs with rich phytoplankton are chosen.

Algae play a large role in the processes of self-purification of water in open reservoirs.

The role of algae in the biosphere as primary producers of organic matter is very great: their biomass in the World Ocean is more than 1.5 billion tons, and their annual production is more than 25% of all organic matter on the planet.

Algae, being the oldest photosynthetic organisms on Earth, created its oxygen atmosphere. Land plants originated from them.

Distributed throughout the globe, they play a huge role in the life of nature, which is primarily determined by their characteristics as photoautotrophic organisms.

In water, on the one hand, they are the main creators of organic matter and are one of the first links in food chains, and on the other hand, the very important importance of algae is that during the process of photosynthesis they release free oxygen necessary for the respiration of aquatic living plants and animals organisms.

Algae, creating organic substances, absorb carbon dioxide, and in the light, like higher plants, they release oxygen necessary for the respiration of aquatic organisms.

Algae living in the aquatic environment determine the level of biological productivity of the reservoir.

Aquatic algae are good stewards of their environment. Feeding, like bacteria, on organic substances that make up wastewater, they purify it.

Algae such as Chlorella vulgaris, Scenedesmus obliquus, Ankistrodesmus angustus not only grow well on wastewater from pig farms and poultry farms, but also contribute to more intensive purification of organo-mineral contaminants.

Volvox, euglena, yellow-green, pyrophytic, dianoma, green, blue-green algae, together with heterotrophic organisms, are good orderlies, carrying out the processes of natural self-purification of waste and polluted waters.

Algae play a major role in the processes of self-purification of water bodies, consuming nutrients and enriching the water with oxygen.

Algae are very sensitive to the chemical composition of water, and therefore can serve as good indicators of the degree of environmental contamination with various chemical pollutants.

As the main photosynthetic link of the ecosystem, algae play a vital role in the formation of the chemical composition and reserves of organic substances in water bodies.

Recently, the importance of algae in the accumulation of soluble organic compounds in aquatic ecosystems has especially increased.

Algae from continental reservoirs play a large role in the formation of medicinal mud.

Dead plankton settles, contributes to the accumulation of sediments, is part of detritus and is used as nutrients for bacteria, fungi, and actinomycetes, which finally destroy dead organic matter.

Planktonic algae that inhabit reservoirs die and sink to the bottom of the reservoir and, together with other dead organisms of the reservoir, form sediments called sapropels under anaerobic conditions.

Sapropel is rotting sludge, which is a raw material for the production of gasoline, kerosene, resins, oils and other valuable products used for the needs of the national economy. Sapropel coals are used for heating, and sapropel sludge is used to fertilize the soil and feed animals.

Diatoms, green, and golden algae participate in the formation of silts, sapropels, and limestones.

Almost all freshwater algae are used as soil fertilizers.

Among aquatic algae there are nitrogen fixers. In rice fields where representatives of the genus Anabaena develop, rice yield increases without the application of nitrogen fertilizers.

Diatoms are directly related to the formation of the sedimentary rock diatomite, which is used in technology as an insulating material.

Regulation of the regime of reservoirs and canals is completely impossible without taking into account the ecology and physiology of seasonal changes occurring in the quantitative and species composition of algae.

Canals built by man play an important and diverse role in his economic activities. They are a special type of reservoir.

During the operation of canals, serious biological disturbances arise, the culprits of which are various aquatic organisms.

Among them, one of the main places belongs to algae.

Mainly diatoms (Stephanodiscus hantzschii), green (Scenedesmus quadricauda) and blue-green algae Aphanizomenon flos - aque, Microcystis aeruginosa develop in the canals.

The main factors determining the dynamics of the composition and quantity of phytoplankton in canals are the speed of water flow, the operation of pumping stations and other hydraulic structures, the composition of phytoplankton coming from a water source and its adaptability to the conditions of watercourses, water transparency and the presence of nutrients both introduced from water sources and ingested into channels from surrounding areas or from silt deposits, meteorological conditions on the route, the degree of development of phytobenthos and higher aquatic vegetation.

Algae in canals play a large and varied role. It depends on the composition and abundance of phytoplankton and phytobenthos, as well as on the purpose of the channels, since the water of artificial streams is used by humans for different purposes and is subject to different requirements.

In water channels, algae play a large role in determining water quality.

In irrigation waters, microscopic algae (especially planktonic ones) usually play a positive role, since organisms carried with water to fields serve as good fertilizer and participate in increasing soil fertility.

The importance of algae in the national economy is varied.

