Where can bacteria live? Bacteria habitat

Microscopic living organisms, the smallest on the planet, the most numerous inhabitants of the Earth are bacteria. These are creatures, at least, amazing, interesting sciences since when, with the invention of the multiple magnification of objects (a microscope), they were finally noticed by mankind. Before that, the evolution of bacteria passed through people, one might say, "under the very nose", but no one paid due attention to them. And completely in vain!

Antiquity of origin

They are the oldest inhabitants of our planet. The long-term habitat of bacteria is Earth. Bacteria appeared here as the first of living organisms, according to some scientists, about three and a half billion years ago (for comparison: the age of the Earth is about four billion). That is, roughly speaking, the age of bacteria is comparable to the age of the surrounding nature. By the way, the known history of mankind totals only a few tens of thousands of years. Here we are "young" in comparison with these microorganisms.

The smallest and most numerous

Bacteria are also the smallest of all known representatives of wildlife. The fact is that cells of almost all living organisms have approximately the same size. But not bacteria cells. The average bacterial cell is about ten times smaller in size than the average cell, for example, a human. Because of this tiny, they are also the most numerous inhabitants. It is known that in a lump of soil where bacteria live, there can be as many inhabitants as, for example, people in all countries of Europe.

Endurance

Nature, creating bacteria, has invested in them a huge safety margin, far exceeding the endurance of other fauna. Since the "ancient times of the deep", many cataclysms have occurred on the Earth, and the bacteria have learned to persevere with them. And today the habitat of bacteria is so diverse that it causes a deep interest of microbiologists. Microorganisms can sometimes be found in places where it is certain that none of the other creatures can live.

Where can bacteria live?

For example, in boiling geysers, where the water temperature can reach almost one hundred degrees above zero. Or - in oil underground lakes, as well as in acid lakes that are unsuitable for life, where any fish or other animal would immediately dissolve - that's where bacteria can live.

Scientists suggest that some types of bacteria can exist even in space! By the way, this data is based on one of the versions of the settling of the globe by living beings, the theory of the origin of life on the planet.

Disputes

In order to tolerate such unfavorable conditions, some bacteria form spores. We can say that this is a special, sleeping, resting form. Before forming a spore, the bacterium begins to dry up, removing the fluid from itself. It decreases in size, remaining inside its shell, being covered additionally with one more shell - of a protective nature. In this form, the microorganism can exist very, very long, thus, as if "waiting" for difficult times. Then, depending on the environment in which the bacteria live - whether favorable or not - they can resume their vital activity in full. This unique ability to survive in adverse conditions is carefully studied by microbiologists.

Ubiquitous

The question "where do bacteria live?" Can be answered very simply: "Almost everywhere!" Namely: around us and in us, in the atmosphere, in the soil, in the water. And each person daily comes into contact with the myriad of these beings, without noticing it. Among them there are bacteria pathogenic and conditionally pathogenic. There are absolutely safe for the human body.

On the ground

In the soil where bacteria live, they contain the greatest number. Here there are nutrients necessary for life, and the optimum amount of water, there is no direct sunlight. Most of these bacteria are saprophytes. They participate in the formation of the fertile part of the soil (humus). However, there are also pathogenic microorganisms: pathogens of tetanus, botulism, gas gangrene and other diseases. Then they can get into the air and water, further infecting people with these diseases.

So, the causative agent of tetanus, a rather large stick, gets into the body from the soil with various damages to the skin and multiplies in anaerobic (without oxygen) conditions.

In water

Even where bacteria can live, it's in the water. Here they fall when they are washed from the soil, and the effluents fall into the reservoirs. For this reason, by the way, in artesian water there are much fewer bacteria than in the above-ground water. Ordinary water from a lake or a river can become an environment where pathogenic bacteria live, a place where many dangerous diseases spread: typhoid fever, cholera, dysentery and some others. For example, dysentery is caused by bacteria from Shigella species and is accompanied by severe intoxication of the body, lesions of the gastrointestinal tract.

In the atmosphere

In the air, where bacteria can live, there are not so many of them as in the soil. The atmosphere is an intermediate stage in the migration of microorganisms, therefore it can not serve - because of the lack of nutrients and insufficient humidity - a permanent habitat for bacteria. In the air, bacteria get into the dust, microscopic droplets of water, but then - settle, eventually, on the soil. However, in densely populated areas - large megacities, for example - the amount of microorganisms contained in the air can be great, especially in the summer. And the air itself can serve as a medium where pathogenic bacteria live , all kinds of infections. Some of them: diphtheria, whooping cough. And also tuberculosis caused by the stick of Koch.

On the man

On the human skin is a great many microorganisms. But they are unevenly distributed throughout the plane. There are bacteria "favorite" places, and there are areas resembling deserted deserts. And, according to scientists, the majority of microorganisms living on people's skin are not harmful. On the contrary, they perform a sort of protective function for a person from microbes that are considered dangerous. Scientifically proven that excessive sterility and cleanliness - not so good (of course, simple rules of hygiene still have not been canceled). The fewest bacteria are found behind the auricles. The main number is on the forearms (there there are up to 45 species). Many bacteria live on mucous membranes, so-called wet zones, where they feel very comfortable. In dry (palms, buttocks) - the conditions of existence are not entirely suitable for microorganisms.

Inside us

According to the doctors-microbiologists, about three kilograms of bacteria live in the human intestine ! And in quantitative terms - this is a huge army, which can not be ignored. However, bacteria are smart neighbors. The majority of people inhabiting the body (as well as other mammals) are useful and carry out a peaceful neighborhood with the "masters". Some - help digestion. Others - perform protective functions: as a result of their actions, pathogenic microorganisms are immediately destroyed when they attempt to enter the client's territory. 99% of the population - bifidobacteria and bacteroides. A enterococcus, E. coli (which is conditionally pathogenic), lactobacilli - from about 1 to 10%. They under adverse conditions can cause various diseases, but in the body of a healthy person perform useful functions. Still there live various fungi and staphylococci, which can also be pathogenic. But basically in the gastrointestinal tract there is a certain bacteriological balance, as if conceived by nature, maintaining human health at the proper level. And pathogenic microorganisms at sufficiently high immunity can not penetrate inside and cause harm.