Bacteria are saprotrophs. Saprotrophs and their role in biogeocenosis. Saprotrophic bacteria feed

Saprophytic bacteria are one of the most numerous groups of microorganisms. If we talk about the place of saprotrophs in ecological systems, they always displace heterotrophs. Heterotrophs are organisms that cannot produce organic compounds themselves, but are only engaged in processing existing material.

The group of saprotrophs includes representatives of many families and genera of bacteria:

Pseudomonas aeruginosa (Pseudomonas);
Escherichia coli (Proteus, Escherichia);
Morganella;
Klebsiella;
Bacillus;
Clostridia (Clostridium) and many others.

Saprotrophs inhabit all environments in which organic matter is present: multicellular organisms (plants and animals), soils, they are found in dust and in all types of bodies of water (except hot springs).

The result of the action of saprophytic organisms, obvious to humans, is the formation of rot - this is what the process of their feeding looks like. It is the rotting of organic material that is evidence that saprotrophs have taken over.

During the process of decay, nitrogen is released from organic compounds and returned to the soil. The reactions are accompanied by a characteristic hydrogen sulfide or ammonia odor. By this smell one can identify the beginning of the putrefactive decomposition process of a dead organism or its tissues.

Mineralization of organic nitrogen (ammonification) and its transformation into inorganic compounds - such a key role in nature is assigned to saprophytic organisms.

Physiological processes

Saprotrophs, as one of the most numerous groups, have in their ranks representatives with very different physiological needs:

Anaerobes. For example, we can consider E. coli, which carries out its life processes without the participation of oxygen, although it can live in an oxygen environment.
Aerobes are bacteria involved in the decomposition of organic matter in the presence of oxygen. Thus, putrefactive diplococci and three-membered bacteria are present in fresh meat. At the initial stage, the content of ammonia (a waste product of putrefactive microflora) in meat does not exceed 0.14%, and in already rotten meat – 2% or more.
An example of spore-forming bacteria is Clostridia.
Non-spore-forming bacteria are Escherichia coli and Pseudomonas aeruginosa.

Despite the diversity of physiological groups, united according to the characteristics of saprophyte, the final products of the activity of these bacteria have almost the same composition:

cadaveric poisons (biogenic amines with a strong unpleasant cadaveric odor; as such, the toxicity of these compounds is low);
aromatic compounds such as skatole and indole;
hydrogen sulfide, thiols, dimethyl sulfoxide, etc.

But as soon as the required amount of lactic acid ceases to be produced in the intestines, favorable conditions appear for the nutrition, growth and reproduction of putrefactive microflora, which immediately begins to poison a person with the products of their vital activity, which entails severe damage.

Wood rotting

The processing of dead wood and the return of the inorganic compounds of which it consisted to the soil is also carried out with the participation of saprotrophic bacteria. But if they play a key role in the decomposition of animal organic matter, then wood is mainly decomposed by fungi.

Putrefactive processes in wood are not caused by mold fungi. Infection of wood by mold fungi has little effect on the integrity of the wood fibers and the overall appearance of the wood. Damage caused to wood by mold can be easily removed.

The real enemy of wood is the destructive house fungus. This microorganism (eukaryote) turns wood into dust, unsuitable for further use. The presence of real house fungus in the tissues of the tree reduces the quality of the wood several times. Such material is no longer used to produce reliable and beautiful wood products.

Saprotrophs (both bacteria and fungi) feed on those objects that have a certain material value for humans. In fact, they spoil human health, their homes, food, clothing and crops. But nature cannot do without this very important group of the bacterial community. That is why a person needs to look for a way not how to destroy saprotrophs, but how to protect himself from the products of their vital activity.

Converting organic substances of dead organisms into inorganic ones, ensuring the circulation of substances in nature. The term is used to contrast the concept of “parasitic existence of bacteria” (see. parasitism). The term “heterotrophic bacteria” is more often used to indicate the type of bacterial nutrition.

(Source: “Microbiology: a dictionary of terms”, Firsov N.N., M: Drofa, 2006)

See what “saprotrophic bacteria” are in other dictionaries:

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The heterotrophic process occurring in the BGC throughout the entire biogeosphere approximately balances the autotrophic accumulation of matter. During respiration, which is a process of biological oxidation, energy is released. Based on respiration, there are food chains of saprophages.

