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In the discipline "Ecology of microorganisms"

“Method of microscopic observations. Features of microscopy of microorganisms. Uncultivated forms of bacteria. Luminescent-microscopic methods. The use of various dyes. Immunofluorescence methods»

1. Introduction

2. Method of microscopic observations

3. Features of microscopy of microorganisms

4. Unculturable forms of bacteria

5. Luminescent microscopic methods. Immunofluorescence methods

6. Use of various dyes

Introduction

Ecology of microorganisms is a branch of general ecology that studies the habitats of microbes and their ecological relationships. The main provision is the concept of the dominance of microbes in the creation of the Earth's biosphere and the subsequent maintenance of its ecological balance. This concept is based on the idea of ​​microbes as the only living inhabitants of the Earth in the period between 4×10 9 -0.5×10 9 years ago, on the ubiquitous distribution of microbes in the biosphere, the predominance of microbial biomass over the total biomass of plants and animals, the ability of microbes to transform any organic and inorganic substances and include chemical elements and energy in more and more cycles of the circulation of substances and energy, as well as independently accumulate new biomass and carry out, although sharply limited, but a complete cycle of nitrogen, carbon and some other elements, maintain radiation (thermal) balance of the Earth. Such an important role of microbes is ensured by the mass character of populations, high rates of their growth and reproduction, the ability to move and stay dormant for a long time, and relatively high resistance to damaging factors. external environment, extreme diversity in physiological needs, small size and mass, which determine the possibility of their wide migration with air, water and biogenic flows. Applied ecology of microorganisms solves the following problems:

1) Protection of microbial populations and biocenoses involved in maintaining the ecological balance (nitrogen-fixing, ammonifying, nitrifying, etc.) from adverse effects economic activity person;

2) Prevention of microbial degradation of live and inanimate nature and various anthropogenic materials (for example, the prevention of diseases in humans, animals, plants, conservation food products, industrial materials, etc.);

3) Microbial synthesis of materials and substances necessary for human society (eg, microbial protein synthesis);

4) Protection of the Earth's biosphere from artificial mutants and the introduction of life from space and the removal of life from Earth into space;

5) An important section of the ecology of microorganisms is the study of environmental relationships.

Method of microscopic observations

Microscopic observations- methods of studying very small, indistinguishable objects with the naked eye using microscopes. Widely used in bacteriological, histological, cytological, hematological and other studies.

Conventional light microscopy is designed to study stained preparations on glass slides. Light microscopy can be used to study the mobility of microorganisms. For this, the hanging drop method is used. A small drop of microbial suspension is applied to the middle of the coverslip. A glass slide with a recess (“hole”), the edges of which are smeared with petroleum jelly, is carefully placed on a cover slip so that a drop of the test liquid is in the center of the recess, pressed firmly against the glass and quickly turned upside down. To study the preparation, an immersion objective is used, which is immersed in immersion oil on a cover glass.

In addition to light, there are phase-contrast, dark-field (ultramicroscopy), luminescent, polarizing, ultraviolet and electron microscopy.

Phase contrast microscopy is based on the interference of light: transparent objects that differ in refractive index from their surroundings appear either as dark against a light background (positive contrast) or as light against a dark background (negative contrast). Phase contrast microscopy is used to study living microorganisms and cells in tissue culture.

Dark-field microscopy (ultramicroscopy) is based on the scattering of light by microscopic objects (including those whose dimensions are smaller than the resolution limit of a light microscope). With dark-field microscopy, only rays of light scattered by objects under side illumination (similar to the Tyndall effect, an example of which is the detection of dust particles in the air when illuminated by a narrow beam of sunlight) enter the lens. Direct rays from the illuminator do not enter the lens. Objects under dark-field microscopy appear brightly glowing against a dark background. Dark-field microscopy is used mainly for the study of spirochetes and the detection (but not the study of morphology) of large viruses.

Luminescent microscopy is based on the phenomenon of luminescence, i.e., the ability of certain substances to glow when irradiated with the short-wavelength (blue-violet) part of visible light or ultraviolet rays with a wavelength close to visible light. Fluorescent microscopy is used for diagnostic purposes to observe live or fixed microorganisms stained with luminescent dyes (fluorochromes) in very high dilutions, as well as to detect various antigens and antibodies using the immunofluorescence method.

Polarization microscopy is based on the phenomenon of light polarization and is designed to detect objects that rotate the polarization plane. It is mainly used to study mitosis.

