In what processes are beneficial microorganisms involved? Beneficial and harmful human bacteria

The kingdom “Bacteria” consists of bacteria and blue-green algae, the general characteristic of which is their small size and the absence of a nucleus separated by a membrane from the cytoplasm.

Who are bacteria

Translated from Greek “bakterion” means stick. For the most part, microbes are single-celled organisms invisible to the naked eye that reproduce by division.

Who discovered them

For the first time, a Dutch researcher who lived in the 17th century, Anthony Van Leeuwenhoek, was able to see the smallest single-celled organisms in a homemade microscope. He began studying the world around him through a magnifying glass while working in a haberdashery store.

Anthony Van Leeuwenhoek (1632 - 1723)

Leeuwenhoek subsequently focused on making lenses capable of magnification up to 300 times. In them he examined the smallest microorganisms, describing the information received and transferring what he saw to paper.

In 1676, Leeuwenhoek discovered and presented information about microscopic creatures, to which he gave the name “animalcules.”

What do they eat?

The smallest microorganisms existed on Earth long before the appearance of humans. They have a ubiquitous distribution, feeding on organic food and inorganic substances.

Based on the methods of assimilation of nutrients, bacteria are usually divided into autotrophic and heterotrophic. For existence and development, heterotrophs use waste products from the organic decomposition of living organisms.

Representatives of bacteria

Biologists have identified about 2,500 groups of different bacteria.

According to their form they are divided into:

• cocci having spherical outlines;
• bacilli - rod-shaped;
• vibrios that have curves;
• spirilla – spiral shape;
• streptococci, consisting of chains;
• staphylococci that form grape-like clusters.

According to the degree of influence on the human body, prokaryotes can be divided into:

• useful;
• harmful.

Microbes dangerous to humans include staphylococci and streptococci, which cause purulent diseases.

The bacteria bifido and acidophilus are considered beneficial, stimulating the immune system and protecting the gastrointestinal tract.

How do real bacteria reproduce?

Reproduction of all types of prokaryotes occurs mainly by division, followed by growth to the original size. Having reached a certain size, an adult microorganism splits into two parts.

Less commonly, reproduction of similar unicellular organisms is performed by budding and conjugation. When budding on the mother microorganism, up to four new cells grow, followed by the death of the adult part.

Conjugation is considered the simplest sexual process in unicellular organisms. Most often, bacteria that live in animal organisms reproduce in this way.

Bacteria symbionts

Microorganisms involved in digestion in the human intestine are a prime example of symbiont bacteria. Symbiosis was first discovered by the Dutch microbiologist Martin Willem Beijerinck. In 1888, he proved the mutually beneficial close coexistence of unicellular and legume plants.

Living in the root system, symbionts, feeding on carbohydrates, supply the plant with atmospheric nitrogen. Thus, legumes increase fertility without depleting the soil.

There are many successful symbiotic examples involving bacteria and:

• person;
• algae;
• arthropods;
• sea ​​animals.

Microscopic single-celled organisms assist the systems of the human body, help purify wastewater, participate in the cycle of elements and work to achieve common goals.

Why are bacteria classified into a special kingdom?

These organisms are characterized by their small size, lack of a formed nucleus, and exceptional structure. Therefore, despite their external similarity, they cannot be classified as eukaryotes, which have a formed cell nucleus limited from the cytoplasm by a membrane.

Thanks to all their features, in the 20th century scientists identified them as a separate kingdom.

The most ancient bacteria

The smallest single-celled organisms are considered the first life to emerge on Earth. Researchers in 2016 discovered buried cyanobacteria in Greenland that were about 3.7 billion years old.

In Canada, traces of microorganisms that lived approximately 4 billion years ago in the ocean have been found.

Functions of bacteria

In biology, between living organisms and their environment, bacteria perform the following functions:

• processing of organic substances into minerals;
• nitrogen fixation.

In human life, single-celled microorganisms play an important role from the first minutes of birth. They provide a balanced intestinal microflora, influence the immune system, and maintain water-salt balance.

Bacterial reserve substance

In prokaryotes, reserve nutrients accumulate in the cytoplasm. They accumulate under favorable conditions and are consumed during periods of fasting.

Bacterial reserve substances include:

• polysaccharides;
• lipids;
• polypeptides;
• polyphosphates;
• sulfur deposits.

The main sign of bacteria

The function of the nucleus in prokaryotes is performed by the nucleoid.

Therefore, the main characteristic of bacteria is the concentration of hereditary material in one chromosome.

Why are representatives of the kingdom of bacteria classified as prokaryotes?

The absence of a formed nucleus was the reason for classifying bacteria as prokaryotic organisms.

How bacteria survive unfavorable conditions

Microscopic prokaryotes are able to endure unfavorable conditions for a long time, turning into spores. There is a loss of water from the cell, a significant decrease in volume and a change in shape.

Spores become insensitive to mechanical, temperature and chemical influences. In this way, the property of viability is preserved and effective resettlement is carried out.

Conclusion

Bacteria are the oldest form of life on Earth, known long before the appearance of humans. They are present everywhere: in the surrounding air, water, and in the surface layer of the earth’s crust. Habitats include plants, animals and humans.

Active study of single-celled organisms began in the 19th century and continues to this day. These organisms are a major part of people's daily lives and have a direct impact on human existence.

Margin of safety

Who lives in the intestines?

"Wise" neighbors

Permanent microflora

What are they doing?

Fickle microflora

Dislocation in the gastrointestinal tract

The role of bacteria in nature

Participation in food chains

Cyanobacteria

More than 2 kilograms of these microscopic creatures live in the human body! Moreover, most of them do not cause any harm, but live in peace and harmony with the owner of the body. But what are they for? What benefits and harm do bacteria bring to humans?

The role of bacteria living inside us

All microorganisms that inhabit a person from the inside can be divided into two categories:

1. Bacteria that bring tangible benefits to their owner. They help a person absorb and digest food, as well as synthesize beneficial vitamins. The most well-known bacterium with these properties is Escherichia coli. The intestinal microflora is also inhabited by various bacteroids, lacto- and bifidobacteria. Their benefit is to strengthen the immune system. They also reduce the risk of dangerous germs entering. Excessive use of antibiotics or other chemicals can kill beneficial bacteria. As a result, dysbiosis develops (diarrhea, constipation, nausea) and the human immune system suffers.
   • gonorrhea;
   • whooping cough;
   • diphtheria;
   • cholera;
   • plague and many other diseases.

When microbes enter the body of animals, they again cause great harm. They cause infection with diseases such as anthrax and brucellosis (and many others). Eating meat from an infected animal can cause serious harm to human health.

The importance of bacteria in various areas of life

There are many bacterial preparations that help fight pests in agriculture and forestry. Some of these microscopic creatures are used for ensiling green fodder. And to purify wastewater, a special type of bacteria is used, which decompose organic residues and help control the level of pollution in water bodies. And even in modern medicine, microorganisms are actively used to produce various vitamins, antibiotics and other medications.

Not all bacteria are beneficial and serve the benefit of people. There are also those that harm food, cause rotting of organic substances and produce poison. Eating low-quality food leads to poisoning of the body. In some cases, the result is completely sad - death. To protect yourself and your loved ones from harm caused by bad bacteria, as well as maintain the natural balance of beneficial creatures in the body, you need to:

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Beneficial and harmful bacteria. What bacteria are the most dangerous for humans?

