The oldest living organism on our planet. Its representatives not only survived for billions of years, but also have the strength to destroy all other species on Earth. In this article, we will consider what bacteria can be.
Let's talk about their structure, functions, and also we will name some useful and harmful types.
Bacteria discovery
Let's begin our tour of the realm of microorganisms with definition. What does "bacteria" mean?
The term comes from the ancient Greek word "wand." He was introduced into the academic lexicon by Christian Ehrenberg. These are nuclear-free microorganisms consisting of one cell and without a nucleus. Previously, they were also called "prokaryotes" (non-nuclear). But in 1970 there was a division into archaea and eubacteria. However, until now, more often this concept means all prokaryotes.
The science of bacteriology studies what bacteria are. Scientists say that at this time, about ten thousand different types of these living creatures have been discovered. However, there is an opinion that there are more than a million varieties of them.
Anton Levenguk, a Dutch naturalist, microbiologist and full member of the Royal Society of London, in a letter to the United Kingdom in 1676 describes a series of simple microorganisms that he discovered. His message shocked the public, a commission was sent from London in order to double-check this data.
After Nehemiah Grew confirmed the information, Levenguk became a world-famous scientist, the discoverer of the simplest organisms. But in the notes, he referred to them as "animalalki."
Erenberg continued his work. It was this researcher who coined the modern term “bacteria” in 1828.
Robert Koch became a revolutionary in microbiology. He in his postulates associates microorganisms with various diseases, and defines some of them as pathogens. In particular, Koch discovered a bacterium that causes tuberculosis.
If before this the simplest were studied only in general terms, then after 1930, when the first electron microscope was created, science made a leap in this direction. For the first time, a deep study of the structure of microorganisms begins. In 1977, the American scientist Karl Wese divides prokaryotes into archaea and bacteria.
Thus, it is safe to say that this discipline is only at the very beginning of development. Who knows how many more discoveries await us in the coming years.
Structure
Grade 3 already knows firsthand what bacteria are. Children learn the structure of microorganisms in the classroom. Let’s go a little deeper into this topic to restore information. Without it, it will be difficult for us to discuss the following points.
The bulk of bacteria consists of only one cell. But it comes in many forms.
The structure depends on the way of life and the nutrition of the microorganism. So there are cocci (round), clostridia and bacilli (rod-shaped), spirochetes and vibrios (sinuous), in the form of cubes, stars and tetrahedra. It is noticed that with a minimum amount of nutrients in the environment, bacteria tend to increase surface area. They grow additional education. Scientists call these outgrowths "simple."
So, after we figured out what forms of bacteria are, it’s worth touching on their internal structure. Unicellular microorganisms have a constant set of three structures. Additional elements may vary, but the foundation will always be the same.
So, each bacterium necessarily has an energy structure (nucleotide), non-membrane organoids responsible for the synthesis of protein from amino acids (ribosomes) and protoplast. The latter includes the cytoplasm and the cytoplasmic membrane.
From aggressive external influences, the cell membrane is protected by a membrane, which consists of a wall, capsule and cover. Some species also have surface formations such as villi and flagella. They are designed to help bacteria move efficiently in space in order to obtain food.
Metabolism
After we figured out what bacteria are, the types of food they become apparent. These microorganisms are divided into two groups - heterotrophic and autotrophic. The first include a variety of parasites that cannot process the resulting substances from the outside. They simply use ready-made compounds created by the host organism. The latter are capable of producing the necessary from inorganic compounds themselves.
Heterotrophic bacteria are especially worthwhile. Different species need a certain amount of substances. For example, Bacillus fastidiosus is found only in urine, since it can receive carbon only from this acid. We will talk about such microorganisms in more detail below.
Now it’s worth stopping at methods of replenishment of energy in a cell. Of these, modern science knows only three. Bacteria use photosynthesis, respiration, or fermentation.
Photosynthesis, in particular, can be both with the use of oxygen, and without the participation of this element. Purple, green and heliobacteria do without it. They produce bacteriochlorophyll. For oxygen photosynthesis, normal chlorophyll is required. These include prochlorophytes and cyanobacteria.