There are three forms of breathing:

aerobic respiration - oxidizer (acceptor) - oxygen;

Anaerobic respiration has two types:

When an inorganic substance serves as an oxidizing agent

When the acceptor is an organic substance.

Bacteria, yeast, molds and some protozoa carry out their metabolism with the help of anaerobic respiration. Sometimes anaerobic fermentation is a critical component of an ecosystem. For example, thanks to the activity of sulfate-reducing bacteria, there is a stable balance in the Black Sea, which is only 2000 years old. Biologically, this sea is very highly productive - the annual production volume is 1x10 14 g by dry weight, which corresponds to a productivity of about 100 g of carbon per 1 m 2 of surface per year. And since the mixing of waters in the Black Sea is very weak due to the weak intensity of currents, there is only enough oxygen for biological processes in surface waters. In the depths there is not enough of it and the existence of biological populations is impossible. Below 50 m depth, the oxygen concentration begins to decrease catastrophically and reaches a mark already at a depth of 175 m. Here the activity of sulfate-reducing bacteria begins, which decompose organic matter coming from above, releasing hydrogen sulfide and carbon dioxide. Thanks to this, the waters of the Black Sea at a depth of 200 m and below are saturated with hydrogen sulfide.

In swamp biogeocenoses, the activity of methane bacteria plays a great role, which, by reducing organic carbon or carbon contained in carbonates, destroy organic compounds with the formation of methane. Methane, or swamp gas, rises to the surface and oxidizes, sometimes igniting, forming strange luminous clouds of bizarre figures in the night air. These bacteria also exist in the stomachs of ruminants, where they decompose plant matter.

Anaerobic decomposition processes are slower than aerobic ones. However, in nature they are of great importance, because they pass in hard-to-reach places and are additional suppliers of matter and energy, making them available to anaerobes. Thus, as a result of the activity of sulfate-reducing bacteria, hydrogen sulfide and carbon dioxide enter surface waters, where they are used by phytoplankton.

Biological decomposition always occurs during feeding, gradually, since none of the saprotrophs can complete decomposition. There are three stages of biological decomposition:

1. Grinding of detritus through physical or biological action;

2. Formation of humus and release of soluble organic matter

3. Slow mineralization of humus.

This confirms nature's general strategy of eating the pie so that it always remains whole.

Stage 1 of decomposition - grinding of detritus - occurs as a result of the feeding of phytophages. This includes herbivorous vertebrate and invertebrate organisms.

A. Herbivores, consuming vegetation, convert it into fats, proteins and sugars of animal origin. These substances decompose very quickly if the animals themselves turn into corpses. So, Odum carried out an experiment by placing the corpses of crabs in plastic bags and, for control, marsh grass. In 10 months, the crabs decomposed completely, and the grass only 60%.

B. The part of food not digested by herbivores, passing through the digestive tract, is thrown out in the form of excrement. This part of the detrital organic matter becomes the property of the links in the food chain of coprophages. Among coprophagous arthropods, a distinction is made between ectocoprophages, which develop in the dung heap itself, and telecoprophagous animals, which develop outside the dung heap. These are usually beetles that make balls of dung, roll them a considerable distance and bury them in the soil. Systematically, they belong to the family Geotrupiidae and Scarabaeidae. They hatch their larvae in these buried balls of dung. Burying manure has a beneficial effect on nature - it increases soil fertility and increases the growth of pasture plants. In addition, populations of infectious flies are suppressed, which are deprived of favorable places for laying eggs and decomposes helminths in cattle.

IN. Insects are coprophages, consuming manure and passing it through their intestines, increasing the degree of its fragmentation. The excrement of coprophages is easily processed by bacterial flora, and various fungi develop well on them. The excrement environment of dung invertebrates has high phosphatase activity. Therefore, there is the expression “fecal factor of coprophages,” which is of no small importance in the development of soil microflora.

Many soil invertebrates are important in the reduction of material. In the soil fauna, two groups of invertebrates stand out: arthropods and annelids.