Most people associate the word “bacteria” with something unpleasant and a threat to health. At best, fermented milk products come to mind. At worst - dysbacteriosis, plague, dysentery and other troubles. But bacteria are everywhere, they are good and bad. What can microorganisms hide?

What are bacteria

Bacteria means “stick” in Greek. This name does not mean that harmful bacteria are meant. They were given this name because of their shape. Most of these single cells look like rods. They also come in the form of triangles, squares, and star-shaped cells. For a billion years, bacteria do not change their appearance; they can only change internally. They can be movable or immobile. A bacterium consists of one cell. On the outside it is covered with a thin shell. This allows it to maintain its shape. There is no nucleus or chlorophyll inside the cell. There are ribosomes, vacuoles, cytoplasmic outgrowths, and protoplasm. The largest bacterium was found in 1999. It was called the “Grey Pearl of Namibia”. Bacteria and bacillus mean the same thing, they just have different origins.

Man and bacteria

In our body there is a constant battle between harmful and beneficial bacteria. Thanks to this process, a person receives protection from various infections. Various microorganisms surround us at every step. They live on clothes, fly in the air, they are omnipresent.

The presence of bacteria in the mouth, and this is about forty thousand microorganisms, protects the gums from bleeding, from periodontal disease and even from sore throat. If a woman’s microflora is disturbed, she may develop gynecological diseases. Following basic rules of personal hygiene will help avoid such failures.

Human immunity completely depends on the state of the microflora. Almost 60% of all bacteria are found in the gastrointestinal tract alone. The rest are located in the respiratory system and in the reproductive system. About two kilograms of bacteria live in a person.

The appearance of bacteria in the body

A newly born baby has a sterile intestine. After his first breath, many microorganisms enter the body with which he was previously unfamiliar. When the baby is first put to the breast, the mother transfers beneficial bacteria with milk, which will help normalize the intestinal microflora. It is not for nothing that doctors insist that the mother immediately after the birth of her child breastfeed him. They also recommend extending this feeding as long as possible.

Beneficial bacteria

Beneficial bacteria are: lactic acid bacteria, bifidobacteria, E. coli, streptomycents, mycorrhizae, cyanobacteria.

They all play an important role in human life. Some of them prevent the occurrence of infections, others are used in the production of medicines, and others maintain balance in the ecosystem of our planet.

Types of harmful bacteria

Harmful bacteria can cause a number of serious illnesses in humans. For example, diphtheria, anthrax, sore throat, plague and many others. They are easily transmitted from an infected person through air, food, or touch. It is the harmful bacteria, the names of which will be given below, that spoil food. They give off an unpleasant odor, rot and decompose, and cause diseases.

Bacteria can be gram-positive, gram-negative, rod-shaped.

Names of harmful bacteria

Table. Harmful bacteria for humans. Titles

Titles	Habitat	Harm
Mycobacteria	food, water	tuberculosis, leprosy, ulcer
Tetanus bacillus	soil, skin, digestive tract	tetanus, muscle spasms, respiratory failure
Plague stick (considered by experts as a biological weapon)	only in humans, rodents and mammals	bubonic plague, pneumonia, skin infections
Helicobacter pylori	human gastric mucosa	gastritis, peptic ulcer, produces cytoxins, ammonia
Anthrax bacillus	the soil	anthrax
Botulism stick	food, contaminated dishes	poisoning

Harmful bacteria can stay in the body for a long time and absorb beneficial substances from it. However, they can cause an infectious disease.

The most dangerous bacteria

One of the most resistant bacteria is methicillin. It is better known as Staphylococcus aureus (Staphylococcus aureus). This microorganism can cause not one, but several infectious diseases. Some types of these bacteria are resistant to powerful antibiotics and antiseptics. Strains of this bacterium can live in the upper respiratory tract, open wounds and urinary tract of every third inhabitant of the Earth. For a person with a strong immune system, this does not pose a danger.

Harmful bacteria to humans are also pathogens called Salmonella typhi. They are the causative agents of acute intestinal infections and typhoid fever. These types of bacteria, harmful to humans, are dangerous because they produce toxic substances that are extremely dangerous to life. As the disease progresses, intoxication of the body occurs, very high fever, rashes on the body, and the liver and spleen enlarge. The bacterium is very resistant to various external influences. Lives well in water, on vegetables, fruits and reproduces well in milk products.

Clostridium tetan is also one of the most dangerous bacteria. It produces a poison called tetanus exotoxin. People who become infected with this pathogen experience terrible pain, seizures and die very hard. The disease is called tetanus. Despite the fact that the vaccine was created back in 1890, 60 thousand people die from it every year on Earth.

And another bacterium that can lead to human death is Mycobacterium tuberculosis. It causes tuberculosis, which is drug-resistant. If you do not seek help in a timely manner, a person may die.

Measures to prevent the spread of infections

Harmful bacteria and the names of microorganisms are studied by doctors of all disciplines from their student days. Healthcare annually seeks new methods to prevent the spread of life-threatening infections. If you follow preventive measures, you will not have to waste energy on finding new ways to combat such diseases.

To do this, it is necessary to timely identify the source of the infection, determine the circle of sick people and possible victims. It is imperative to isolate those who are infected and disinfect the source of infection.

The second stage is the destruction of pathways through which harmful bacteria can be transmitted. For this purpose, appropriate propaganda is carried out among the population.

Food facilities, reservoirs, and food storage warehouses are taken under control.

Every person can resist harmful bacteria by strengthening their immunity in every possible way. A healthy lifestyle, observing basic hygiene rules, protecting yourself during sexual contact, using sterile disposable medical instruments and equipment, completely limiting communication with people in quarantine. If you enter an epidemiological area or a source of infection, you must strictly comply with all the requirements of sanitary and epidemiological services. A number of infections are equated in their effects to bacteriological weapons.

Bacteria are useful and harmful. Bacteria in human life

Bacteria are the most numerous inhabitants of planet Earth. They inhabited it in ancient times and continue to exist today. Some species have even changed little since then. Bacteria, beneficial and harmful, literally surround us everywhere (and even penetrate into other organisms). With a rather primitive unicellular structure, they are probably one of the most effective forms of living nature and are classified as a special kingdom.

Margin of safety

These microorganisms, as they say, do not drown in water and do not burn in fire. Literally: they can withstand temperatures up to plus 90 degrees, freezing, lack of oxygen, pressure – high and low. We can say that nature has invested a huge margin of safety in them.

Bacteria beneficial and harmful to the human body

As a rule, the bacteria that inhabit our bodies in abundance do not receive due attention. After all, they are so small that they seem to have no significant significance. Those who think so are largely mistaken. Beneficial and harmful bacteria have long and reliably “colonized” other organisms and successfully coexist with them. Yes, they cannot be seen without the help of optics, but they can benefit or harm our body.

Who lives in the intestines?

Doctors say that if you add together just the bacteria that live in the intestines and weigh them, you get something like three kilograms! Such a huge army cannot be ignored. Many microorganisms continuously enter the human intestine, but only some species find favorable conditions for living and living there. And in the process of evolution, they even formed a permanent microflora, which is designed to perform important physiological functions.

"Wise" neighbors

Bacteria have long played an important role in human life, although until very recently people had no idea about it. They help their owner with digestion and perform a number of other functions. What are these invisible neighbors?

Permanent microflora

99% of the population resides permanently in the intestines. They are ardent supporters and helpers of man.

• Essential beneficial bacteria. Names: bifidobacteria and bacteroides. They are the vast majority.
• Associated beneficial bacteria. Names: Escherichia coli, enterococci, lactobacilli. Their number should be 1-9% of the total.