Algae are used in agriculture, medicine, and industry.

Marine macrophytes (Porphyra, Rhodimenia, Laminaria, Alaria, Undaria, etc.) are used for cooking, seasonings, soups, confectionery (Spirulina platensis), and animal feed.

Not only seaweeds are used as a cheap food product, but also some freshwater blue-greens (including Sphaeronostoc pruniforme, Stratononostoc commune, Nematonostoc flagelliforme, etc.) that are widespread and found at the bottom of ponds and lakes.

In navigation, algae can be used as indicators of ice-free water, and for fishermen - as indicators of the presence of fish.

For municipal services, algae are important not only as participants in water self-purification processes, but also as indicators of water quality.

Many types of algae are indicators of biological and anthropogenic pollution and salinity.

Currently, much attention is paid to biological control of changes occurring in the environment. Indicators of biological monitoring are functional and structural parameters. Algae, as biological indicators (saprobes), occupy one of the leading places.

Saprobes (biological indicators) are a group of microorganisms used to measure the degree of environmental pollution by various organic and other substances. This group is very large and diverse. It includes fungi, bacteria, actinomycetes, algae, protozoa and other organisms that live in soil, water, and air.

Among the representatives of phyto- and zooplankton, inhabitants of the soil and air, more than 800 species have been identified that are especially sensitive to various organic substances in suspended or soluble states. Some of these organisms need these substances (as in food), while others, on the contrary, find it difficult or completely unable to tolerate the presence of these substances. Some of them, in order to preserve the species in unfavorable conditions, transform from a vegetative form into spores or cysts and in this state can remain in water and soil for decades without losing their viability. There are also those that cannot withstand changes in environmental pH, chemical composition, humidity, temperature, quantity and quality of nutrients, daylight hours, radiation exposure, depth of the water or soil layer, height of the air layer, etc.

This dependence is especially acute in aquatic organisms - any changes in the environment affect the rate of their reproduction and development.

This served as the rationale for the use of algae as biological indicators that make it possible to judge the degree and nature of water, soil, and air pollution.

Algae are involved in the processes of creating medicinal mud; they are producers of vitamins and antibiotics (Scenedesmus obliguus), used in medicine, and biologically active substances.

In medical practice, algae are used to obtain iodine, bromine, and drugs used for preventive and therapeutic purposes in sclerosis, thyroid dysfunction, and in the treatment of long-term non-healing wounds (Laminaria digitata, L.clustoni).

There are edible algae that are sources of proteins, fats, and carbohydrates.

Algae, and especially Chlorella pyrenoidosa, Scenedesmus quadricauda, ​​are used as objects in physiological and biochemical studies.

Algae living in soils increase their fertility and participate in the formation of humus, as a result of which freshly watered substrates become suitable for the life of other plants.

Terrestrial algae play the role of pioneers of vegetation on barren, rocky areas of land, as accumulators of primary humus, preparing the possibility of settlement of other plants.

Soil algae are important for livestock farming; they are used to feed animals.

To increase productivity, algae is used to fertilize the soil.

Algae play a large role in enriching soils with nitrogen at the expense of atmospheric nitrogen.

About 30 species of blue-green algae are active fixers of free nitrogen from the air. Among them are such species as: Cylindrosperum musciola, Tolypothrix tenuis, Anabaena cylindrical, Anabaena oryzae, Anabaena variabilis, Nostoc prunifirme, Nostoc paludosum, Nostoc muscorum, Nostoc coeruleum, Nostoc lincria, Nostoc microsporicum, Nostoc punctiforme, Nostoc flagelliforme.

Among soil algae, as well as among aquatic algae, there are active producers of vitamins and other biologically active substances. Green algae Chlorella vulgaris and Scenedesmus obliguus produce antibiotics that inhibit some pathogenic bacteria.

Soil bacteria are bioindicators of industrial pollution and soil toxicity after the application of herbicides or other poisons.

Accounting for the total amount of algae or differentiated accounting for groups of algae in one gram of soil can be used to assess the toxic effect of pesticides on soil microflora.

The first hypotheses about the importance of algae in soil life appeared more than 100 years ago. Since then, the ubiquity of soil algae and their role in the colonization of various lifeless substrates and the creation of independent groups or algocenoses in combination with other organisms have been repeatedly proven.

On the surface of the soil and in its upper layers, algae create organic matter through the process of photosynthesis and are products of biogeocenosis.

Soil algae are the only group of producers of terrestrial ecosystems, whose production in most cases exceeds biomass many times. This is especially evident when Nostoc commune predominates.