Soil arthropods are divided into macroarthropods and microarthropods. Macroarthropods - larger than 2 mm - woodlice, beetles, centipedes, dipterans - mainly detritivores and their predators. Microarthropods - mainly mites and springtails - are also detritivores. Many detritivores cannot digest cellulose themselves. In this case, they resort to the help of microflora. Thus, the larvae of scarab beetles reproduce bacteria in their intestines. The bacteria feed on manure and multiply, which is what the larvae feed on. On the other hand, ammonifying bacteria develop in the ball of manure, which the larvae also feed on. Many detritivores release proteins and growth substances into detritus with their excrement, which stimulate the growth of microorganisms. In turn, by destroying bacteria, they stimulate accelerated growth of the bacterial population.

Annelids are a phylum that contains 8,000 species, of which two families are particularly important in soil life: Lumbricidae and Enchytraeidae.

Lumbricidae, or true earthworms, reach numbers of up to 500 individuals. per m 2. Charles Darwin was the first to attach great importance to the role of earthworms in soil-forming processes. He presented a huge amount of material about the extent of the worms’ activity, about the fact that they pass the entire soil of a meadow through their intestines in a few years. He did not exaggerate the importance of worms at all; rather, he even underestimated them, because... he based on the number of worms per 1 hectare of meadow being 60-133 thousand individuals, while it can reach up to 2 million per hectare, and a maximum of 20 million. It is estimated that on average per year all the worms in the world throw out as much soil to the surface as than can cover the entire land with a layer of three mm.

Enchytraeids ranging in size from 2 to 45 mm reproduce in the soil in huge quantities - up to 150 thousand per 1 sq.m.

The group of saprotrophs includes representatives of many families and genera of bacteria:

Morganella;
Klebsiella;
Bacillus;
Clostridia (Clostridium) and many others.

The result of the action of saprophytic organisms, obvious to humans, is the formation of rot - this is what the process of their feeding looks like. It is the rotting of organic material that is evidence that saprotrophs have taken over.

Mineralization of organic nitrogen (ammonification) and its transformation into inorganic compounds - such a key role in nature is assigned to saprophytic organisms.

Physiological processes

Saprotrophs, as one of the most numerous groups, have in their ranks representatives with very different physiological needs:

Anaerobes. For example, we can consider E. coli, which carries out its life processes without the participation of oxygen, although it can live in an oxygen environment.
Aerobes are bacteria involved in the decomposition of organic matter in the presence of oxygen. Thus, putrefactive diplococci and three-membered bacteria are present in fresh meat. At the initial stage, the content of ammonia (a waste product of putrefactive microflora) in meat does not exceed 0.14%, and in already rotten meat – 2% or more.
An example of spore-forming bacteria is Clostridia.
Non-spore-forming bacteria are Escherichia coli and Pseudomonas aeruginosa.

Despite the diversity of physiological groups, united according to the characteristics of saprophyte, the final products of the activity of these bacteria have almost the same composition:

cadaveric poisons (biogenic amines with a strong unpleasant cadaveric odor; as such, the toxicity of these compounds is low);
aromatic compounds such as skatole and indole;
hydrogen sulfide, thiols, dimethyl sulfoxide, etc.

Of all the listed decay products, the most dangerous and toxic to humans are the latter (hydrogen sulfide, thiols and dimethyl sulfoxide). They cause severe poisoning, even death.

Interaction

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Basic properties of saprophytes

Saprotrophs are heterotrophic organisms that use waste products, decomposition, and decay of other living organisms as nutrients. The process of food absorption occurs due to the release of a special enzyme onto the consumed product, which breaks it down.

Nutrition is the process of storing energy and nutrients. For normal existence, bacteria require a number of nutrients, such as:

nitrogen (in the form of amino acids);
proteins;
carbohydrates;
vitamins;
nucleotides;
peptides.

In laboratory conditions, for the propagation of saprophytes, autolysate from yeast, whey from milk, meat hydrolysates, and some plant extracts are used as nutrient media.

An indicative process of the presence of saprophytes in products is the formation of rot. The danger comes from the waste products of these microorganisms, as they are quite toxic. Saprophytes are a kind of orderlies in the environment.

The main representatives of saprophytes:

Pseudomonas aeruginosa (Pseudomonas);
Escherichia coli (Proteus, Escherichia);
Morganella;
Klebsiella;
Bacillus;
Clostridia (Clostridium);
some types of mushrooms (Penicilum, etc.)

Physiological processes of saprotrophic bacteria

Among these microorganisms are:

anaerobes (Escherichia coli, it can live in an oxygen-containing environment, but all life processes take place without the participation of oxygen);
aerobes (putrefactive bacteria that use oxygen in their life processes);
spore-forming bacteria (genus Clostridia);
non-spore-forming microorganisms (Escherichia coli and Pseudomonas aeruginosa).