Ultraviolet microscopy is based on the ability of certain substances (DNA, RNA) to absorb ultraviolet rays. It makes it possible to observe and quantify the distribution of these substances in the cell without special staining methods. Ultraviolet microscopes use quartz optics that transmit ultraviolet rays.

Electron microscopy differs fundamentally from light microscopy both in the structure of an electron microscope and in its capabilities. In an electron microscope, instead of light beams, a stream of electrons in a deep vacuum is used to build an image. The lens that focuses the electrons is the magnetic field created by the electromagnetic coils. The image in an electron microscope is observed on a fluorescent screen and photographed. As objects, ultrathin sections of microorganisms or tissues with a thickness of 20-50 nm are used, which is much less than the thickness of viral particles. The high resolution of modern electron microscopes makes it possible to obtain a useful magnification of millions of times. With the help of an electron microscope, the ultrafine structure of microorganisms and tissues is studied, and immune electron microscopy is also carried out.

Features of microscopy of microorganisms

A feature of microscopy of microbes is the use of an exclusively immersion system consisting of an object under study, immersion oil and an objective. The advantage of this system is that between the object on the glass slide and the front lens of the objective there is a medium with the same refractive index (cedar, vaseline oil, etc.). Thanks to this, the best illumination of the object is achieved, since the rays are not refracted and enter the lens. In conventional light microscopy, the observed object (including microbes) is examined in transmitted light. Since microbes, like other biological objects, have low contrast, they are stained for better visibility. In order to expand the boundaries of visibility, other types of light microscopy are used. Dark-field microscopy is a method of microscopic examination of objects that do not absorb light and are poorly visible with the bright field method. In dark-field microscopy, objects are illuminated by oblique rays or a side beam of light, which is achieved using a special condenser - the so-called dark-field condenser. In this case, only rays scattered by objects in the field of view enter the microscope lens. Therefore, the observer sees these objects glowing brightly against a dark background. Dark-field microscopy is used for in vivo study of treponema, leptospira, borreliae, flagellar apparatus of bacteria. Phase-contrast microscopy is a method of microscopic observation of transparent, uncolored, non-absorbing objects based on image contrast enhancement. Transparent uncolored objects (including living microorganisms) differ from the environment in terms of refractive index, do not absorb light, but change its phase. These changes are not visible to the eye. In phase contrast microscopy, light that is not absorbed by an object passes through a so-called phase ring deposited on one of the objective lenses. The phase ring shifts the phase of this transmitted light by a quarter wavelength and reduces its intensity. The passage of direct light not absorbed by the object through the phase ring is provided by the annular diaphragm of the condenser. Rays, even slightly deflected (scattered) in the preparation, do not fall into the phase ring and do not undergo a phase shift. As a result, the phase difference between the deflected and non-deflected beams is enhanced, giving a contrast image of the preparation structure. Phase contrast microscopy is used for in vivo study of bacteria, fungi, protozoa, plant and animal cells.

Uncultivated forms of bacteria

Many types of Gram-negative bacteria, including pathogenic ones (Shigella, Salmonella, Vibrio cholerae, etc.), have a special adaptive, genetically regulated state, physiologically equivalent to cysts, into which they can pass under the influence of adverse conditions and remain viable for up to several years. The symbiosis of several types of bacteria used in medicines helps a lot in the treatment of VVD (vegetovascular dystonia) and other diseases.

The main feature of this condition is that such bacteria do not multiply and therefore do not form colonies on a dense nutrient medium. Such non-reproducing, but viable cells are called non-culturable forms of bacteria (NFB). NFB cells in an uncultivated state (NS) have active metabolic systems, including systems for electron transfer, protein and nucleic acid biosynthesis, and retain virulence. Their cell membrane is more viscous, the cells usually take the form of cocci, have a significantly reduced size. NFBs are more stable in the environment and therefore can survive in it for a long time (for example, Vibrio cholerae in a dirty water body), maintaining an endemic state this region(reservoir).

To detect NFB, molecular genetic methods (DNA-DNA hybridization, CPR) are used, as well as a simpler method of direct counting of viable cells. For this purpose, a small amount of nutrients (yeast extract) and nalidixic acid (to suppress DNA synthesis) are added to the test material for several hours.

Cells absorb nutrients and increase in size, but do not divide, so such enlarged cells are clearly visible under a microscope and can be easily counted. For these purposes, cytochemical methods (formation of formazan) or microautoradiography can also be used. Genetic mechanisms, which determine the transition of bacteria into NS and their reversion from it, are not clear.

Luminescent-microscopic methods.

Immunofluorescence methods.