You also need to know that under appropriate negative conditions, all these representatives of the intestinal flora (with the exception of bifidobacteria) can cause diseases.

What are they doing?

The main functions of these bacteria are to help us in the digestion process. It has been noted that dysbiosis can occur in a person with poor nutrition. The result is stagnation and poor health, constipation and other inconveniences. When a balanced diet is normalized, the disease usually recedes.

Another function of these bacteria is guard. They monitor which bacteria are beneficial. To ensure that “strangers” do not penetrate their community. If, for example, the causative agent of dysentery, Shigella Sonne, tries to penetrate the intestines, they kill it. However, it is worth noting that this only happens in the body of a relatively healthy person with good immunity. Otherwise, the risk of getting sick increases significantly.

Fickle microflora

Approximately 1% of the body of a healthy individual consists of so-called opportunistic microbes. They belong to the unstable microflora. Under normal conditions, they perform certain functions that do not harm humans and work for the benefit. But in certain situations they can manifest themselves as pests. These are mainly staphylococci and various types of fungi.

Dislocation in the gastrointestinal tract

In fact, the entire digestive tract has a heterogeneous and unstable microflora - beneficial and harmful bacteria. The esophagus contains the same inhabitants as in the oral cavity. In the stomach there are only a few that are acid-resistant: lactobacilli, Helicobacter, streptococci, fungi. The microflora in the small intestine is also sparse. Most bacteria are found in the colon. Thus, when defecating, a person is capable of excreting over 15 trillion microorganisms per day!

The role of bacteria in nature

It is also, of course, great. There are several global functions, without which all life on the planet would probably have ceased to exist long ago. The most important is sanitary. Bacteria eat dead organisms found in nature. They, in essence, work as a kind of wipers, preventing deposits of dead cells from accumulating. Scientifically they are called saprotrophs.

Another important role of bacteria is participation in the global cycle of substances on land and sea. On planet Earth, all substances in the biosphere pass from one organism to another. Without some bacteria, this transition would simply be impossible. The role of bacteria is invaluable, for example, in the circulation and reproduction of such an important element as nitrogen. There are certain bacteria in the soil that make nitrogenous fertilizers for plants from nitrogen in the air (microorganisms live right in their roots). This symbiosis between plants and bacteria is being studied by science.

Participation in food chains

As already mentioned, bacteria are the most numerous inhabitants of the biosphere. And accordingly, they can and should participate in food chains inherent in the nature of animals and plants. Of course, for humans, for example, bacteria are not a main part of the diet (unless they can be used as a food additive). However, there are organisms that feed on bacteria. These organisms, in turn, feed on other animals.

Cyanobacteria

These blue-green algae (an outdated name for these bacteria, fundamentally incorrect from a scientific point of view) are capable of producing huge amounts of oxygen through photosynthesis. Once upon a time, it was they who began to saturate our atmosphere with oxygen. Cyanobacteria continue to do this successfully to this day, producing a certain portion of the oxygen in the modern atmosphere!

Bacteria in nature are harmful and beneficial to humans

Most people view various bacterial organisms solely as harmful particles that can provoke the development of various pathological conditions. Nevertheless, according to scientists, the world of these organisms is very diverse. There are frankly dangerous bacteria that pose a danger to our body, but there are also useful ones - those that ensure the normal functioning of our organs and systems. Let's try to understand these concepts a little and consider individual types of such organisms. Let's talk about bacteria in nature that are harmful and beneficial to humans.

Beneficial bacteria

Scientists say that bacteria became the very first inhabitants of our big planet, and it is thanks to them that there is life on Earth now. Over the course of many millions of years, these organisms gradually adapted to the constantly changing conditions of existence, they changed their appearance and habitat. Bacteria were able to adapt to the surrounding space and were able to develop new and unique methods of life support, including multiple biochemical reactions - catalysis, photosynthesis and even seemingly simple respiration. Now bacteria coexist with human organisms, and such cooperation is characterized by some harmony, because such organisms are capable of bringing real benefits.

After a little person is born, bacteria immediately begin to penetrate into his body. They penetrate the respiratory tract along with the air, enter the body along with breast milk, etc. The entire body becomes saturated with various bacteria.

It is impossible to accurately calculate their number, but some scientists boldly say that the number of such cells in the body is comparable to the number of all cells. The digestive tract alone is home to four hundred different types of living bacteria. It is believed that a certain variety can grow only in a specific place. Thus, lactic acid bacteria are able to grow and multiply in the intestines, others feel optimal in the oral cavity, and some live only on the skin.

Over many years of coexistence, humans and such particles were able to recreate optimal conditions for cooperation for both groups, which can be characterized as a useful symbiosis. At the same time, bacteria and our body combine their capabilities, while each side remains in the black.

Bacteria are capable of collecting particles of various cells on their surface, which is why the immune system does not perceive them as hostile and does not attack them. However, after organs and systems are exposed to harmful viruses, beneficial bacteria rise to the defense and simply block the path of pathogens. When existing in the digestive tract, such substances also bring tangible benefits. They process leftover food, releasing a significant amount of heat. It, in turn, is transmitted to nearby organs, and is transferred throughout the body.

A deficiency of beneficial bacteria in the body or a change in their number causes the development of various pathological conditions. This situation can develop while taking antibiotics, which effectively destroy both harmful and beneficial bacteria. To correct the number of beneficial bacteria, special preparations - probiotics - can be consumed.

Harmful bacteria

However, it is worth remembering that not all bacteria are human friends. Among them there are also many dangerous varieties that can only cause harm. Such organisms, after entering our body, become the cause of the development of various bacterial ailments. These include various colds, some types of pneumonia, and also syphilis, tetanus and other diseases, even deadly ones. There are also diseases of this type that are transmitted by airborne droplets. This is dangerous tuberculosis, whooping cough, etc.

A significant number of ailments caused by harmful bacteria develop due to the consumption of insufficiently high-quality food, unwashed and unprocessed vegetables and fruits, raw water, and undercooked meat. You can protect yourself from such diseases by following the rules and regulations of hygiene. Examples of such dangerous illnesses are dysentery, typhoid fever, etc.

Manifestations of diseases that develop as a result of an attack by bacteria are the result of the pathological influence of poisons that these organisms produce or that are formed against the background of their destruction. The human body is able to get rid of them thanks to its natural defense, which is based on the process of phagocytosis of bacteria by white blood cells, as well as on the immune system, which synthesizes antibodies. The latter bind foreign proteins and carbohydrates, and then simply eliminate them from the bloodstream.

Also, harmful bacteria can be destroyed using natural and synthetic medications, the most famous of which is penicillin. All drugs of this type are antibiotics; they differ depending on the active component and the mode of action. Some of them are capable of destroying the cell membranes of bacteria, while others suspend their vital processes.

So, in nature there are a lot of bacteria that can bring benefits and harm to humans. Fortunately, the modern level of development of medicine makes it possible to cope with most pathological organisms of this kind.

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The benefits and harms of bacteria???