Almost the entire variety of saprophytes, as a result of their vital activity, produces various cadaveric poisons, hydrogen sulfide, and cyclic aromatic compounds (for example, indole). The most dangerous to humans are hydrogen sulfide, thiol and dimethyl sulfoxide, which can lead to severe poisoning and even death.

Since by their nature these species are quite difficult to distinguish, the following classification arose:

Facultative saprophytes

The role of saprotrophs in human life

This type of bacteria plays a very significant role in the cycle of nature. At the same time, the objects for their nutrition are things that are, to one degree or another, important for humans.

Saprotrophs play a very important role in the processing of organic residues. Since any organism dies at the end of its life, the nutrient medium for these microorganisms will exist continuously. Saprophytes produce, in the form of products of their vital activity, many constituent substances necessary for the nutrition of other organisms (fermentation processes, transformation of sulfur, nitrogen, phosphorus compounds, etc. in nature).

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As we noted, along with plants and animals, thanks to which primary and, accordingly, secondary products are created, an extremely important role in biogeocenosis and biological circulation belongs to a variety of organisms classified as saprotrophs. They feed on detritus, i.e., products of decomposition of dead organisms, and ensure the mineralization of these substances. In addition to biological destruction, saprotrophic organisms also participate in other processes that are vital for plants, animals and biogeocenosis as a whole.

Saprotrophs primarily include a variety of microorganisms, mainly fungi (including molds), heterotrophic spore-forming and non-spore-forming bacteria, actinomycetes, algae, soil protozoa (amoeba, ciliates, colorless flagellates). In many ecosystems, bioreducers from among saprophagous animals are especially important, not only the mentioned microscopic ones, but also macroscopic ones (for example, earthworms).

It should also be borne in mind that the vital activity of a number of vertebrate animals is of considerable importance for the decomposition of dead organic substances, although they by no means belong to saprophages. Thus, not only individual groups of organisms, but their entire totality, or, as it is called, “biota,” participate in biological reduction.

Finally, we must not forget that the process of decomposition and mineralization, although biogenic in nature, also depends on abiotic conditions, since the latter create an environment for the activity of decomposer organisms.

Saprophytes are mainly concentrated in the soil. The number of microorganisms living in it is extremely large. In 1 g of podzolic soil in the Moscow region there are 1.2-1.5 million specimens. bacteria, and in the rhizosphere zone, i.e., the root zone of plants - up to 1 billion copies. The number of fungi and actinomycetes is hundreds of thousands and millions of individuals. The biomass of fungi, actinomycetes and algae in the surface soil horizon can reach 2-3 t/ha, and the biomass of bacteria - 5-7 t/ha. These numbers speak for themselves.

According to the fair conclusion of experts, saprophagous animals play a very significant role in the functioning of the plant-soil ecosystem block.

By participating in the mineralization of plant litter, saprophages contribute to the involvement of various organic compounds and chemical elements in the biological cycle, which ensures the next cycle of organic matter production.

The biocenotic role of this group of animals is not limited to the function of bioreducers. They, especially earthworms, are of great importance for the formation and transformation of soils and, finally, represent an important food resource for many vertebrate animals - moles, shrews, wild boars, badgers, woodcocks, thrushes and other animals and birds. By extracting earthworms and other soil invertebrates, they stir up the forest litter, dig into the ground and thereby contribute to the mechanical destruction of plant litter and its subsequent mineralization.

For this process, the large amount of excrement ejected by all animals is of no small importance. Here the matter is not limited to enriching the soil with organic substances. It is very important that excrement becomes a substrate for the development of a huge mass of microorganisms and small arthropod bioreducers, which, in turn, also spew out a lot of excrement. Soils are known that consist entirely of the excrement of Glomeris centipedes, which are distinguished by their extraordinary gluttony. It is estimated that one of the millipedes (limbed clubfoot) in the meadows eats all the rotting plant matter that the plants produce here every year.

The number of bacteria especially increases in the rhizosphere. It exceeds the number of microbes in the surrounding soil by hundreds and even thousands of times. The number of bacteria and their species composition vary greatly depending on the plant species and the chemistry of their root secretions, not to mention soil and climatic conditions.