Soil algae are centers of intensive development of heterotrophic microorganisms.

The main form of interaction between soil algae and bacteria living in the soil is association. There are numerous examples of the coexistence of algae with fungi.

Algae, as active components of soil microflora, participate in the general life of the biogeocenosis and play an important role in the biological cycle of ash elements.

Formed under the influence of the main components of biogeocenosis - plant cover and soil, algae reflect their characteristics and can be indicators of their genesis and condition.

Algae, like other living organisms, have a negative impact on the environment.

Thus, the negative value of algae is associated with water blooms in reservoirs and canals, clogging of power plant units, water supply filters, and fish kills. Toxic algae occurs.

Algae can clog water supplies and bodies of water as they become eutrophicated. Algae can cause red tides and cause poisoning and illness in people and animals.

Planktonic algae that often cause water blooms include Microcystisssss aeruginosa, Woronichinia noegeliana, Aphanisomenon flos - aquae, Anabaena Lemmermanii, Anabaena Scheremetievi, Rivularia echinulata.

In most cases, blue-green algae cause blooms in fresh water bodies and less often in sea water.

In lakes, ponds and rivers with slow-moving water, blooms are most often caused by species of the genera Anabaena, Microcystis, Gleotrichia.

The cells of the planktonic species Gloertichia gechinulata contain gas vacuoles. During mass reproduction, cells cover the entire water surface, as a result of which air exchange in the reservoir is disrupted, and this in turn causes fish to die.

Excessive accumulation of algae in a reservoir negatively affects the quality of water, its taste and smell, can cause mass poisoning of livestock coming to water, and contributes to siltation of the reservoir and its shallowing.

Algae secrete algotoxins (causing toxicosis and even death) and other active metablites with allergic, mutanogenic and carcinogenic effects. Some types of algae also secrete substances that exhibit antihormonal, bactericidal, insecticidal, and fungicidal activity.

The accumulation of toxic substances in a reservoir, produced by living cells or released during their death and destruction, has a detrimental effect on living organisms.

Most often, the appearance of toxic substances during flowering of a reservoir is associated with the mass reproduction of blue-green algae species of the genera Aphanizomrnon, Microcystis, Nostoc, Anabaena, Nodularia, Gloeotrichia and the species of golden algae Primnesium parvum.

The appearance of toxic sea waters has been known since ancient times. Currently, species of seaweed have also been identified that release toxic and pigmented substances, the effects of which kill people, seabirds, shellfish, fish and other marine life.

Red algal blooms are caused by Haematococcus pluvialis.

Toxic substances are produced by the species Gonyaulax catenella, Gonyaulax monilata, Gymnodinium breve, Gymnodinium veneficium, Nodularia spumigena, Gloeotrichia echinulata, Oscillatoria vauch, Nostoc rivulare.

Species of the genus Gimnodinium cause yellow, rusty-red, dull pink sea blooms during the day, and silvery-white blooms at night.

Species of the genera Nactiluca, Cyricistis, and Ceratium also release toxic substances and cause sea blooms.

The toxic effect of blue-green algae is associated with the phenols that they produce and release into the environment. In humans, these toxic substances cause damage to the gastrointestinal, respiratory, muscular, and skin-mucosal systems. In addition, people develop allergic reactions, conjunctivitis, itching of the nose and eyes, swelling of the eyelids, asthma, and dermatitis.

The poisonous effect of these toxins on humans can occur indirectly through poisoned fish or birds that have eaten poisoned fish.

The toxic effect of toxic metabolites of blue-green algae when consuming poisoned water by animals (cattle and small cattle, sheep, horses, dogs, etc.) and birds (gulls, ducks, etc.) manifests itself in the occurrence of severe weakness, nausea and vomiting, severe thirst, diarrhea mixed with blood, peeling of the mucous membrane, cavitary hemorrhages, ascites.

Damage to the nervous system in horses, cats, dogs, wild animals, and coastal birds manifests itself in the form of convulsions, unsteady gait, twitching and blinking of the eyes, stretching of the neck, decreased body temperature, numbness, lethargy, blockage of the cerebral and spinal blood vessels and meninges. Damage to the liver and spleen, swelling and expansion of the heart, and damage to the pericardium develop.

Polysaccharides extracted intravitally by algae, hydrolyzed by bacteria into mono- and olgosaccharides, deteriorate the quality of natural waters and give them an unpleasant odor and taste, thereby causing the biological unsuitability of waters.