Luminescent microscopy is based on the property of certain substances to give luminescence - luminescence in UV rays or in the blue-violet part of the spectrum. Many biological substances such as simple proteins, coenzymes, some vitamins and medicines, have their own (primary) luminescence. Other substances begin to glow only when special dyes are added to them - fluorochromes (secondary luminescence). Fluorochromes can be diffusely distributed in a cell or selectively stain individual cell structures or certain chemical compounds of a biological object. This is the basis for the use of luminescent microscopy in cytological and histochemical studies. With the help of immunofluorescence in a luminescent microscope, viral antigens and their concentration in cells are detected, viruses are identified, antigens and antibodies, hormones, various metabolic products, etc. are determined. In this regard, luminescent microscopy is used in the laboratory diagnosis of infections such as herpes , mumps, viral hepatitis, influenza, etc., are used in the rapid diagnosis of respiratory viral infections, examining prints from the nasal mucosa of patients, and in the differential diagnosis of various infections. In pathomorphology, using luminescent microscopy, malignant tumors are recognized in histological and cytological preparations, areas of ischemia of the heart muscle are determined in the early stages of myocardial infarction, amyloid is detected in tissue biopsies, etc.

In laboratory practice, the Koons immunofluorescent method is also used, when, with the help of a fluorescent dye attached to an antibody molecule, the antigen-antibody reaction becomes visible under a fluorescent microscope.

Unlike other serological reactions, when the connection of an antigen with an antibody is judged by the secondary effect it causes (agglutination, precipitation, etc.), the immunofluorescence method allows you to directly observe the ongoing reaction and, therefore, judge the presence and localization of the antigen.

Currently, the enzyme immunoassay method, which has high sensitivity and versatility, is becoming widespread. This method is based on the determination of antigens using an enzyme-bound immunosorbent. This reaction between antigen and antibody is called ELISA (enzyme-linked immunosorbent assay).

For example, if an antigen is to be detected in a cell in the presence of a corresponding homologous antibody, one can link the enzyme covalently to the antibody and then react with the antigen with the enzyme labeled antibody.
The most sensitive, which allows detecting a low content of antigens (0.5 ng / ml), is the radioimmune method, but it requires special equipment.

These methods have a number of advantages over bacteriological. These are express diagnostic methods that allow you to determine the antigens of pathogens within a few minutes or hours.

The use of various dyes

Staining of microorganisms is the most common set of methods and techniques in microbiology used to detect and identify microorganisms using a microscope. In their native (natural) state, bacteria have the same refractive index as glass, so they are invisible under microscopic examination. The staining of microorganisms makes it possible to study the morphological features of microbes, and sometimes to accurately determine their type, for example, some microbes - the same in morphology - are stained differently using the same complex staining methods.

The coloring of microorganisms is a physicochemical process of combining the chemical components of the cell with the paint. In some cases, various parts of a microbial cell (nucleus, cytoplasm) are selectively stained with various dyes. The most suitable for staining microorganisms are aniline paints, mainly basic and neutral, acidic paints are less suitable.

The preparation of a colored preparation includes a number of steps:

1) preparation of a smear;

2) drying the smear;

3) smear fixation;

4) coloring;

5) drying.

A smear is prepared on clean glass slides, in the middle of which a small drop of water is applied and the test material is placed in it using a bacteriological loop. The material is distributed on the glass evenly thin layer, smear size -1-2 cm 2.
The drug is usually dried at room temperature in air. To speed up drying, it is allowed to heat the smear in a stream of warm air high above the burner flame.

The dried smear is subjected to fixation, in which the smear is attached to the glass (fixed) and microbes become more susceptible to staining. There are many ways to fix. The simplest and most common is heat fixation - heating on a burner flame (the drug is carried out several times through the hottest part of the burner flame). In some cases, they resort to fixing with liquids (ethyl or methyl alcohol, acetone, a mixture of equal volumes of alcohol and ether - according to Nikiforov). After fixation, the smear is stained. The amount of paint applied to the preparation should be such as to cover the entire surface of the smear. At the end of the staining period (2-5 minutes), the paint is drained and the preparation is washed with water.

There are simple, complex and differential ways to stain microbes. With simple coloring, one paint is usually used, most often red - magenta, or blue - methylene blue. Magenta dyes faster (1-2 minutes), methylene blue - slower (3-5 minutes). Fuchsin is prepared in the form of a concentrated carbolic solution (Ziel's fuchsin), which is very resistant and can be dyed for many months. Methylene blue is prepared in advance in a saturated alcohol solution, which is stable and can be stored for a long time.
Complex staining methods using two or more dyes are valuable methods used in the microbiological diagnosis of infectious diseases.

