The oldest living organism on our planet. Its representatives not only survived for billions of years, but also have enough power to destroy all other species on Earth. In this article, we will look at what bacteria are.
Let's talk about their structure, functions, and also name some useful and harmful species.
Discovery of bacteria
Let's start our tour of the microbial kingdom with a definition. What does "bacteria" mean?
The term comes from the ancient Greek word for "wand". It was introduced into the academic lexicon by Christian Ehrenberg. These are non-nuclear microorganisms, consisting of one cell and not having 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 about ten thousand different types of these living creatures have been discovered so far. However, it is believed that there are more than a millionvarieties.
Anton Leeuwenhoek, a Dutch naturalist, microbiologist and fellow of the Royal Society of London, in 1676, in a letter to Great Britain, describes a number of the simplest microorganisms that he discovered. His message shocked the public, and a commission was sent from London to double-check this data.
After Nehemiah Grew confirmed the information, Leeuwenhoek became a world-famous scientist, the discoverer of the simplest organisms. But in his notes, he called them "animalcules".
Erenberg continued his work. It was this researcher who coined the modern term "bacteria" in 1828.
Robert Koch became a revolutionary in microbiology. In his postulates, he associates microorganisms with various diseases, and defines some of them as pathogens. In particular, Koch discovered a bacterium that causes tuberculosis.
If before that the protozoa 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, American scientist Carl 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.
Building
About what bacteria are, 3rd grade already knows firsthand. Children study the structure of microorganisms in the classroom. Let's delve a little deeper into this topic to restoreinformation. Without her, it will be difficult for us to discuss subsequent points.
The bulk of bacteria consists of only one cell. But it comes in different shapes.
The structure depends on the mode of life and nutrition of the microorganism. So there are cocci (round), clostridia and bacilli (rod-shaped), spirochetes and vibrios (tortuous), in the form of cubes, stars and tetrahedra. It has been observed that with a minimum amount of nutrients in the environment, bacteria tend to increase the surface area. They grow additional formations. Scientists call these outgrowths "prostek."
So, after we have found out what forms of bacteria are, it is worth touching on their internal structure. Unicellular microorganisms have a permanent set of three structures. Additional elements may vary, but the base will always be the same.
So, each bacterium necessarily has an energy structure (nucleotide), non-membrane organelles responsible for protein synthesis from amino acids (ribosomes) and a protoplast. The latter includes the cytoplasm and the cytoplasmic membrane.
From aggressive external influences, the cell membrane is protected by a shell, which consists of a wall, a capsule and a sheath. Some species also have superficial formations like villi and flagella. They are designed to help bacteria move efficiently in space to get food.
Metabolism
After we figured out what bacteria are, their types of foodbecome obvious. These microorganisms are divided into two groups - heterotrophic and autotrophic. The former include a variety of parasites that cannot process the substances received 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.
It is especially worthwhile to dwell on heterotrophic bacteria. Different species need a certain amount of substances. For example, Bacillus fastidiosus is found only in urine, as it can only obtain carbon from this acid. We will talk about such microorganisms in more detail later.
Now it is worth dwelling on methods of replenishing energy in the cell. Such 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. Oxygen photosynthesis requires ordinary chlorophyll. These include prochlorophytes and cyanobacteria.
Recently a discovery has been made. Scientists have discovered microorganisms that use hydrogen obtained from the breakdown of water for reactions in the cell. But that is not all. This reaction requires the presence of uranium ore nearby, otherwise the desired result will not work.
Also, in the deep layers of the oceans and at its bottom, there are colonies of bacteria that transfer energy only fromelectric current.
Reproduction
Earlier, we talked about what bacteria are. We will consider the types of reproduction of these microorganisms now.
There are three methods by which these creatures increase their numbers.
This is sexual reproduction in its primitive form, budding and equal division.
In sexual reproduction, offspring are 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 varieties. Therefore, single-celled beings are able to survive various cataclysms 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 dead representatives of flora and fauna. In addition, microorganisms are involved in the creation of minerals and are responsible for maintaining the reserves of oxygen and carbon dioxide in the atmosphere of our planet.
The 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 beneficial, but also pathogenic species of bacteria. They cause many deadly diseases. For example, amongsuch are tuberculosis, leprosy, plague, syphilis, anthrax, and many others. But even those that are conditionally safe for human life can become a threat when the level of immunity decreases.
There are also bacteria that infect animals, birds, fish and plants. Thus, microorganisms are not only in symbiosis with more developed beings. Next, we will talk about what pathogenic bacteria are, as well as useful representatives of this type of microorganisms.
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 used the amazing ability of lactic acid bacteria. Without these microorganisms, there would be no kefir, no yogurt, no cheese in our diet. In addition, such creatures are also responsible for the fermentation process.
In agriculture, bacteria are used in two ways. On the one hand, they help to get rid of unnecessary weeds (phytopathogenic organisms, like herbicides), on the other hand, from insects (entomopathogenic unicellular, like insecticides). In addition, humanity has learned how to create bacterial fertilizers.