Of particular importance for water supply are certain types of algae that produce aromatic substances that provide a difficult-to-eliminate odor and taste - fishy, ​​grassy, ​​musty, rotten, geranium, earthy, putrefactive, etc.

Aromatic algae are found among diatoms, green, blue-green, golden, and pyrophytes.

When Asterionella develops, earthy, geranium, and fishy odors appear in the water. Species of the genus Synura contribute to the appearance of cucumber and fish odors, representatives of the genus Melosira provide the smell of stale fish oil, and with the massive development of the species Anabaena and Aphanizomenon, grassy, ​​nasturtium, putrid and moldy odors appear in the water.

The production of aromatic substances by algae is influenced by the concentration of nitrogen-containing substances, the physiological state of the algae, the presence of factors that change metabolic processes, and the amount of industrial and waste water discharged into the reservoir.

Amino acids produced by algae such as Anabaena cylindrical, Chlorella vulgaris, Navicula pelliculosa inhibit the metabolic processes of algae and other organisms.

With the massive proliferation of fouling algae, difficulties arise in the water supply and operation of water transport and hydraulic structures.

The fouling of water transport by algae below the waterline causes a slowdown in the speed of movement of these vessels. The massive proliferation of diatoms in the sea water causes clouding of the periscope lenses of submarines.

The massive development of planktonic and benthic algae causes mechanical interference in hydraulic structures, reduces the capacity of canals, reservoirs and other navigable bodies of water, significantly deteriorates the quality of water in terms of hydrochemical and biological parameters, leads to disruption of the operation of water treatment facilities and contributes to the difficulty of water purification at these facilities

The massive development of microscopic algae contributes to an increase in the consumption of reagents used to purify water and remove difficult-to-eliminate odors.

Microscopic algae of the genera Cladophora, Enteromorpha, Spirogira, Oedogonium, Chara cause serious interference in the operation of reservoirs of almost all types.

The massive development of algae contributes to the overgrowing of water bodies and fouling of water pipes.

Algae are a very large and heterogeneous group of lower plants. In addition, they are the most numerous photosynthetic organisms on the planet, which are very important for our nature. You can find algae everywhere. These organisms live in oceans, freshwater bodies and seas, as well as on tree bark and moist soil.

Classification

To date, science has systematized more than one hundred thousand different types of algae. They, in turn, are divided into ten groups depending on the nature of the color:

Blue-green;

Golden;

Pyrophyta;

Yellow-green;

Diatoms;

Red;

Green;

Euglenaceae;

Harovs.

Importance in biogeocenoses

Algae in the aquatic environment are the main producers of organic substances. They not only directly but also indirectly serve as the main source of nutrition for all. Some rocks (oil shale, diatomite and limestone) are known to have appeared in past geological stages as a result of the life cycle of these photosynthetic organisms.

Role in nature

Marine plants are essential for life on our planet. First of all, the importance of algae in nature is due to the fact that they are food for many organisms. These plants feed on crustaceans and mollusks, fish, etc.

Algae are of great importance in nature and as a source of oxygen production. They account for thirty to fifty percent of this valuable substance, which is released by the plant world of our planet.

Just like terrestrial flora, they relieve the atmosphere of the problem of excess carbon dioxide. Sometimes there are so many of them that the water takes on a variety of colors.

Algae perfectly adapt to a wide variety of conditions. These plants can live in rainwater, where the amount of salts is minimal. Their habitat includes rocky hot surfaces and reservoirs of high-mountain glaciers. Algae can also be found in the upper soil layers, where sunlight has difficulty penetrating. These plants are capable of colonizing lifeless rocky and soil substrates. The importance of algae in the nature of such zones is extremely high. These unique plants create the conditions for the soil to be fertile.

The importance of algae in nature is also great for the circulation of substances. First of all, they feed on crustaceans, which are later eaten by fish.

Red algae

Almost all representatives of these plants live in the seas. Red algae have a significant length, which can reach two meters. In addition to chlorophyll, representatives of these species of marine plants contain various pigments in their cells. Their color affects the color of the algae themselves. As a rule, the pigments of such algae are red. However, pink, bluish and other colors are possible.

Which are also called purple ones, have a fragile and delicate body. The color of these plants, from bright red to almost black, gives the underwater kingdom incomparable beauty.

Practical use

The importance of red algae for humans is very great. One of the varieties of these plants, Chondrus, which lives in the North Sea, is used as a medicine to treat respiratory diseases. Agar-agar, used in confectionery, is extracted from red algae. Scarlet flowers are also necessary for microbiologists. In laboratory conditions they are used to obtain microbes.