Greatest practical value It has a Gram stain and a Ziel stain.
The Ziehl stain is the main method for staining acid-fast bacteria. Two dyes are used here: Ziehl carbolic fuchsin and methylene blue. Acid-fast bacteria stained red, all non-acid-fast bacteria stained blue.

The Gram method is a method of staining microorganisms for research, which allows differentiating bacteria according to the biochemical properties of their cell wall. Gram stain has great importance in the taxonomy of bacteria, as well as for the microbiological diagnosis of infectious diseases.

Gram-positive coccal (except for representatives of the genus Neisseria) and spore-bearing forms of bacteria, as well as yeast, they are painted in blue-black (dark blue) color.

Many non-spore-bearing bacteria are gram-negative, they stain red, the cell nuclei become bright red, the cytoplasm becomes pink or crimson.

Gram stain refers to a complex method of staining when a smear is exposed to two dyes, one of which is the main one and the other is an additional one. In addition to dyes, bleaching agents are used for complex methods of coloring: alcohol, acids, etc.

For Gram staining, aniline dyes of the triphenylmethane group are most often used: gentian, methyl violet or crystal violet. Gram-positive Gram (+) microorganisms give a strong connection with the indicated dyes and iodine. At the same time, they do not discolor when exposed to alcohol, as a result of which, with additional staining with fuchsin Gram (+), microorganisms do not change the originally adopted purple color.

Gram-negative Gram (-) microorganisms form a compound easily destroyed by alcohol with basic dyes and iodine. As a result, the microbes become discolored and then stained with magenta, turning red.

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Description of the presentation on individual slides:

1 slide

Description of the slide:

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Description of the slide:

Ecology of microorganisms studies the relationship of microorganisms with each other and the environment. Microorganisms are found in soil, water, air, plants, humans and animals, and even in space

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Microorganisms - component biocenosis, i.e. a set of animals, plants and microorganisms inhabiting a biotope - a piece of land or a reservoir with homogeneous living conditions. The community of microorganisms living in certain areas of the environment is called microbiocenosis.

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Description of the slide:

The spread of microbes in the environment Soil microflora Water microflora Air microflora Food microflora Microflora of plant medicinal raw materials, phytopathogenic microbes Microflora of industrial, household and medical facilities The role of microbes in the circulation of substances in nature

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Description of the slide:

1. Soil microflora The soil is inhabited by a variety of microorganisms: bacteria, fungi and protozoa. The number of bacteria in the soil reaches 10 billion cells per 1 year. There are relatively few microorganisms on the soil surface, because they are detrimental to UV rays, drying and other factors. The composition of the soil microflora depends on its type, humidity, etc. The soil is a habitat for pathogenic spore-forming rods (causative agents of anthrax, botulism, tetanus, gas gangrene), they are able to persist for a long time, and some even multiply in the soil. There are also fungi in the soil. They participate in the transformation of nitrogen compounds, release biologically active substances, antibiotics and toxins. Toxin-forming fungi, getting into human food, cause intoxication - mycotoxicosis and aflatoxicosis.

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Description of the slide:

2. Water microflora Various bacteria are found in the waters of fresh water bodies: rod-shaped (pseudomonas), cocci-shaped (micrococci) and convoluted. Water pollution with organic substances is accompanied by an increase in anaerobic and aerobic bacteria, as well as fungi. The microflora of water plays the role of an active factor in the process of its self-purification from organic waste, which is utilized by microorganisms. Together with polluted storm, melt and sewage, representatives of the normal microflora of humans and animals (E. coli, enterococci) and pathogens of intestinal infections (typhoid fever, paratyphoid fever, dysentery, cholera, etc.) enter lakes and rivers. Thus, water is a factor in the transmission of pathogens of many infectious diseases. The water of artesian wells practically does not contain microorganisms.

7 slide

Description of the slide:

3. Air microflora Microorganisms enter the air from the respiratory tract and with drops of human and animal saliva. Coccoid and rod-shaped bacteria, bacilli, clostridia, actinomycetes, fungi and viruses are found here. Sunlight and other factors contribute to the death of air microflora. More microorganisms are present in the air major cities and indoors.

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4. Food microflora food products can be contaminated by various microorganisms. At a low storage temperature of meat and meat products, even in frozen meat, microbes capable of reproduction under psychrophilic conditions (pseudomonas, proteus, etc.) may predominate. Food products contaminated with microorganisms can cause a wide variety of food poisoning and intoxication, as well as infectious diseases such as anthrax, brucellosis, and tuberculosis.