Microorganisms are also used for military purposes. With the help of various species, deadly biological weapons are created. To do this, not only the bacteria themselves are used, but also the toxins they secrete.
In a peaceful way, science uses unicellularorganisms 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 a person were created.
Bacteria are used in other areas as well. With the help of microorganisms, ores are enriched and water bodies and soils are cleaned.
Also, scientists say that the bacteria that make up the microflora in the human intestine can be called a separate organ with its own tasks and independent functions. According to researchers, there are about one kilogram of these microorganisms inside the body!
In everyday life, we encounter pathogenic bacteria everywhere. According to statistics, the most colonies are on the handles of supermarket carts, followed by computer mice in Internet cafes, and only in third place are the handles of public restrooms.
Next, we will talk about what beneficial bacteria are simply necessary for a person to function optimally.
Good bacteria
Even at school they teach you 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 thought about such a question as the state of the microflora in the intestines. Everything was OK. Eating more natural and he althy, less hormones and antibiotics, less chemical emissions into the environment.
Today, in conditions of poor nutrition, stress, an overabundance of antibioticsdysbacteriosis and related problems come to the forefront. How do doctors suggest dealing with this?
One of the main answers is the use of probiotics. This is a special complex that repopulates the human intestines with beneficial bacteria.
Such an intervention can help with such unpleasant moments as food allergies, lactose intolerance, disorders of the gastrointestinal tract and other ailments.
Let's now touch on what beneficial bacteria are, and also learn about their impact on he alth.
The most studied and widely used for a positive effect on the human body are three types of microorganisms - acidophilus, Bulgarian bacillus and bifidobacteria.
The first two are designed to stimulate the immune system, as well as reduce the growth of some harmful microorganisms such as yeast, E. coli and so on. Bifidobacteria are responsible for the digestion of lactose, the production of certain vitamins and the reduction of cholesterol.
Bad bacteria
Earlier, we talked about what bacteria are. The types and names of the most common beneficial microorganisms were announced above. Next, we will talk about the "one-celled 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 faunadue to the diversity of bacteria.
There are those that are harmful only to humans, there are deadly to animals or plants. People have learned to use the latter, in particular, to destroy weeds and annoying insects.
Before delving into what harmful bacteria are, it is worth deciding on the ways they spread. And there are a lot of those. There are microorganisms that are transmitted through contaminated and unwashed food, airborne and contact routes, through water, soil or insect bites.
The worst thing is that just one cell, once in a favorable environment of the human body, is able to multiply up to several million bacteria within just a few hours.
If we talk about what kind of bacteria are, the names of pathogenic and beneficial ones are difficult to distinguish for a non-professional. In science, Latin terms are used to refer to microorganisms. In common speech, abstruse words are replaced by concepts - "E. coli", "causative agents" of cholera, whooping cough, tuberculosis and others.
Preventive measures to prevent disease are of three kinds. These are vaccinations and vaccines, interruption of transmission routes (gauze bandages, gloves) and quarantine.
Where do bacteria come from in urine
Some people try to monitor their he alth and take tests at the clinic. Very often, the presence of microorganisms in the samples is the cause of poor results.
We'll talk a little about what bacteria are in the urinelater. Now it is worth dwelling separately on where, in fact, single-celled creatures appear there.
Ideally, a person's urine is sterile. There can be no foreign organisms. The only way for bacteria to enter the secretions is at the site where waste is removed from the body. Specifically, in this case it would be the urethra.
If the analysis shows a small number of inclusions of microorganisms in the urine, then everything is normal so far. But with an increase in the indicator above the permitted limits, 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 kind of bacteria are in the bladder is completely incorrect. Microorganisms enter the secretions not from this organ. Scientists today identify several reasons leading to the presence of single-celled creatures in the urine.
- First, it's promiscuous.
- Second, diseases of the genitourinary system.
- Third, neglect of personal hygiene.
- Fourthly, decreased immunity, diabetes and a number of other disorders.
Types of bacteria in 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 get started. Lactobacillus is a representative of anaerobic organisms, a gram-positive bacterium. It must be in the human digestive system. The presence of it in the urine indicates some failures. Such an event is not critical, but it is an unpleasant wake-up call to the fact that you should seriously take care of yourself.
Proteus is also a natural inhabitant of the gastrointestinal tract. But the presence of it in the urine indicates a failure in the withdrawal of feces. This microorganism gets from food into urine only in this way. A sign of the presence of a large amount of proteus in the waste is a burning sensation in the lower abdomen and painful urination with a dark color of the liquid.
Very similar to the previous bacterium is Enterococcus fecalis. It enters the urine in the same way, multiplies rapidly and is difficult to treat. In addition, Enterococcus bacteria are resistant to most 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 to you, dear readers! Remember that personal hygiene is the best prevention.