Brown algae

This species is one of the most important sources of organic matter in coastal zones. This is especially true for the seas of the polar and temperate zones. In these areas, the algae biomass per square meter can reach several tens of kilograms.

Brown algae form real thickets. The significance of these “sea forests” is very great. They provide not only shelter, but also feeding and breeding grounds for many coastal animals. In addition, brown algae create excellent conditions for other micro- and macroscopic algae to reproduce in the area of ​​their distribution.

Amazing plants are the only source in the world for the production of alginic acid salts - alginates. This substance is capable of absorbing up to three hundred weight units of liquid, resulting in a viscous solution. This ability allows brown algae to be used in the food industry. Alginates obtained from them are added to ice cream, canned food and fruit juices. In addition, this substance improves the quality of books when printing, and also serves to impart color fastness to dyed fabrics.

Alginates, produced from brown algae, are needed in the production of synthetic fibers and plastics. They make building materials and paints resistant to weathering. Alginates are also used as raw materials in the production of high-quality lubricants for machines, soluble surgical sutures, pastes and ointments in the perfume and pharmaceutical industries. Brown algae have been used as food for a long time. They are especially revered in the cooking of the peoples of Asian countries.

Green algae

This type of aquatic plant is widespread throughout our planet. Most green algae are found in fresh water bodies, but there are also a considerable number of their marine forms. There are species of these plants that have adapted to terrestrial habitat and to life in soil layers. You can also find green algae on rocks, on the bark of trees, as well as on various buildings. Extensive development zones of these plants contribute to the “blooming” of water, snow, soil, and tree bark.

The importance of green algae in nature is great. First of all, it is a source of oxygen. The role of these plants in cleaning water bodies is also important. The importance of green algae is difficult to overestimate. They process carbon dioxide and those dissolved in water, and also take part in the process of synthesis of organic substances.

Currently, various nutritious products are obtained from these representatives of aquatic flora. They are also used for medical purposes. A special substance is isolated from green algae - chlorellin, which suppresses the spread of a number of pathogenic bacteria in the body. Traditional medicine did not ignore these plants either. Green types are used in pain-relieving compresses.

Due to their abundance and wide distribution, algae are of great importance in individual ecosystems and in the biosphere cycle of substances. The biogeochemical role of algae is primarily related to the cycle of calcium and silicon. Making up the bulk of the “vegetation” of the aquatic environment and participating in photosynthesis, they serve as one of the main sources of organic matter in water bodies. In the World Ocean, algae annually create about 550 billion tons of biomass (about ⅟4 of all organic substances on the planet). Their productivity is estimated here at 1.3-2.0 tons of dry matter per 1 hectare of water surface per year. Their role is enormous in feeding water inhabitants, especially fish, as well as in enriching the hydrosphere and atmosphere of the Earth with oxygen.

Some algae, together with heterotrophic organisms, carry out the processes of natural self-purification of waste and polluted waters. Many of them are indicators of pollution and salinization of habitats. Soil algae actively participate in soil formation.

Algae can be used directly as food products or as raw materials for the production of various substances valuable to humans. Some brown algae are used as fertilizers and for feeding domestic animals. Algae are nutritious, rich in vitamins, iodine and bromine salts. Seaweed (kelp) is recommended for sclerosis and thyroid dysfunction, as a mild laxative.

Seaweed is a raw material for several industries. The most important products obtained from them are agar-agar and algin. Agar is widely used in food, paper, pharmaceutical, textile and other industries. Agar is indispensable in microbiological studies when cultivating microorganisms. In Russia, agar is obtained from ahnfeltia, mined in the White and Far Eastern seas. Algin and alginates, extracted from brown algae, have excellent adhesive properties. They are added to food products, to tablets in the manufacture of medicines, and used in the tanning of leather, in the production of paper and fabrics. Alginates are also used to make soluble threads used in surgery. The possibilities for the practical use of algae are far from being exhausted.

36. The importance of mushrooms in nature and human life.

People have long and widely used mushrooms as a food product. Mushrooms are rich in proteins, in addition, they contain fats, minerals, microelements - iron, calcium, zinc, iodine, potassium, phosphorus. At the same time, the caps contain more phosphorus than the stems.