The fact is that bacteria bring not only harm, but also undoubted benefit. It is not for nothing that in the intestines of any organism there is a separate environment, which it would not hurt to separate into an independent organ, which is called the microflora of the body. Microflora includes a range of bacteria necessary for normal life.
The role of bacteria in human life is great. While still in the intestines, bacteria break down food residues indigestible in the stomach into organic and inorganic compounds. In the process, amino acids and some vitamins are extracted, which are immediately absorbed into the blood.
Bacteria are also found in dairy products - yoghurt, kefir, fermented baked milk. Together with these products, microorganisms enter the gastric tract, where they help the stomach itself cope with its main task - thoroughly digesting food. It is for this reason that we always feel light after eating dairy products and do not feel discomfort in the stomach caused by pain, colic or nausea.
The role of bacteria in human life is great. Being inside the female genital organs, microorganisms create a special acid-base environment, the violation of which leads to a number of unpleasant diseases and inflammations. To maintain such an optimal environment, personal hygiene must be observed.
The oral cavity is also full of microbes, which help get rid of inflammation and bleeding gums, tonsillitis and periodontal disease.
As you understand, microorganisms are located inside our entire body, and it’s not worth getting rid of them so violently. The role of bacteria in human life is ambiguous, but the fact that we need these simple organisms is one hundred percent correct answer.
Drink less antibiotics, which destroy the normal cooperation between microbes and humans, which leads to serious diseases.

Tanya

Benefit: Bacteria that bring tangible benefits to their owner. They help a person absorb and digest food, as well as synthesize beneficial vitamins. The most well-known bacterium with these properties is Escherichia coli. The intestinal microflora is also inhabited by various bacteroids, lacto- and bifidobacteria. Their benefit is to strengthen the immune system. They also reduce the risk of dangerous germs entering. Excessive use of antibiotics or other chemicals can kill beneficial bacteria. As a result, dysbiosis develops (diarrhea, constipation, nausea) and the human immune system suffers.

Sergey

Bacteria harmful to human health. Most often, pathogenic microbes enter the human body through airborne droplets. But this is far from the only way of infection. Dirty or stale food, bad water, poorly washed hands, various blood-sucking insects (fleas, lice, mosquitoes), a wound on the skin - all this can cause infection with bad microorganisms. Such organisms cause significant harm to health. Namely, they cause serious diseases:

What benefits and harm do bacteria bring to humans?

Elena

The harm from bacteria is very noticeable - many bacteria are sources of inflammation and infections. The deadly diseases typhoid and cholera, the serious diseases pneumonia and diphtheria are caused by bacteria, and it is not surprising that people are constantly looking for ways to combat them.
However, many bacteria are beneficial. Bacteria that cause, for example, fermentation of sweet juices or ripening of cream are beneficial. If bacteria did not decompose dead tissue, then the entire surface of the Earth would already be covered with it. But most importantly, bacteria participate in the formation of nitrates, which are necessary for plant life and, therefore, for our life.

Vladimir Kukuruzov

There are microorganisms that indirectly affect human life. They live in soils and water bodies and are involved in the breakdown of organic waste, ensure the rotting of dead plants, and saturate the soil with essential minerals and oxygen. Thanks to them, planet Earth does not lack oxygen.
Even in ancient times, people realized what invaluable benefits bacteria bring to humans in everyday life. Many food products cannot be produced without the use of beneficial bacteria. Fermented milk products (kefir, yogurt), acetic acid, confectionery products, cocoa, coffee are the result of the active activity of microorganisms. Even the production of tanned leather or, for example, flax fiber is not complete without their participation.
fermented milk products There are many bacterial preparations that help fight pests in agriculture and forestry. Some of these microscopic creatures are used for ensiling green fodder. And to purify wastewater, a special type of bacteria is used, which decompose organic residues and help control the level of pollution in water bodies. And even in modern medicine, microorganisms are actively used to produce various vitamins, antibiotics and other medications.
preparation with lactic acid bacteria Not all bacteria are beneficial and serve the benefit of people. There are also those that harm food, cause rotting of organic substances and produce poison. Eating low-quality food leads to poisoning of the body. In some cases, the result is completely sad - death. To protect yourself and your loved ones from harm caused by bad bacteria, as well as maintain the natural balance of beneficial creatures in the body, you need to:
Regularly eat fermented milk products enriched with bifidobacteria and lactobacilli.
Eat only fresh and high-quality foods.
Wash your hands before eating and thoroughly wash all fruits and vegetables.
Subject the meat to heat treatment.
Take antibiotics strictly as prescribed by your doctor. And try not to abuse various medications. Otherwise, instead of benefit, you can cause significant harm to your health.
Compliance with these simple rules is the key to a healthy life.

How do bacteria enter the human body and what harm do they cause?

ValyuSha

from the environment, for example, from dirty hands, towels, through the nose, mouth, skin, those who have normal immunity - bacteria are basically not scary, but those who have problems with it - due to bacteria, various illnesses can arise - colds, acne, diarrhea and so on.)

Dmitry Kalinkin

There is a hypothesis that all microorganisms are biorobots that perform the functions of repairing tissues, organs, cells, DNA
but not only repairs, but also, in general, changes in the internal state of living beings, people, animals and plants, as well as single-celled organisms. Viruses, like the smallest biorobots, engage in changes at the genetic level.
At the crudest level, helminths are used.
That is, all microorganisms are a tool for controlling the internal state of complex organisms from the control function of NATURE. There is even a humorous hypothesis that the driving force behind the evolution of living things is viruses, which forced all living things to develop in order to ensure the life of viruses. (After all, they cannot live on their own.

Grigory Miroshin

Eternity…………

The danger of bacterial diseases was greatly reduced at the end of the 19th century with the invention of vaccination, and in the middle of the 20th century with the discovery of antibiotics.

useful; For thousands of years, people have used lactic acid bacteria to produce cheese, yogurt, kefir, vinegar, and fermentation.

Currently, methods have been developed for the use of phytopathogenic bacteria as safe herbicides, and entomopathogenic bacteria instead of insecticides. The most widely used is Bacillus thuringiensis, which produces toxins (Cry-toxins) that affect insects. In addition to bacterial insecticides, bacterial fertilizers are used in agriculture.

Bacteria that cause human disease are used as biological weapons.

Due to their rapid growth and reproduction, as well as their simple structure, bacteria are actively used in scientific research in molecular biology, genetics, genetic engineering and biochemistry. The most well-studied bacterium is Escherichia coli. Information about bacterial metabolic processes has made it possible to produce bacterial synthesis of vitamins, hormones, enzymes, antibiotics, etc.

A promising direction is the enrichment of ores with the help of sulfur-oxidizing bacteria, the purification of soils and water bodies contaminated with petroleum products or xenobiotics by bacteria.

The human intestine normally contains from 300 to 1000 species of bacteria with a total mass of up to 1 kg, and the number of their cells is an order of magnitude greater than the number of cells in the human body. They play an important role in the digestion of carbohydrates, synthesize vitamins, and displace pathogenic bacteria. We can figuratively say that the human microflora is an additional “organ” that is responsible for protecting the body from infections and digestion.

It's not very short here. but I think you can shorten it as you like.

Karim Murotaliev

Bacteria and millennium man coexist with each other. They bring enormous benefits to humans. Beneficial bacteria make up 99% of the entire population that inhabit the human body and only 1% of them have a bad reputation. Because of the harm that bacteria cause to humans, any mention of them evokes negative emotions. Bacteria are found in the air we breathe, in the soil, in food and water, in plants, in our bodies, etc.

Rice. 1. Bacteria and humans.

The first bacteria on planet Earth appeared billions of years ago, long before the appearance of plants, animals and humans. For millions of years, changing their habitat in an unfavorable climate, they changed themselves, gradually improving their methods of life support, and over time populated the entire planet: oceans, soil, rocks, volcanoes and Arctic ice. The survival of bacteria was ensured by the presence of “jumping” genes, which they learned to pass on to each other along with the acquired achievements.