A recent discovery has been made. Scientists have discovered microorganisms that use hydrogen from the breakdown of water for reactions in the cell. But that is not all. For this reaction, the presence of nearby uranium ore is necessary , otherwise the necessary result will not work.
Also in the deep sea layers of the oceans and at the bottom there are colonies of bacteria that transmit energy only with the help of electric current.
Breeding
Earlier it was said about what bacteria are. Types of reproduction of these microorganisms we will consider now.
There are three methods by which these creatures increase their number.
This is sexual reproduction in a primitive form, budding and isometric transverse division.
During sexual reproduction, the offspring is obtained through transduction, conjugation and transformation.
Place in the world
Earlier we figured out what bacteria are. Now it’s worth talking about what role they play in nature.
Researchers say that bacteria are the first living organisms that appeared on our planet. There are both aerobic and anaerobic species. Therefore, unicellular creatures are able to survive various disasters that occur with the Earth.
The undoubted benefit of bacteria is the assimilation of atmospheric nitrogen. They are involved in the formation of soil fertility, the destruction of the remains of the dead representatives of flora and fauna. In addition, microorganisms are involved in the creation of minerals and are responsible for maintaining the supply of oxygen and carbon dioxide in the atmosphere of our planet.
Total biomass of prokaryotes is about five hundred billion tons. It stores more than eighty percent of phosphorus, nitrogen and carbon.
However, on Earth there are not only useful, but also pathogenic bacteria. They cause many deadly diseases. For example, among these are tuberculosis, leprosy, plague, syphilis, anthrax and many others. But even those that are conditionally safe for human life can become a threat with a decrease in the level of immunity.
There are also bacteria that infect animals, birds, fish and plants. Thus, microorganisms are not only in symbiosis with more developed creatures. Next, we will talk about what pathogenic bacteria are, as well as about useful representatives of this type of microorganism.
Bacteria and man
We have already figured out what bacteria are, how they look, what they can do. Now it’s worth talking about what their role is in the life of a modern person.
Firstly, for many centuries we have been using the amazing ability of lactic acid bacteria. Without these microorganisms, there would be neither kefir, nor yogurt, nor cheese in our diet. In addition, similar creatures are also responsible for the fermentation process.
In agriculture, bacteria use in two ways. On the one hand, they help get rid of unnecessary weeds (phytopathogenic organisms, like herbicides), and on the other, insects (entomopathogenic unicellular, like insecticides). In addition, humanity has learned to create bacterial fertilizers.
Microorganisms are also used for military purposes. Using various types of deadly biological weapons are created. To do this, not only the bacteria themselves are used, but also the toxins secreted by them.
In a peaceful vein, science uses single-celled organisms for research in genetics, biochemistry, genetic engineering, and molecular biology. With the help of successful experiments, algorithms for the synthesis of vitamins, proteins and other substances necessary for humans were created.
Bacteria are used in other areas. With the help of microorganisms, ore is enriched and water and soil are cleaned.
Scientists also say that the bacteria that make up the microflora in the human intestines can be called a separate organ with its own tasks and independent functions. According to researchers, there is about one kilogram of these microorganisms inside the body!
In everyday life, however, we encounter pathogenic bacteria everywhere. According to statistics, the largest number of colonies is located on the handles of supermarket carts, followed by computer mice in Internet cafes and only in third place are handles of public restrooms.
Further, we will talk about which beneficial bacteria are simply necessary for a person to have an optimal functioning of the body.
Beneficial bacteria
Back in school they teach what bacteria are. Grade 3 knows all sorts of cyanobacteria and other unicellular organisms, their structure and reproduction. Now we will talk about the practical side of the issue.
Half a century ago, no one even thought about such a question as the state of microflora in the intestine. Everything was OK. Nutrition is more natural and healthy, a minimum of hormones and antibiotics, less chemical emissions into the environment.
Today, in conditions of poor nutrition, stress, an excess of antibiotics, dysbiosis and related problems are gaining a leading position. How do doctors propose to deal with this?
One of the main answers is the use of probiotics. This is a special complex that re-populates the human intestines with beneficial bacteria.
Such an intervention can help with such unpleasant moments as food allergies, lactose intolerance, gastrointestinal upset and other ailments.