There are about 300 species of edible mushrooms in our country. However, the number of species consumed as food is usually small. Most edible mushrooms are little known, for example, the umbrella mushroom, some types of row mushrooms, etc. The best edible mushrooms are porcini mushroom, boletus, boletus, boletus, milk mushrooms, saffron milk caps, and autumn honey fungus. Among the mushrooms there are also poisonous ones, but there are relatively few of them. First of all, we should mention the pale toadstool and the stinking fly agaric - deadly poisonous mushrooms for which there is no reliable antidote. Red fly agaric, panther fly agaric, porphyry fly agaric, toadstool fly agaric, some types of fibres, etc. are poisonous to varying degrees. Some poisonous mushrooms are difficult to distinguish from edible ones, so you should never eat unfamiliar types of mushrooms.

Many fungi, especially microscopic ones, form physiologically active substances. These include antibiotics, vitamins (including those from the folic group), organic acids (citric, etc.), a number of enzyme preparations, hallucinogens, etc. Some substances of this kind are produced on an industrial scale for the treatment of humans and animals or for other needs of the national economy (penicillin, citric acid, etc.). Doctors are trying to use psilocybin and psilocin, produced by mushrooms from the genus Psilocybe, to treat mental illness. Preparations from chaga (a sterile form of a type of polypore) increase resistance to cancer and are used to treat peptic ulcers, gastritis and other gastrointestinal diseases. Extracts from the fruiting bodies of some marasmius species suppress the growth of tuberculosis bacillus. The enzyme russulin, produced by one of the types of russula, is used in the production of cheese.

However, mushrooms are important not only as food products or producers of medicinal substances. They play a big role in the cycle of substances in nature. Possessing a rich enzyme apparatus, fungi actively decompose the remains of animals and plants that enter the soil, contributing to the formation of a fertile soil layer. Both soil macromycetes and many microscopic fungi participate in these processes.

Mycorrhiza-forming fungi are of great importance in the life of tree species.

In recent years, a new branch of mycology (the science of fungi) has developed - the study of biodamage to industrial products and materials by microorganisms, especially fungi. Under the influence of fungi, paper and products made from it are destroyed, petroleum oils and fuels, varnishes, paints become unusable, optical products, works of art and much more are damaged.

A special branch of the science of mushrooms is the study of fungal toxins produced by both micro- and macromycetes. Contamination of food products with certain fungi (for example, Fusaria) leads to their intoxication, and consumption of such products as food leads to poisoning.

The meaning of algae. Algae are increasingly used in various sectors of the economy: as food products, as feed concentrates, for the production of chemical compounds, including biologically active substances and medications.

They can be used as indicators of the state of a reservoir, they are bioindicators, and also the initial link in the trophic chain of a reservoir’s ecosystem.

Algae can be considered the primary food source for all aquatic animals. Thanks to the presence of chlorophyll, they synthesize organic substances from inorganic substances. Algae serve as food for waterfowl. Seaweed meal is used to feed farm animals.

The economic importance of algae lies in their direct use as food products or raw materials for the production of various substances valuable to humans. Of the many species of algae, eighty are currently considered edible. Porphyra is considered a delicacy in many coastal countries. In Japan, there are more than 300 types of seaweed dishes. According to statistics, the Japanese eat only 35 times less raw seaweed per year by weight than rice, which, as you know, is considered the “number one dish” in this country.

Brown and red algae are the source of agar-agar, a jelly-like substance used in the confectionery, paper, pharmaceutical industries and microbiology.

Algae are a valuable fertilizer, and marine macrophytes have been used to feed plants for a long time. Algae fertilizers are widely used in Ireland, Scotland, Norway, and France.

Soil algae can largely determine the fertility of a site, and the development of lichens on bare stones is considered the first stage of the soil-forming process.

Algae ash is a raw material for the production of bromine and iodine. Since the discovery of iodine in the mid-19th century, Norway and Scotland have extracted it almost exclusively from benthic plants. During the First World War, when the need for iodine preparations increased sharply, Japanese factories, having processed millions of tons of raw algae, received about 600 tons of iodine. Diatomite is used in abrasive powders and filters, and also serves as a thermal insulation material replacing asbestos.

Negative effects of algae. For humans, algae can be very beneficial and very harmful, cause a number of diseases, because they can create serious problems associated with poisoning water bodies, disrupting the operation of hydraulic structures, fouling on ships, etc. They pollute water sources, often giving them unpleasant taste and smell.

Some algae, especially during periods of their “blooming”, spoil the places reserved for swimming. During storms, many marine macrophytes are torn from the substrate and thrown onto the beach by waves and wind, literally covering it with their rotting mass. In their dense accumulations, fish fry can become entangled. Several types of algae, when ingested by animals, cause poisoning, sometimes fatal. Others turn out to be a disaster in greenhouses or damage plant leaves.