Rice. 2. Microbes are the real invisible masters of the Earth.

Rice. 3. About 70% of living creatures on Earth are bacteria.

Bacteria and humans: benefits for the human body

Bacteria have lived on planet Earth for more than 3.5 billion years. During this time they learned a lot and adapted to a lot. Now they help people. Bacteria and humans have become inseparable. As scientists have calculated, the human body contains from 500 to 1000 different types of bacteria or trillions of these amazing inhabitants, which amounts to up to 4 kg of total weight. Up to 3 kilograms of microbial bodies are found only in the intestines. The rest of them are found in the genitourinary tract, on the skin and other cavities of the human body.

The human body is inhabited by both beneficial and harmful bacteria. The existing balance between the human body and bacteria has been refined over centuries. When immunity decreases, “bad” bacteria cause great harm to the human body. Some diseases make it difficult to replenish the body with “good” bacteria.

Rice. 4. Bacteria inhabiting the oral cavity: Streptococcus mutants (green). Bakteroides gingivalis, causes periodontitis (lilac color). Candida albicus (yellow color).

Rice. 5. Inner surface of the colon. Pink islands are clusters of bacteria.

Rice. 6. Bacteria in the duodenum (indicated in red).

Rice. 7. Bacteria (blue and green) on human skin (computer image).

Microbes fill the body of a newborn from the first minutes of his life and finally form the composition of the intestinal microflora by the age of 10-13 years. The intestines are inhabited by streptococci, lactobacilli, bifidobacteria, enterobacteria, fungi, intestinal viruses, and non-pathogenic protozoa. Lactobacilli and bifidobacteria make up 60% of the intestinal flora. The composition of this group of bacteria is always constant, numerous and performs basic functions.

Rice. 12. Intestinal bacteria (red) in the duodenum.

The normal functioning of the human body is due to bifidobacteria, lactobacilli, enterococci, Escherichia coli and bacteriodes, which account for 99% of the normal intestinal microflora. 1% are representatives of opportunistic flora: clostridia, Pseudomonas aeruginosa, staphylococci, Proteus, etc.

Bifidobacteria

• Thanks to bifidobacteria, acetate and lactic acid are produced. By acidifying the environment, they suppress the growth of pathogenic bacteria that cause rotting and fermentation;
• thanks to bifidobacteria, the risk of developing food allergies in children is reduced;
• they provide antioxidant and antitumor effects;
• bifidobacteria take part in the synthesis of vitamin C;
• Bifidobacteria and lactobacilli take part in the processes of absorption of vitamin D, calcium and iron.

Rice. 13. Bifidobacteria. Three-dimensional image.

Escherichia coli

• Particular attention is paid to the representative of this genus Escherichia coli M17. It is capable of producing the substance cocilin, which inhibits the growth of a number of pathogenic microbes.
• With the participation of E. coli, vitamins K, group B (B1, B2, B5, B6, B7, B9 and B12), folic and nicotinic acids are synthesized.

Rice. 14. Escherichia coli. Three-dimensional image.

Rice. 15. Escherichia coli under a microscope.

Enterobacteriaceae

Enterobacteriaceae take an active part in the restoration of intestinal microflora after taking antibiotics.

Lactobacilli

Lactobacilli inhibit the growth of putrefactive and opportunistic microorganisms due to the formation of a number of antimicrobial substances.

Rice. 16. Lactobacilli (three-dimensional image).

Positive role of bacteria in the human body

• With the participation of bifido-, lacto- and enterobacteria, vitamins K, C, group B (B1, B2, B5, B6, B7, B9 and B12), folic and nicotinic acids are synthesized.
• Thanks to the intestinal microflora, undigested food components from the upper intestines are broken down - starch, cellulose, protein and fat fractions.
• Intestinal microflora maintains water-salt metabolism and ion homeostasis.
• Thanks to the secretion of special substances, the intestinal microflora suppresses the growth of pathogenic bacteria that cause rotting and fermentation.
• Bifido-, lacto- and enterobacteria take part in the detoxification of substances that enter from the outside and are formed inside the body itself.
• Intestinal microflora plays a big role in restoring local immunity. Thanks to it, the number of lymphocytes, the activity of phagocytes and the production of immunoglobulin A increase.
• Thanks to the intestinal microflora, the development of the lymphoid apparatus is stimulated.
• Increases the resistance of the intestinal epithelium to carcinogens.
• Microflora protect the intestinal mucosa and provide energy to the intestinal epithelium.
• Regulates intestinal motility.
• The intestinal flora acquires the skills to capture and remove viruses from the host’s body, with which it has been in symbiosis for many years.
• Maintains the body's thermal balance. The microflora is nourished by substances that are not digested by the enzymatic system and come from the upper parts of the gastrointestinal tract. As a result of complex biochemical reactions, a huge amount of thermal energy is produced. Heat is carried through the bloodstream throughout the body and enters all internal organs. This is why a person always freezes when fasting.
• Regulates the reabsorption of bile acid components (cholesterol), hormones, etc.

Rice. 17. Lactobacillus and Bifidobacterium bifidum cells.

Rice. 18. Escherichia coli.

In diseases that reduce the body's immunity, intestinal diseases, long-term use of antibacterial drugs and in the absence of lactose in the human body, when the sugar contained in milk is not digested and begins to ferment in the intestines, changing the acid balance of the intestines, a microbial imbalance occurs - dysbiosis (dysbiosis). Dysbacteriosis is characterized by the death of “good” bacteria and increased growth of pathogenic microorganisms and fungi. The processes of rotting and fermentation begin to prevail in the intestines. This is manifested by diarrhea and bloating, pain, loss of appetite, and then weight, children begin to lag behind in development, anemia and hypovitaminosis develop.

Bacteria and humans will always coexist together. The health of every person is in his hands. If a person takes care of himself, he will remain healthy, and therefore happy, for many years.

Rice. 19. Bacteria and humans. Together forever.

Most people associate the word “bacteria” with something unpleasant and a threat to health. At best, fermented milk products come to mind. At worst - dysbacteriosis, plague, dysentery and other troubles. But bacteria are everywhere, they are good and bad. What can microorganisms hide?

What are bacteria

Bacteria means “stick” in Greek. This name does not mean that harmful bacteria are meant. They were given this name because of their shape. Most of these single cells look like rods. They also come in the form of triangles, squares, and star-shaped cells. For a billion years, bacteria do not change their appearance; they can only change internally. They can be movable or immobile. A bacterium consists of one cell. On the outside it is covered with a thin shell. This allows it to maintain its shape. There is no nucleus or chlorophyll inside the cell. There are ribosomes, vacuoles, cytoplasmic outgrowths, and protoplasm. The largest bacterium was found in 1999. It was called the "Grey Pearl of Namibia". Bacteria and bacillus mean the same thing, they just have different origins.

Man and bacteria

In our body there is a constant battle between harmful and beneficial bacteria. Thanks to this process, a person receives protection from various infections. Various microorganisms surround us at every step. They live on clothes, fly in the air, they are omnipresent.

The presence of bacteria in the mouth, and this is about forty thousand microorganisms, protects the gums from bleeding, from periodontal disease and even from sore throat. If a woman’s microflora is disturbed, she may develop gynecological diseases. Following basic rules of personal hygiene will help avoid such failures.

Human immunity completely depends on the state of the microflora. Almost 60% of all bacteria are found in the gastrointestinal tract alone. The rest are located in the respiratory system and in the reproductive system. About two kilograms of bacteria live in a person.