The chemical specificity of the root secretions of higher plants determines the connections that exist between certain types of plants and mycorrhiza-forming fungi, such as boletus, which forms mycorrhiza on the roots of birch, or boletus, which is organically associated with aspen. Mycorrhizal fungi are extremely useful for higher plants, as they supply them with nitrogen, minerals and organic substances. A very important positive role in the life of higher plants is played by free-living and nodule nitrogen-fixing bacteria, which bind atmospheric nitrogen and make it available to higher plants. At the same time, the soil mycoflora contains many harmful species that produce toxic substances that suppress the growth and development of plants.

None of the types of saprotrophs is capable of completely decomposing a dead body. But in nature there are a large number of species of decomposer microorganisms. Their role in the decomposition process is different and in many terrestrial communities they functionally replace each other until complete mineralization of the dead organic substance occurs. Thus, the following sequentially participate in the decomposition of plant residues: mold fungi and non-spore-forming bacteria → spore-forming bacteria → cellulose myxobacteria → actinomycetes. Among them, some microorganisms constantly decompose dead creatures to the level of low molecular weight organic substances, which they, being saprophytes, use themselves. Other bioreducers convert dead tissue into minerals, whose chemical compounds are available for absorption by green plants. Bacteria appear to play a major role in the decomposition of animal soft tissue, while fungi are more important in the breakdown of wood. At the same time, different parts of plants and animals are destroyed at different rates.

As a result of the use of decomposing tissues of plants and animals by different types of organisms, a unique trophic system arises - a “detrital type” of energy flow, in which the accumulation and decomposition of dead matter occurs. Detrital food chains are very widespread in the biosphere. They typically function side by side with “pastoral-type” food chains starting with green plants and phytophages. Nevertheless, in these cases, one or another of the mentioned types predominates in the biocenosis, in particular it can be detrital. Thus, according to some estimates, in the biotic community of shallow sea water, only about 30% of all energy passes through detrital chains, while in a forest ecosystem with significant phytomass and relatively small zoomass, up to 90% of the energy flow passes through this kind of chain. In some specific ecosystems (for example, in the depths of the ocean and underground), where due to the lack of light the existence of chlorophyll-bearing plants is impossible, in general all food chains begin with detritus consumers.

In most detrital food chains, well-coordinated functioning of both groups of saprotrophs is observed; saprophagous animals, by their activity aimed at dismembering dead plants and animals, create conditions for the intensive “work” of saprophytes - bacteria, fungi, etc.

In this complex, interconnected process, it is necessary to specially emphasize the important role of animals, especially since it was clearly underestimated by many scientists, who limited the corresponding calculations to only earthworms and some other invertebrates. Meanwhile, the results of recent studies have demonstrated the very significant importance of the activities of mammals, in particular mouse-like rodents, for the formation and decomposition of detritus. In the colonies of common voles (Fig. 124) in the Central Chernozem Reserve, the remains of nibbled grasses dry and mineralize faster than plants that gradually die off on the root. Voles fertilize the soil with their corpses and secretions and thus contribute to the development of microorganisms. Their excrement is almost entirely mineralized during the first two years. A special microclimate arises in vole colonies, which affects the intensity of biotic processes and the rate of abiogenic mineralization of plant litter, which is especially noticeable in steppe biogeocenoses, since destruction processes there are controlled mainly by climatic factors. Ultimately, the activity of voles leads to a sharp imbalance in the accumulation and mineralization of litter, so that during the summer and autumn the destruction of dead remains prevails over their accumulation.

Rice. 124. Common vole. Photo

An extremely important manifestation of the impact of bioreducing saprotrophs on organic residues must be recognized as those processes that occur in the soil and entail its enrichment with nutrients.

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Xylotrophs. Wood decomposition is one of the main links in the biological cycle of substances in nature.

Depending on the type of decomposing compounds, mushrooms are divided into two groups.

1. Mushrooms use only the carbohydrate complex, in particular cellulose, and lignin is not broken down. This type of destruction (decomposition) is called brown or destructive rot. The wood loses strength and crumbles into separate cubes. Representatives: fringed polypore (Fomitopsis pinicola), scaly polypore (Polyporus squamosus), oak sponge (Daedalea quercina), etc.