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Description of the slide:

5. Microflora of herbal medicinal raw materials, phytopathogenic microbes Herbal medicinal raw materials can be contaminated with microorganisms in the process of its production: infection occurs through water, non-sterile pharmaceutical glassware, air industrial premises and the hands of the staff. Insemination also occurs due to the normal microflora of plants and phytopathogenic microorganisms - pathogens of plant diseases. Phytopathogenic microorganisms are able to spread and infect a large number of plants.

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6. The role of microbes in the circulation of substances in nature Organic compounds of plant and animal origin are mineralized by microorganisms to carbon, nitrogen, sulfur, phosphorus, iron and other elements.

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Impact of environmental factors on microbes Physical, chemical and biological environmental factors have different effects on microorganisms: bactericidal - leading to cell death; bacteriostatic - overwhelming reproduction of microorganisms; mutagenic - changing the hereditary properties of microbes.

12 slide

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Effect of Temperature Microorganisms tolerate low temperatures well. They can be stored frozen for a long time, including at a liquid nitrogen temperature of -1730. The temperature factor is taken into account during sterilization. Vegetative forms of bacteria die at t 600 for 20-30 minutes, spores in an autoclave at 1200 under steam pressure.

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desiccation Dehydration causes disruption of the functions of most micro-organisms. The causative agents of gonorrhea, meningitis, cholera, dysentery, and other pathogenic microorganisms are most sensitive to drying. More resistant are bacteria protected by mucus sputum. Thus, tuberculosis bacteria in sputum can withstand drying up to 90 days. Bacterial spores are especially resistant (anthrax spores remain in the soil for centuries). To prolong viability, when preserving microorganisms, lyophilization is used - drying under vacuum from a frozen state. Freeze-dried cultures, o/w, and immunological preparations are stored for a long time (for several years) without changing their original properties.

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Description of the slide:

Effect of radiation Ionizing radiation is used to sterilize disposable plastic microbiological tableware, nutrient media, dressings, medicines, etc. m / o already h / o a short period of time. UVR is used for air disinfection in MO (bactericidal lamps)

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Influence of chemicals Chem. in-va have a different effect on m / o: they serve as a source of nutrition, do not have any effect, stimulate or inhibit growth, cause death. Antimicrobial chem. in-va are used as antiseptic and disinfectants, tk. have bactericidal, virucidal, fungicidal action, etc.

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Influence of biological factors Microorganisms are in various relationships with each other. The coexistence of two different organisms is called symbiosis. There are several options for useful relationships: Metabolism - the relationship of m / o, in which one of them uses for its life the waste products of the other. Mutualism is a mutually beneficial relationship between different organisms. Commensalism - cohabitation of individuals various kinds in which one species benefits from the symbiosis without harming the other. Commensals are bacteria - representatives of the normal human microflora. Satellism is an increase in the growth of one type of m / o under the influence of another type of m / o. For example, colonies of yeast or sarcin, releasing metabolites into the nutrient medium, stimulate the growth of colonies of other m/o around them.

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Sanitary microbiology A branch of medical microbiology that studies m / o contained in the environment and can have an adverse effect on human health. It develops microbiological indicators of hygienic regulation, methods for monitoring the effectiveness of disinfection of environmental objects, and also detects pathogenic, opportunistic and sanitary-indicative microorganisms in environmental objects.

19 slide

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Detection of pathogenic m/o allows assessing the epidemiological situation and taking appropriate measures to combat and prevent infectious diseases. Opportunistic m / o can cause purulent-inflammatory processes in a weakened body. In addition, they can get on food, multiply and accumulate in them, causing food poisoning of microbial etiology. Sanitary indicative m/o are used to indirectly determine the possible presence of pathogenic m/o in environmental objects. Their presence indicates contamination of the object with excretions of humans and animals, because. they reside permanently in the same organs as pathogens and share a common route of excretion into the environment.

20 slide

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1. Sanitary indicative soil bacteria are Escherichia coli, Clostridium perfringens, Streptococcus feacalis, thermophilic bacteria. The presence of the first three is used to judge the degree of fecal contamination of the soil. 2. The health indicator microorganism for water is E. coli (Escherichiae coli). Good-quality drinking water must meet the requirements State standard: Suitable - 1 ml of water contains no more than 100 microorganisms; doubtful - 1 ml of water contains 100 - 450 microorganisms; unsuitable - 1 ml of water contains more than 500 microorganisms. 3. Sanitary-indicative microorganisms for air are Staphylococcus aureus and hemolytic streptococci (Staphylococcus aureus, group Streptococcus viridans and Streptococcus haemolyticus).