Now let's touch on what beneficial bacteria are, and also learn about their effects on health.
Three types of microorganisms - acidophilus, Bulgarian bacillus and bifidobacteria - have been most thoroughly studied and widely used for positive effects on the human body.
The first two are designed to stimulate immunity, as well as reduce the growth of some harmful microorganisms like yeast, Escherichia coli and so on. Bifidobacteria are responsible for digesting lactose, producing some vitamins and lowering cholesterol.
Harmful bacteria
Earlier we talked about what bacteria can be. The types and names of the most common beneficial microorganisms were announced above. Next, we will talk about the "unicellular enemies" of man.
So, first of all, let's find out the features of pathogenic bacteria. Their main weapon against more advanced creatures is toxins. With the help of such substances, they poison the cells of organisms on which they parasitize. It is a large number of representatives of flora and fauna that determines the diversity of bacteria.
There are those that are harmful only to humans, there are deadly for animals or plants. People learned to use the latter, in particular, to destroy weeds and annoying insects.
Before delving into what kind of harmful bacteria are, it is worth determining the ways of their distribution. And there are a lot of those. There are microorganisms that are transmitted by contaminated and unwashed products, by airborne droplets and contact routes, through water, soil, or through insect bites.
The worst thing is that only one cell, once in a favorable environment of the human body, can multiply up to several million bacteria in just a few hours.
If we talk about what bacteria are, the names of pathogens and useful ones are difficult to distinguish between non-professionals. In science, Latin terms are used to refer to microorganisms. In vernacular, abstruse words are replaced by concepts - “E. coli”, “pathogens” of cholera, whooping cough, tuberculosis and others.
Preventive measures to prevent the disease are of three types. These are vaccinations and vaccines, interruption of transmission routes (gauze dressings, gloves) and quarantine.
Where do the bacteria in urine come from?
Some people try to monitor their health and take tests at the clinic. Very often the cause of poor results is the presence of microorganisms in the samples.
We will talk about what bacteria are in the urine a little later. Now it is worthwhile to dwell separately on where, in fact, unicellular creatures come from.
Ideally, human urine is sterile. There can be no extraneous organisms. The only way bacteria can get into the discharge is at the place where the waste is removed from the body. In particular, in this case it will be the urethra.
If the analysis shows a small number of inclusions of microorganisms in the urine, then so far everything is normal. But with an increase in the indicator above the permitted boundaries, such data indicate the development of inflammatory processes in the genitourinary system. This may include pyelonephritis, prostatitis, urethritis and other unpleasant ailments.
Thus, the question of what bacteria are in the bladder is completely incorrect. Microorganisms are not excreted from this organ. Scientists today identify several reasons leading to the presence of unicellular creatures in the urine.
- Firstly, it is an erratic sex life.
- Secondly, diseases of the genitourinary system.
- Thirdly, neglect of personal hygiene.
- Fourth, a decrease in immunity, diabetes and a number of other disorders.
Types of bacteria in the urine
Earlier in the article, it was said that microorganisms in waste products are found only in case of diseases. We promised to tell you what bacteria are. Names will be given only of those species that are most often found in the results of analyzes.
So, let's begin. Lactobacillus is a representative of anaerobic organisms, a gram-positive bacterium. It should be in the human digestive system. The presence of it in the urine indicates some malfunctions. Such an event is uncritical, but it is an unpleasant call to the fact that you should seriously take care of yourself.
Proteus is also a natural inhabitant of the gastrointestinal tract. But its presence in the urine indicates a malfunction in the excretion of feces. This microorganism passes from food to urine only this way. A sign of the presence of a large amount of proteus in the waste is burning in the lower abdomen and painful urination with a dark liquid color.
Enterococcus feces is very similar to the previous bacterium. It enters the urine in the same way, multiplies rapidly and is difficult to treat. In addition, enterococcus microorganisms are resistant to the bulk of antibiotics.
Thus, in this article we figured out what bacteria are. We talked about their structure, reproduction. You have learned the names of some harmful and beneficial species.
Good luck, dear readers! Remember that personal hygiene is the best prevention.