2. Mushrooms use mainly lignin. In this case, the wood splits into individual white fibers. This rot is called white rot or corrosive rot. Representatives: autumn honey fungus (Armillaria mellea), true polypore (Fomes fomentarius), flat polypore (Ganoderma applanatum), oyster mushroom (Pleurotus).

The greatest amount of wood is needed by mushrooms during the formation of spores. On average, the formation of one fruiting body of a mushroom requires as much nitrogen as is contained in 6 kg of wood. For the formation of spores by one fruiting body of the flat polypore, 35 kg of wood is required during the season. The needs of a real tinder fungus are even greater. For the formation of spores by one fruiting body within 20 days, 41 kg of wood is required. Along with the decomposition of wood, another important process occurs - soil formation, since dark-colored huminopodic compounds accumulate in the hyphae of fungi as a result of the decomposition of lignin.

The decomposition of wood occurs in stages, the destruction of substances occurs gradually, and some species are replaced by others (succession). According to S.A. Vaksman’s scheme, this process can be represented by the following stages.

1. Fast-growing groups of zygomycetes, together with bacteria, use water-soluble wood compounds.

2. Polysaccharides, such as starch, hemicellulose, are utilized by marsupial and anamorphic fungi.

3. Decomposition of lignin by wood-destroying fungi. First, aphyllophoroid (in particular, tinder) basidiomycetes settle, and then agaricoid basidiomycetes and gasteromycetes, which complete the decomposition of the wood.

Litter saprotrophs. The name itself speaks about the location and functional significance of the fungi of this ecological group. Litter decomposition is a very important process in the life of ecosystems. It is known that 25...60% of forest litter consists of leaves and needles, which differ from wood residues in chemical composition. Almost all taxonomic groups of fungi participate in the decomposition of litter, but ascomycetes, zygomycetes, and anamorphic fungi dominate. Pigmented anamorphic mushrooms are of great interest. Sometimes there are 70...90 and even 100%. Among macromycetes, the most common are mushrooms of the genus Marasmius, Mycena, Collybia, Clitocybe, and Geastrum. The mycelium of litter saprotrophs can withstand sharp fluctuations in temperature and humidity.

Processes occurring during litter decomposition:

mineralization of nitrogenous compounds. This process involves bacteria - ammonifiers and fungi of the genera Mucor, Aspergillus, Trichoderma. Protein decomposition occurs. The main result is the conversion of combined nitrogen into free ammonia: N-NH 3 ;
The decomposition of carbon compounds to CO 2 and H 2 O is also carried out by certain groups of bacteria and fungi.

Humus saprotrophs. Humic saprotrophs form a group of species involved in the decomposition of soil humus. Their mycelium is located in the lower layer of forest litter and in the upper soil horizon, but they can grow in completely bare areas devoid of litter. These are mainly agaricoid basidiomycetes and gasteromycetes. These mushrooms are found in open spaces, for example, tall umbrella mushroom (Macrolepiota procera), blushing umbrella mushroom (Chlorophyllum rhacodes), champignons (Agaricus), earth stars (Geastrum), puffballs (Lycoperdon).

Carbotrophs. Carbotrophs settle in old fireplaces and conflagrations, and occupy pyrogenic habitats. On the one hand, they can be considered as the result of biochemical adaptation to pyrogenic habitats. On the other hand, this is a move away from competitors into an ecological niche inaccessible to them. The substrate is a mixture of mineral soil particles with charred wood residues. Such a nutrient medium contains pure carbon with a small admixture (2...3%) of polymeric carbohydrates.

A clear colonization of the substrate is observed. After two weeks, thermophilic species of ascomycetes appear, for example Sordaria, Pyronema, then species with antagonistic activity, for example species of the genus Peziza. At the last stages of destruction of the coal substrate, coal flake (Pholiota carbonaria), cinder myxomphalia (Myxomphalia), and pinnate psathyrella (Psathyrella pennata) grow. By this time, the soil microbiota is usually restored. Thus, carbotrophs are a specific group of fungi, functionally aimed at preparing the substrate for its further colonization by higher plants.

Coprotrophs. Coprotrophs utilize organic substances found in animal excrement (copros - manure). The substrate is rich in organic matter. For them, this source of nutrition is the only one and therefore determines their distribution in nature. Coprotrophs are more often found in livestock manure than in wild animal excrement. This determined their confinement to populated areas.