21 slide

Description of the slide:

Soil microflora. Soil microflora.
Ideas about the number and biomass of microorganisms in the soil (microbial pool),
changed dramatically as research methods improved.
Usage
direct
microscopic
methods,
especially
method
luminescence microscopy, made it possible to take into account with great completeness
the number of the main groups of microorganisms.

Soil microflora.

The soil
contains
huge
reserves
microbial biomass, over 90% of its
accounted for by spores and mycelium of fungi.
Maximum
concentration
bacterial cells and the greatest length
mycelium
mushrooms
different
forest
litter and top humus
soil horizons.
In 1 g of soil, the number of bacteria is
from 1 to 10 mld, sometimes even a few
ten billion cells, and the total length
mushroom hyphae equals hundreds and thousands
meters.
Total wet weight of microorganisms
can be in the upper 25cm layer
soil up to 10 t/ha.
Down the profile the number of bacteria and
the length of the mycelium of fungi decreases.
Major stocks of microbial biomass
concentrated in mineral horizons
soils.
The higher the fertility of the soil, the richer and
its microbiocenosis is more diverse.

Soil microorganisms are very diverse:
bacteria
bacilli
Spirochetes
Cytophages
actinomycetes
Mycoplasmas
archaebacteria
Viruses and phages
Mushrooms
Seaweed
soil protozoa

Microorganisms carry out deep transformation
organic and mineral mass of the soil (as well as mineral
rock materials).

Ecology of soil microorganisms.

Microorganisms play an important role in maintaining stability
terrestrial ecosystems and the Earth's biosphere as a whole.

Ecology of soil microflora

microbial
community
soil
consists of
from
big
numbers
specialized populations in dynamic equilibrium.
Different groups of microorganisms have different requirements for
environmental conditions (content and composition of organic matter, heat and
moisture, redox conditions, environmental reaction,
salt concentration).
Changes in external conditions in the annual cycle and interpopulation
interactions lead to fluctuations in abundance, biomass and
taxonomic composition of microbial complexes (successions of microbial
communities).
In addition, to
distribution
microbiocenoses
applicable law
geographical
zoning.

Geochemical role of soil microorganisms.

The effects of microbial activity go far beyond
the limits of the soils they inhabit and largely determine the properties
sedimentary rocks, composition of the atmosphere and natural waters, geochemical
the nature of elements such as carbon, nitrogen, sulfur, phosphorus, oxygen,
hydrogen, calcium, potassium, iron.

The role of soil microorganisms

Microorganisms are polyfunctional in biological properties.
relation and are capable of carrying out such processes with the biosphere and soils,
which are inaccessible to plants and animals, but which are
an essential part of the biological cycle of energy and substances.
These are the process of nitrogen fixation, the oxidation of ammonia and hydrogen sulfide,
precipitation of iron and manganese compounds from solution.
This also includes microbial synthesis in the soil of many vitamins, enzymes,
amino acids and other physiologically active elements.

The role of soil microorganisms.

Bacteria, like plants, can synthesize organic
matter, but do not use the energy of the sun.
The primary soil-forming process on Earth was carried out
(and is carried out now) by microorganisms long before the appearance of
higher plants.
Bacteria and fungi are very strong destroyers
primary minerals and rocks - agents of biological
weathering.

The role of microorganisms.

A unique feature of microorganisms is the ability
bring the processes of decomposition of organic matter to full
mineralization. This is the fundamental difference
between the role of microorganisms in the biosphere and the role of plants and
animals.
Synthesis of physiologically active compounds, humus formation and
complete mineralization of organic residues - the main function
microorganisms in soil processes and biological
circulation.

Microbes carry out cleaning of soils from some organic and
inorganic contaminants, thus contributing to
improvement of soils and the ecosystem as a whole. microorganism decompose
hydrocarbons (petroleum, fuel oil, gasoline, kerosene, lubricating oils),
pesticide, polymer materials, excess nitrogen compounds
(especially nitrates), oxidation of carbon monoxide.

susceptibility of microorganisms.
Microorganisms are sensitive indicators that react sharply to various
changes in the environment. This allows them to be used for diagnostic purposes.
soil conditions and environmental monitoring.
Anthropogenic interference significantly affects the number and
biomass of microorganisms and their distribution along the profile.
Microorganisms can be indicators of soil contamination by foreign
substances (heavy metals, oil products, etc.)