Undoubtedly, health is important for a person. And among the algae there are pathogens that people should know about. Most often these are non-chlorophyll algae, such as algae Prototheca. They cause protothecosis, which manifests itself in skin lesions and subcutaneous infiltrates; sometimes joints are affected. Found in dogs and cattle. The fight against protothecosis is difficult, because the algae is resistant to antibiotics. But it is still detectable (amphotericin B + tetracycline).

Silicosis is possible due to inhalation of diatomaceous earth. In addition to the direct influence of the algae itself, its toxins also act. Once in the body, they cause poisoning and even death. We have already noted the toxicity of blue-green algae, especially the harmful “blooming” of water. “Blooming” of water with the participation of Anabaena flos-aquae, giving serious consequences (toxins can cause liver necrosis, gasteroenteritis, dermatitis). There are also toxic algae among Dinophyta, causing red tides (gymnodinism off the coast of Florida).

to the 90th anniversary of the Department of Hydrobiology of Moscow State University

The world of algae is so diverse that it is impossible to find a place on our planet where these plants are found. Algae live everywhere: in oceans, seas, rivers, lakes, on soil, rocks, trees. Even in snow and hot springs you can find these amazing plants.

We have prepared a series of articles about the ecological features of these algae.

The role of algae in nature is colossal. They are the primary food for many organisms, primarily crustaceans with a filtration type of nutrition. The crustaceans, in turn, are eaten by fish. Algae account for 30 to 50% of the oxygen released by plants (according to various authors). Algae, like land plants, help us solve the problem of excess carbon dioxide in the atmosphere. Sometimes they develop in such large quantities that they color the water in different colors.

Thirdly, algae are very beautiful creatures. For example, diatoms (marine centric diatoms in the micrograph) are a large group of single-celled marine and freshwater algae. Pay attention to the radial symmetry, which is taken as the basis in the taxonomy of this group of algae. They provide food for krill, which in turn feed fish, whales, birds and other sea creatures.

The ability of algae to adapt to a variety of conditions is unique. They live in rainwater with a minimal amount of salts, in salty and super-saline bodies of water, on high-mountain ice and the surface of hot rocks. Algae is found even in the upper layers of the soil, where sunlight barely penetrates. They are the first to colonize the lifeless substrate of rocks and soils, creating conditions for the further development of soil fertility.

Algae, like all plants, synthesize organic substances in the light. And at the same time, many of them are able to live on heterotrophic nutrition, i.e. consume ready-made organic substances.

Due to their wide distribution, algae play an important role in the cycle of substances in nature. Algae of reservoirs are the main food of planktonic, benthic (bottom) organisms, and some types of fish.

Many types of algae (especially red and brown) have been used by humans for food for a long time. Agar-agar, sodium alginate, and some acids used in many industries are obtained from algae. Algae washed ashore have long been used as feed additives for farm animals and poultry, and after rotting - as fertilizer for plants.

Industrial development requires new sources of organic and inorganic substances. Increasing demands contribute to the intensive cultivation of many types of algae in the seas. Man has obtained various strains of microscopic algae rich in proteins, fats, and carbohydrates. Some types of algae are used as food additives for humans and as feed for animals and birds. Algae are used to produce methane from them.

Algae, as the name suggests, are plants that live in water. In botany, the term “algae” is used in a narrower sense, in relation to lower photosynthetic plants that lack division into stems and leaves. This is due to the fact that higher aquatic plants also live in water.

However, a significant part of algae is also found on land: on the surface and subsurface layer of soil, on rocks, tree trunks, buildings and even... in the hair of polar bears living in zoos or the hair of sloths living in the rainforests of South America. However, the life of these plants is in any way connected with water.

These algae easily tolerate drying and freezing and very quickly come to life at the slightest moisture. As soon as a sufficient amount of moisture appears, the surface of the objects becomes covered with a green or red coating (depending on the species composition).

Some algae live as symbionts inside the body of some animals (protozoa, corals, worms, mollusks, etc.). There are types of algae found in ice (on the lower or upper surface) and hot springs. So the term “algae” is more of an ecological concept, meaning a life form of plant organisms united in one group by way of life.