The appearance of bacteria in the body

A newly born baby has a sterile intestine.
After his first breath, many microorganisms enter the body with which he was previously unfamiliar. When the baby is first put to the breast, the mother transfers beneficial bacteria with milk, which will help normalize the intestinal microflora. It is not for nothing that doctors insist that the mother immediately after the birth of her child breastfeed him. They also recommend extending this feeding as long as possible.

Beneficial bacteria

Beneficial bacteria are: lactic acid bacteria, bifidobacteria, E. coli, streptomycents, mycorrhizae, cyanobacteria.

They all play an important role in human life. Some of them prevent the occurrence of infections, others are used in the production of medicines, and others maintain balance in the ecosystem of our planet.

Types of harmful bacteria

Harmful bacteria can cause a number of serious illnesses in humans. For example, diphtheria, anthrax, sore throat, plague and many others. They are easily transmitted from an infected person through air, food, or touch. It is the harmful bacteria, the names of which will be given below, that spoil food. They give off an unpleasant odor, rot and decompose, and cause diseases.

Bacteria can be gram-positive, gram-negative, rod-shaped.

Names of harmful bacteria

Table. Harmful bacteria for humans. Titles

Titles	Habitat	Harm
Mycobacteria	food, water	tuberculosis, leprosy, ulcer
Tetanus bacillus	soil, skin, digestive tract	tetanus, muscle spasms, respiratory failure
Plague stick (considered by experts as a biological weapon)	only in humans, rodents and mammals	bubonic plague, pneumonia, skin infections
Helicobacter pylori	human gastric mucosa	gastritis, peptic ulcer, produces cytoxins, ammonia
Anthrax bacillus	the soil	anthrax
Botulism stick	food, contaminated dishes	poisoning

Harmful bacteria can stay in the body for a long time and absorb beneficial substances from it. However, they can cause an infectious disease.

The most dangerous bacteria

One of the most resistant bacteria is methicillin. It is better known as Staphylococcus aureus (Staphylococcus aureus). This microorganism can cause not one, but several infectious diseases. Some types of these bacteria are resistant to powerful antibiotics and antiseptics. Strains of this bacterium can live in the upper respiratory tract, open wounds and urinary tract of every third inhabitant of the Earth. For a person with a strong immune system, this does not pose a danger.

Harmful bacteria to humans are also pathogens called Salmonella typhi. They are the causative agents of acute intestinal infections and typhoid fever. These types of bacteria, harmful to humans, are dangerous because they produce toxic substances that are extremely dangerous to life. As the disease progresses, intoxication of the body occurs, very high fever, rashes on the body, and the liver and spleen enlarge. The bacterium is very resistant to various external influences. Lives well in water, on vegetables, fruits and reproduces well in milk products.

Clostridium tetan is also one of the most dangerous bacteria. It produces a poison called tetanus exotoxin. People who become infected with this pathogen experience terrible pain, seizures and die very hard. The disease is called tetanus. Despite the fact that the vaccine was created back in 1890, 60 thousand people die from it every year on Earth.

And another bacterium that can lead to human death is Mycobacterium tuberculosis. It causes tuberculosis, which is drug-resistant. If you do not seek help in a timely manner, a person may die.

Measures to prevent the spread of infections

Harmful bacteria and the names of microorganisms are studied by doctors of all disciplines from their student days. Healthcare annually seeks new methods to prevent the spread of life-threatening infections. If you follow preventive measures, you will not have to waste energy on finding new ways to combat such diseases.

To do this, it is necessary to timely identify the source of the infection, determine the circle of sick people and possible victims. It is imperative to isolate those who are infected and disinfect the source of infection.

The second stage is the destruction of pathways through which harmful bacteria can be transmitted. For this purpose, appropriate propaganda is carried out among the population.

Food facilities, reservoirs, and food storage warehouses are taken under control.

Every person can resist harmful bacteria by strengthening their immunity in every possible way. A healthy lifestyle, observing basic hygiene rules, protecting yourself during sexual contact, using sterile disposable medical instruments and equipment, completely limiting communication with people in quarantine. If you enter an epidemiological area or a source of infection, you must strictly comply with all the requirements of sanitary and epidemiological services. A number of infections are equated in their effects to bacteriological weapons.

Most people view various bacterial organisms solely as harmful particles that can provoke the development of various pathological conditions. Nevertheless, according to scientists, the world of these organisms is very diverse. There are frankly dangerous bacteria that pose a danger to our body, but there are also useful ones - those that ensure the normal functioning of our organs and systems. Let's try to understand these concepts a little and consider individual types of such organisms. Let's talk about bacteria in nature that are harmful and beneficial to humans.

Beneficial bacteria

Scientists say that bacteria became the very first inhabitants of our big planet, and it is thanks to them that there is life on Earth now. Over the course of many millions of years, these organisms gradually adapted to the constantly changing conditions of existence, they changed their appearance and habitat. Bacteria were able to adapt to the surrounding space and were able to develop new and unique methods of life support, including multiple biochemical reactions - catalysis, photosynthesis and even seemingly simple respiration. Now bacteria coexist with human organisms, and such cooperation is characterized by some harmony, because such organisms are capable of bringing real benefits.

After a little person is born, bacteria immediately begin to penetrate into his body. They penetrate the respiratory tract along with the air, enter the body along with breast milk, etc. The entire body becomes saturated with various bacteria.

It is impossible to accurately calculate their number, but some scientists boldly say that the number of such cells in the body is comparable to the number of all cells. The digestive tract alone is home to four hundred different types of living bacteria. It is believed that a certain variety can grow only in a specific place. Thus, lactic acid bacteria are able to grow and multiply in the intestines, others feel optimal in the oral cavity, and some live only on the skin.

Over many years of coexistence, humans and such particles were able to recreate optimal conditions for cooperation for both groups, which can be characterized as a useful symbiosis. At the same time, bacteria and our body combine their capabilities, while each side remains in the black.

Bacteria are capable of collecting particles of various cells on their surface, which is why the immune system does not perceive them as hostile and does not attack them. However, after organs and systems are exposed to harmful viruses, beneficial bacteria rise to the defense and simply block the path of pathogens. When existing in the digestive tract, such substances also bring tangible benefits. They process leftover food, releasing a significant amount of heat. It, in turn, is transmitted to nearby organs, and is transferred throughout the body.

A deficiency of beneficial bacteria in the body or a change in their number causes the development of various pathological conditions. This situation can develop while taking antibiotics, which effectively destroy both harmful and beneficial bacteria. To correct the number of beneficial bacteria, special preparations - probiotics - can be consumed.

Harmful bacteria

However, it is worth remembering that not all bacteria are human friends. Among them there are also many dangerous varieties that can only cause harm. Such organisms, after entering our body, become the cause of the development of various bacterial ailments. These include various colds, some types of pneumonia, and also syphilis, tetanus and other diseases, even deadly ones. There are also diseases of this type that are transmitted by airborne droplets. This is dangerous tuberculosis, whooping cough, etc.

A significant number of ailments caused by harmful bacteria develop due to the consumption of insufficiently high-quality food, unwashed and unprocessed vegetables and fruits, raw water, and undercooked meat. You can protect yourself from such diseases by following the rules and regulations of hygiene. Examples of such dangerous illnesses are dysentery, typhoid fever, etc.