Soil microorganisms and human health.

Soil microorganisms and human health.
Actinomycetes are known as producers of antibiotics. The first antibiotics were
obtained from soil actinomycetes.
The soil is a habitat for a number of human pathogens
microorganisms.
Soil is a permanent habitat for botulism pathogens, and some
microorganisms (fungi, bacteria, actinomycetes) that form strong
toxins that are deadly to humans.
intestinal bacteria (E. coli,
pathogen
abdominal
typhoid,
salmonellosis,
dysentery)
may
get into the soil with faeces. Detection
these
microorganisms
V
soil
indicates contamination and
sanitary and epidemiological
trouble.
Distinguish
Also
microorganisms,
long lasting in the soil
which
she
is
secondary
reservoir.
So bacilli and clostridia are able to persist in the soil for a long time, forming spores.
(Anthrax). The causative agents of tetanus and gas gangrene are dangerous, living in
anaerobic conditions; Giardia and other protozoa that cause infection
organism.

Water as a habitat for microorganisms.

In all fresh and salt waters, as well as on land, there are representatives
different groups of microorganisms that take part in the nitrogen cycle,
carbon, phosphorus, iron, manganese, potassium and other elements.
The usual normal microflora of water is saprophytes, represented by
micrococci, sulfur and iron bacteria, mycelial and yeast-like
fungi, microscopic algae, protozoa, zooplankton, phages,
actinomycetes and other microorganisms.

The role of microorganisms in water bodies.

The Important Role of Microorganisms in Biological Productivity Processes
reservoirs is determined by the fact that microorganisms decompose dead
organic matter and mineralize its decay products. Besides,
the microorganisms themselves serve as food for aquatic animals.
The microbial population of water reflects the composition of the microflora of the soil, with which
water is in direct contact. Microorganisms that live in water
are common inhabitants of the soil. Microbes enter the water
not only from the soil, but also together with the secretions of humans, animals,
household waste, sewage, etc.

Factors affecting the microorganisms of water bodies.

The intensity of contamination of water by microorganisms and the composition of microflora
depends on many factors - on hydrochemical indicators, the season of the year,
the level of eutrophicity of the reservoir, water temperature, the degree of pollution
reservoir with waste, household and industrial waters, on the degree
pollution by organic and inorganic chemical compounds and
etc.
Near populated areas, the number of microorganisms in the water is especially high and
the species composition of microbes is more diverse.
For quantitative and qualitative
compound
microflora
open
bodies of water human activity
has a big impact. rivers and
other
open
ponds,
located within any
settlement, are subjected to
systematic
pollution
drains
economic
waters
And
fecal sewage
Microorganisms are indicators of hydrological phenomena in the seas,
oceans, freshwater and other bodies of water.

Water infection.

Pathogens can get into the water, persist and even multiply.
infectious diseases.
The waters of open reservoirs are polluted by pathogenic microbes in
as a result of ingestion of untreated Wastewater infectious and
veterinary clinics, farms, cowsheds, sewerage.
Cholera pathogens multiply in water and for a long time in water can
pathogens of dysentery, typhoid fever, enteroviruses,
leptospira, etc.

Microorganisms of the seas and oceans.

The water of the seas and oceans is also rich in microorganisms, but there are significantly more of them.
less than in freshwater open waters.
The bulk of the microbial population of the seas and oceans is concentrated in
coastal areas where settlements, as well as in areas
regular presence of ships.
Characteristic salt composition, low temperature, high pressure, small
concentrations of organic substances, sparseness of flora and fauna are
the main ecological features of the open areas of the seas and oceans for
vital activity of microorganisms.

Biochemical activity of microorganisms of the seas and oceans.
The vast majority of microorganisms living in the seas and oceans,
have significant biochemical activity.
Due to the activity of microbial enzymes, there is a transformation
carbohydrate substances. Many microorganisms use bound
oxygen nitrates, assimilate gaseous forms of nitrogen. Availability
bacteria that destroy organic matter, including chitin, to
simple compounds, causes the possibility of liberated nitrogen and
carbon to re-enter the cycle of matter. Influenced
vital activity of desulfurizing bacteria sulfates of sea water
turn into hydrogen sulfide.

Microorganisms

• Microorganisms, (microbes) - the name of a collective group of living organisms that are too small to be visible to the naked eye (their characteristic size is less than 0.1 mm). Microorganisms include both non-nuclear (prokaryotes: bacteria, archaea) and eukaryotes: some fungi, protists, but not viruses, which are usually isolated into a separate group. Most microorganisms consist of a single cell, but there are also multicellular microorganisms, just as there are some unicellular macroorganisms visible to the naked eye. Microbiology is the study of these organisms.