Algae do not have flowers or seeds. The body of the algae is the thallus or thallus (from the Greek “ Thallos" - young branch, shoot) - its structure is much simpler than that of mosses, ferns and other terrestrial plants; there is often no differentiation of cells into tissues. Spores, the reproductive organs of algae, usually lack a hard shell. The cell wall of algae consists of cellulose, pectin, organosilicon compounds (in diatoms), algin and fucin (brown algae). Starch, glycogen, polysaccharides, and lipids are represented as reserve substances.

Based on differences in the structure of the cell (nuclear apparatus, set of pigments, cell membrane, storage substances, etc.), prokaryotic and eukaryotic algae are distinguished. In prokaryotes (from the Latin " about» – before, earlier, instead of and Greek. " karyon" – nucleus) cells do not have a membrane-bound nucleus. These include all bacteria and blue-green algae (or Cyanobacteria - cyanobacteria). In eukaryotes (from the Greek " ew" - good, completely and " karyon" – nucleus) cells contain a formed nucleus. Eukaryotes include all higher animals and plants, as well as unicellular and multicellular algae, fungi and protozoa.

Algae are grouped into departments, the names of which generally coincide with the nature of their color, and in some, with structural features.

Prokaryotic algae (Procaryota):

1. Blue-green algae (Cyanophyta);

2. Prokaryotic (primary) green algae (Prochlorophyta).

Eukaryotic algae (Eukaryota):

1. Euglena algae (Euglenophyta);

2. Dinophyte algae (Dinophyta);

3. Cryptophyte algae (Cryptophyta);

4. Raphidophyta algae;

5. Golden algae (Chrysophyta);

6. Diatoms (Bacillariophyta);

7. Yellow green algae (Xanthophyta);

8. Red algae (Rhodophyta);

9. Brown algae (Phaeophyta);

10. Green algae (Chlorophyta);

11. Charophyta algae.

It should be noted that the taxonomy of algae is not completely settled, so some researchers use a different taxonomy, slightly different from the one given above.

Despite the fact that the history of the study of algae goes back several centuries, there is still no consensus among experts regarding their position in the general classification. This primarily applies to blue-green algae, as well as to all those algae that are equipped with organs of movement - flagella (almost all Euglenophyta, most Dinophyta, certain classes Xanthophyta, Chlorophyta).

Blue-green and prokaryotic green algae are classified as prokaryotes (i.e., non-nuclear organisms), since their cells lack a formed nucleus.

The department of prokaryotic (primary) green algae was separated into a separate group quite recently (1976) after the description of one genus Prochloron and one species P. didemni(Lewin.). This group of algae occupies an intermediate position between prokaryotes - bacteria and blue-green algae, on the one hand, and eukaryotes (nuclear organisms) - green algae. They are similar to bacteria in the absence of a formed nucleus, to blue-green bacteria – the absence of a nucleus and the ability to photosynthesize, and to green bacteria – the presence of chlorophyll “b”. Different researchers solve the question of the systematic certainty of this small group of algae in different ways, depending on the criterion taken as a basis.

Recently, blue-green algae Cyanophyta have begun to be classified as bacterial rather than plant organisms for a number of characteristics (in botanical literature the term “blue-green algae” is most often used, and in microbiological literature – “cyanobacteria”). In Cyanophyta, unlike eukaryotes, there is no formed nucleus, which brings them closer to other prokaryotes; the basis of the cell walls is the glycopeptide murein; the sexual process is either absent or proceeds by the type of conjugation, i.e. fusion of protoplasts of two vegetative cells.

Flagellate forms have characteristics of both plants and animals, which was the reason for uniting them all into a common systematic group of “flagellate organisms” and including them in the system of the animal world. Unlike flagellated animals, algae have chlorophyll and chromatophores (from the Greek " chromium" - color, " foreo" - I carry). However, in the dark they can lose their pigments, become colorless and exist by absorbing organic substances dissolved in water. Some species of unicellular algae (from Dinophyta) are capable, like protozoa, of capturing organic particles.

The science that studies algae is algology(from lat. " alga" - seaweed, " logo" – science) – examines issues of systematics, morphology, physiology, ecology of algae and their practical significance. Algology is one of the branches of botany and is closely related to microbiology and hydrobiology.

When implementing the project, funds from state support were used, allocated as a grant in accordance with the order of the President of the Russian Federation dated March 29, 2013 No. 115-rp) and on the basis of a competition held by the Knowledge Society of Russia.

A.P. Sadchikov,
Professor of Moscow State University named after M.V. Lomonosov,
Vice-President of the Moscow Society
nature testers
(http://www.moip.msu.ru)

.
.
.