Manifestations of diseases that develop as a result of an attack by bacteria are the result of the pathological influence of poisons that these organisms produce or that are formed against the background of their destruction. The human body is able to get rid of them thanks to its natural defense, which is based on the process of phagocytosis of bacteria by white blood cells, as well as on the immune system, which synthesizes antibodies. The latter bind foreign proteins and carbohydrates, and then simply eliminate them from the bloodstream.

Also, harmful bacteria can be destroyed using natural and synthetic medications, the most famous of which is penicillin. All drugs of this type are antibiotics; they differ depending on the active component and the mode of action. Some of them are capable of destroying the cell membranes of bacteria, while others suspend their vital processes.

So, in nature there are a lot of bacteria that can bring benefits and harm to humans. Fortunately, the modern level of development of medicine makes it possible to cope with most pathological organisms of this kind.

Help me, I need a brief description of beneficial and harmful bacteria, all of them are not covered, they are not missing, please help me

Eternity............

The danger of bacterial diseases was greatly reduced at the end of the 19th century with the invention of vaccination, and in the middle of the 20th century with the discovery of antibiotics.

Useful; For thousands of years, people have used lactic acid bacteria to produce cheese, yogurt, kefir, vinegar, and fermentation.

Currently, methods have been developed for the use of phytopathogenic bacteria as safe herbicides, and entomopathogenic bacteria instead of insecticides. The most widely used is Bacillus thuringiensis, which produces toxins (Cry-toxins) that affect insects. In addition to bacterial insecticides, bacterial fertilizers are used in agriculture.

Bacteria that cause human disease are used as biological weapons.

Due to their rapid growth and reproduction, as well as their simple structure, bacteria are actively used in scientific research in molecular biology, genetics, genetic engineering and biochemistry. The most well-studied bacterium is Escherichia coli. Information about bacterial metabolic processes has made it possible to produce bacterial synthesis of vitamins, hormones, enzymes, antibiotics, etc.

A promising direction is the enrichment of ores with the help of sulfur-oxidizing bacteria, the purification of soils and water bodies contaminated with petroleum products or xenobiotics by bacteria.

The human intestine normally contains from 300 to 1000 species of bacteria with a total mass of up to 1 kg, and the number of their cells is an order of magnitude greater than the number of cells in the human body. They play an important role in the digestion of carbohydrates, synthesize vitamins, and displace pathogenic bacteria. We can figuratively say that the human microflora is an additional “organ” that is responsible for protecting the body from infections and digestion.

It's not entirely short. but I think you can shorten it as you like.

Bacteria- one of the most ancient organisms on Earth. Despite the simplicity of their structure, they live in all possible habitats. Most of them are found in the soil (up to several billion bacterial cells per 1 gram of soil). There are many bacteria in the air, water, food, inside and on the bodies of living organisms. Bacteria have been found in places where other organisms cannot live (on glaciers, in volcanoes).

Typically a bacterium is a single cell (although there are colonial forms). Moreover, this cell is very small (from fractions of a micron to several tens of microns). But the main feature of a bacterial cell is the absence of a cell nucleus. In other words, bacteria belong prokaryotes.

Bacteria are either mobile or immobile. In the case of non-motile forms, movement is carried out using flagella. There may be several of them, or there may be only one.

Cells of different types of bacteria can differ greatly in shape. There are spherical bacteria ( cocci), rod-shaped ( bacilli), similar to a comma ( vibrios), crimped ( spirochetes, spirilla) and etc.

Structure of a bacterial cell

Many bacterial cells have mucous capsule. It performs a protective function. In particular, it protects the cell from drying out.

Like plant cells, bacterial cells have cell wall. However, unlike plants, its structure and chemical composition are somewhat different. The cell wall is made up of layers of complex carbohydrates. Its structure is such that it allows various substances to penetrate into the cell.

Under the cell wall is cytoplasmic membranenA.

Bacteria are classified as prokaryotes because their cells do not have a formed nucleus. They do not have the chromosomes characteristic of eukaryotic cells. The chromosome contains not only DNA, but also protein. In bacteria, their chromosome consists only of DNA and is a circular molecule. This genetic apparatus of bacteria is called nucleoid. The nucleoid is located directly in the cytoplasm, usually in the center of the cell.

Bacteria do not have true mitochondria and a number of other cellular organelles (Golgi complex, endoplasmic reticulum). Their functions are performed by invaginations of the cell cytoplasmic membrane. Such invaginations are called mesosomes.

In the cytoplasm there is ribosomes, as well as various organic inclusion: proteins, carbohydrates (glycogen), fats. Bacterial cells may also contain various pigments. Depending on the presence or absence of certain pigments, bacteria can be colorless, green, or purple.

Nutrition of bacteria

Bacteria arose at the dawn of life on Earth. They were the ones who “discovered” different ways of eating. Only later, with the complication of organisms, two large kingdoms clearly emerged: Plants and Animals. They differ from each other primarily in the way they feed. Plants are autotrophs, and animals are heterotrophs. Bacteria have both types of nutrition.

Nutrition is the way a cell or body obtains the necessary organic substances. They can be obtained from outside or synthesized independently from inorganic substances.

Autotrophic bacteria

Autotrophic bacteria synthesize organic substances from inorganic ones. The synthesis process requires energy. Depending on where autotrophic bacteria receive this energy from, they are divided into photosynthetic and chemosynthetic.

Photosynthetic bacteria use the energy of the Sun, capturing its radiation. In this they are similar to plants. However, while plants release oxygen during photosynthesis, most photosynthetic bacteria do not release it. That is, bacterial photosynthesis is anaerobic. Also, the green pigment of bacteria differs from the similar pigment of plants and is called bacteriochlorophyll. Bacteria do not have chloroplasts. Mostly photosynthetic bacteria live in bodies of water (fresh and salty).

Chemosynthetic bacteria To synthesize organic substances from inorganic ones, the energy of various chemical reactions is used. Energy is not released in all reactions, but only in exothermic ones. Some of these reactions take place in bacterial cells. So in nitrifying bacteria the oxidation of ammonia into nitrites and nitrates occurs. Iron bacteria oxidize ferrous iron into oxide iron. Hydrogen bacteria oxidize hydrogen molecules.

Heterotrophic bacteria

Heterotrophic bacteria are not capable of synthesizing organic substances from inorganic ones. Therefore, we are forced to obtain them from the environment.

Bacteria that feed on the organic remains of other organisms (including dead bodies) are called saprophyte bacteria. They are otherwise called rotting bacteria. There are many such bacteria in the soil, where they decompose humus into inorganic substances, which are subsequently used by plants. Lactic acid bacteria feed on sugars, converting them into lactic acid. Butyric acid bacteria decompose organic acids, carbohydrates, and alcohols to butyric acid.

Nodule bacteria live in the roots of plants and feed on the organic matter of the living plant. However, they fix nitrogen from the air and provide it to the plant. That is, in this case there is a symbiosis. Other heterotrophic symbiont bacteria live in the digestive system of animals, helping to digest food.

During the process of respiration, organic substances are destroyed and energy is released. This energy is subsequently spent on various vital processes (for example, movement).

An effective way to obtain energy is oxygen respiration. However, some bacteria can obtain energy without oxygen. Thus, there are aerobic and anaerobic bacteria.

Aerobic bacteria oxygen is needed, so they live in places where it is available. Oxygen is involved in the oxidation reaction of organic substances to carbon dioxide and water. In the process of such respiration, bacteria receive a relatively large amount of energy. This method of breathing is characteristic of the vast majority of organisms.