General information

• The ubiquity and total power of the metabolic potential of microorganisms determines their most important role in the circulation of substances and maintaining dynamic balance in the Earth's biosphere.
• Brief review various representatives microcosm, occupying certain "floors" of size, shows that, as a rule, the size of objects is definitely related to their structural complexity. The lower size limit for a free-living single-celled organism is determined by the space required to pack inside the cell the apparatus necessary for independent existence. The limit on the upper limit of the size of microorganisms is determined by modern ideas, relationships between cell surface and volume. With an increase in cellular dimensions, the surface increases in the square, and the volume in the cube, so the ratio between these values ​​shifts towards the latter.

Habitat

• Microorganisms live almost everywhere where there is water, including hot springs, the bottom of the world's oceans, and also deep inside the earth's crust. They are an important link in the metabolism in ecosystems, mainly acting as decomposers, but in some ecosystems they are the only producers of biomass. Microorganisms that live in water participate in the cycle of sulfur, iron and other elements, decompose organic matter of animal and vegetable origin, and provide self-purification of water in reservoirs. However, not all microorganisms benefit humans. Some microorganisms are opportunistic or pathogenic for humans and animals. Some microorganisms cause damage to agricultural products, lead to depletion of the soil with nitrogen, cause pollution of water bodies, and the accumulation of toxic substances (for example, microbial toxins). Microorganisms are characterized by good adaptability to the action of environmental factors. Various microorganisms can grow at temperatures from −6° to +50-75°. The record for survival at elevated temperatures was set by archaebacteria, which live at a temperature of about 300 °. This temperature is created by pressure in hot springs at the bottom of the ocean. There are microorganisms that exist at an increased level of ionizing radiation, at any pH value, at 25% sodium chloride concentration, under conditions of varying oxygen content up to its complete absence.
• At the same time, pathogenic microorganisms cause diseases in humans and animals and plants.
• The most widely accepted theories about the origin of life on Earth postulate that protomicroorganisms were the first living organisms to emerge through evolution.

• Thanks to the advances in biochemistry of microorganisms and especially the development genetics of microorganisms And molecular genetics It was found that many processes of biosynthesis and energy metabolism (electron transport, the tricarboxylic acid cycle, the synthesis of nucleic acids and proteins, etc.) proceed in microorganisms in the same way as in the cells of higher plants and animals. Thus, the growth, development, and reproduction of both higher and lower forms of life are based on the same processes. Along with this, microorganisms have specific enzyme systems and biochemical reactions that are not observed in other creatures. This is the basis for the ability of microorganisms to decompose cellulose, lignin, chitin, petroleum hydrocarbons, keratin, wax, etc. Microorganisms have extremely diverse ways of obtaining energy. Chemoautotrophs get it due to the oxidation of inorganic substances, photoautotrophic bacteria use light energy in that part of the spectrum that is inaccessible to higher plants, etc. Some microorganisms are able to assimilate molecular nitrogen (see. Nitrogen-fixing microorganisms ), synthesize protein from a variety of carbon sources, produce a variety of biologically active substances (antibiotics, enzymes, vitamins, growth stimulants, toxins, etc.). Application Microorganisms in page - x. practice and industry is based on these specific features of their metabolism.

• PATIENT MICROORGANISMS (pathogenic microorganisms), viruses, rickettsia, bacteria, microscopic pathogenic fungi, protozoa, causing various infectious diseases when they enter the human and animal body. Viruses cause influenza, measles, scarlet fever, poliomyelitis, hepatitis, AIDS, etc.; rickettsia- typhus. Among bacteria strepto- and staphylococci are the cause of purulent processes, sepsis (blood poisoning); meningococci infect the meninges; sticks - diphtheria, dysentery, tuberculosis, typhoid - the causative agents of the corresponding diseases. Pathogenic fungi cause a group of diseases called mycoses. Among the simplest pathogens are malarial Plasmodium, Giardia, Trichomonas, amoeba.

• The vital activity of microorganisms necessary condition the existence of an organic world on Earth. Thanks to the activity of microbes, the mineralization of organic residues is carried out, which ensures a continuous supply of carbon dioxide to the atmosphere, without which photosynthesis by plants is impossible. They take an active part in various geological processes. Weathering of rocks, formation of soils, formation of saltpeter, various ores (including sulfuric), limestone, oil, hard coal, peat - all these and many other processes occur with the direct participation of microorganisms.