Fungi that settle on manure have specific characteristics. First of all, fungal spores must be resistant to elevated temperatures and the effects of the digestive system of animals. Basically, coprotrophs include fungi of the mucor family (Mukor, Pilobolus), as well as macroscopic fungi - dung beetle (Coprinus), panaeolus (Panaeolus). Living on a specific substrate has led to interesting features that facilitate the spread of spores:

spores are forcefully ejected from the fruiting bodies (dung beetle) or from the sporangiophore (pilobolus);
the spore mass is carried above the substrate (mukor);
spores or fruiting bodies have appendages and are carried by animals and birds (chaetomium, lophotrichum).

Mycotrophs. The decomposition and mineralization of fungal residues in nature is carried out by fungi - mycotrophs, both micromycetes and macromycetes. Mycotrophs are distributed everywhere, in different climatic zones. Quite rarely in forests, on the fruiting bodies of russula mushrooms, cap mushrooms grow on the second floor, for example, Asterophora lycoperdoides.

Conclusion. Judging by the characteristics of the ecological groups of fungi, they have adapted to living in all communities, are in close connection with other organisms and are active participants in the soil-forming process, as well as the cycle of carbon, nitrogen and phosphorus in nature.

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Decomposers (also destructors, saprotrophs, saprophytes, saprophages) are microorganisms (bacteria and fungi) that destroy dead remains of living beings, converting them into inorganic compounds and the simplest organic compounds.
Decomposers differ from detritivores (animals and protists) primarily in that they do not leave solid undigested residues (excrement). In ecology, detritivorous animals are traditionally classified as consumers (see, for example, Bigon, Harper, Townsend, 1989). At the same time, all organisms emit carbon dioxide and water, and often other inorganic (ammonia) or simple organic (urea) molecules and thus take part in the destruction (destruction) of organic matter.
Ecological role of decomposers
Decomposers return mineral salts to the soil and water, making them available to autotrophic producers, and thus closing the biotic cycle. Therefore, ecosystems cannot survive without decomposers (unlike consumers, which were probably absent from ecosystems during the first 2 billion years of evolution, when ecosystems consisted of only prokaryotes).
Abiotic and biotic factors regulating ecosystems
Research by N.I. Bazilevich et al. (1993) established that in terrestrial ecosystems there are two groups of factors regulating destructive processes that play a very significant role in the biological cycle.
These are primarily abiotic factors - leaching of soluble compounds, photochemical oxidation of organic matter and reactions of its mechanical destruction due to freezing and thawing.
These factors are most pronounced in the above-ground layers of ecosystems, and biotic factors - in the soil. Abiotic factors of destruction are typical for arid and semiarid landscapes (deserts, steppes, savannas), as well as for continental highlands and polar landscapes.
Biotic factors of destruction are primarily saprotrophic organisms (invertebrate and vertebrate animals, microorganisms) inhabiting the soil and litter, and the leading factor in terrestrial landscapes is mainly soil microflora.

Organisms can survive only at the expense of the host, feeding on the tissues of a living creature or plant. The habitat is chosen inside or outside the host: foliage, fruits, dermis, internal organs, mucous membrane. Almost all types of microorganisms are dangerous to humans. Viruses threaten life, helminths poison the body with toxic secretions, fungus destroys microflora and causes necrosis. In some cases, lack of medical care leads to death.

Fact! When infected with parasites, therapeutic treatment is always required. This can be a traditional method or medicinal or surgical intervention.

Living organisms related to saprophytes

Saprophytes are bacteria and microorganisms that feed on the remains of animals and plants. Being lower beings, almost all microorganisms are safe for humans. But there are also those that can cause harm, for example, dust mites. This inhabitant lives on any surface and feeds on dust. Another example of harmful bacteria is E. coli, which causes severe pathologies when it enters a living organism. By causing an infectious disease, the bacillus can provoke pneumonia, meningitis, sepsis - diseases with a high risk of death.

Important! The habitat of protozoan species is dead carcasses of cattle and other animals. Even though organisms do not feed on living tissue, the food must still be organic in nature. Microorganisms never settle in chemicals and other substances - this environment is destructive for them. That is why preventive measures against ticks and E. coli include hand washing and wet cleaning using soap solutions.

The life cycle of organisms is not complex. In the process of symbiosis, a viable individual is formed, capable of further reproduction by spores.