Anaerobic bacteria They do not need oxygen to breathe, so they can live in an oxygen-free environment. They receive energy from fermentation reactions. This oxidation method is ineffective.

Bacteria reproduction

In most cases, bacteria reproduce by dividing their cells in two. Before this, the circular DNA molecule doubles. Each daughter cell receives one of these molecules and is therefore a genetic copy of the mother cell (clone). Thus, it is typical for bacteria asexual reproduction.

Under favorable conditions (with sufficient nutrients and favorable environmental conditions), bacterial cells divide very quickly. So from one bacterium hundreds of millions of cells can form per day.

Although bacteria reproduce asexually, in some cases they exhibit the so-called sexual process, which flows in the form conjugation. During conjugation, two different bacterial cells come closer and a connection is established between their cytoplasms. Parts of the DNA of one cell are transferred to the second, and parts of the DNA of the second cell are transferred to the first. Thus, during the sexual process, bacteria exchange genetic information. Sometimes bacteria exchange not sections of DNA, but entire DNA molecules.

Bacterial spores

The vast majority of bacteria form spores under unfavorable conditions. Bacterial spores are mainly a way of surviving unfavorable conditions and a method of dispersal, rather than a method of reproduction.

When a spore is formed, the cytoplasm of the bacterial cell contracts, and the cell itself is covered with a dense, thick protective membrane.

Bacterial spores remain viable for a long time and are able to survive very unfavorable conditions (extremely high and low temperatures, drying out).

When a spore finds itself in favorable conditions, it swells. After this, the protective shell is shed, and an ordinary bacterial cell appears. It happens that cell division occurs and several bacteria are formed. That is, sporulation is combined with reproduction.

The importance of bacteria

The role of bacteria in the cycle of substances in nature is enormous. This primarily applies to rotting bacteria (saprophytes). They are called nature's orderlies. By decomposing the remains of plants and animals, bacteria convert complex organic substances into simple inorganic substances (carbon dioxide, water, ammonia, hydrogen sulfide).

Bacteria increase soil fertility by enriching it with nitrogen. Nitrifying bacteria undergo reactions during which nitrites are formed from ammonia, and nitrates from nitrites. Nodule bacteria are able to assimilate atmospheric nitrogen, synthesizing nitrogen compounds. They live in the roots of plants, forming nodules. Thanks to these bacteria, plants receive the nitrogen compounds they need. Basically, leguminous plants enter into symbiosis with nodule bacteria. After they die, the soil is enriched with nitrogen. This is often used in agriculture.

In the stomach of ruminants, bacteria break down cellulose, which promotes more efficient digestion.

The positive role of bacteria in the food industry is great. Many types of bacteria are used to produce lactic acid products, butter and cheese, pickling vegetables, and also in winemaking.

In the chemical industry, bacteria are used to produce alcohols, acetone, and acetic acid.

In medicine, bacteria are used to produce a number of antibiotics, enzymes, hormones and vitamins.

However, bacteria can also cause harm. They not only spoil food, but with their secretions they make it poisonous.

The beneficial bacteria that inhabit the human body are called microbiota. They are quite vast in number - one person has millions of them. Moreover, they all regulate the health and normal functioning of each individual. Scientists say: without beneficial bacteria, or, as they are also called, mutualists, the gastrointestinal tract, skin, and respiratory tract would instantly be attacked by pathogenic microbes and would be destroyed.

What should be the balance of microbiota in the body and how it can be adjusted to avoid the development of serious diseases, AiF.ru asked General Director of the biomedical holding Sergei Musienko.

Intestinal Workers

One of the important areas where beneficial bacteria are located is the intestines. It is not without reason that it is believed that this is where the entire human immune system is founded. And if the bacterial environment is disturbed, then the body’s defenses are significantly reduced.

Beneficial intestinal bacteria create literally unbearable living conditions for pathogenic microbes - an acidic environment. In addition, beneficial microorganisms help digest plant foods, since bacteria feed on plant cells containing cellulose, but intestinal enzymes cannot cope with this alone. Also, intestinal bacteria contribute to the production of vitamins B and K, which ensure metabolism in bones and connective tissues, as well as release energy from carbohydrates and promote the synthesis of antibodies and regulation of the nervous system.

Most often, when talking about beneficial intestinal bacteria, they mean the 2 most popular types: bifidobacteria and lactobacilli. At the same time, they cannot be called the main ones, as many people think - their number is only 5-15% of the total. However, they are very important, since their positive effect on other bacteria has been proven, when such bacteria can be important factors in the well-being of an entire community: if they are fed or introduced into the body with fermented milk products - kefirs or yoghurts, they help other important bacteria to survive and reproduce . For example, it is very important to restore their population during dysbacteriosis or after a course of antibiotics. Otherwise, it will be problematic to increase the body’s defenses.

Biological shield

The bacteria that inhabit the skin and respiratory tract of humans, in fact, stand guard and reliably protect their area of ​​​​responsibility from the penetration of pathogenic organisms. The main ones are micrococci, streptococci and staphylococci.

The skin microbiome has undergone changes over the past hundreds of years, as humans have moved from a natural life in contact with nature to regular washing with special products. It is believed that human skin is now inhabited by completely different bacteria that lived before. The body, with the help of the immune system, can distinguish dangerous from non-dangerous. But, on the other hand, any streptococcus can become pathogenic for a person, for example, if it gets into a cut or any other open wound on the skin. An excess of bacteria or their pathological activity on the skin and in the respiratory tract can lead to the development of various diseases and the appearance of an unpleasant odor. Today there are developments based on bacteria that oxidize ammonium. Their use makes it possible to seed the skin microbiome with completely new organisms, as a result of which not only the smell disappears (the result of the metabolism of urban flora), but also the structure of the skin changes - pores open, etc.

Saving the microworld

The microcosm of each person changes quite quickly. And this has undoubted advantages, since the number of bacteria can be updated independently.

Different bacteria feed on different substances - the more varied a person’s food is and the more it matches the season, the more choice beneficial microorganisms have. However, if food is heavily loaded with antibiotics or preservatives, bacteria will not survive, because these substances are precisely designed to destroy them. Moreover, it does not matter at all that most of the bacteria are not pathogenic. As a result, the diversity of a person’s inner world is destroyed. And after this, various diseases begin - problems with stool, skin rashes, metabolic disorders, allergic reactions, etc.

But the microbiota can be helped. Moreover, it will take only a few days for a slight correction.

There are a large number of probiotics (with live bacteria) and prebiotics (substances that support bacteria). But the main problem is that they work differently for everyone. Analysis shows that their effectiveness against dysbacteriosis is up to 70-80%, that is, one or another drug may work, or it may not. And here you should carefully monitor the progress of treatment and administration - if the remedies work, you will immediately notice improvements. If the situation remains unchanged, it is worth changing the treatment program.

Alternatively, you can undergo special testing that studies the genomes of bacteria, determines their composition and ratio. This allows you to quickly and competently select the necessary nutritional option and additional therapy, which will restore the fragile balance. Although a person does not feel slight disturbances in the balance of bacteria, they still affect health - in this case, frequent illnesses, drowsiness, and allergic manifestations can be noted. Every city resident, to one degree or another, has an imbalance in the body, and if he does not do anything specifically to restore it, then he will probably have health problems from a certain age.

Fasting, fasting, more vegetables, porridge from natural cereals in the morning - these are just a few options for eating behavior that beneficial bacteria love. But for each person, the diet should be individual in accordance with the state of his body and his lifestyle - only then can he maintain an optimal balance and always feel good.