In quantitative terms, these smallest livingorganisms - the most numerous inhabitants of land, seas, atmosphere. According to scientists, not one hundred million bacteria can live in just one gram of soil. And in terms of the settlement of the Earth, microorganisms occupy an honorable first place. After all, they appeared on the planet more than 3.7 billion years ago. And some of them have changed little since then! What is the role of bacteria in nature? What global processes are these microscopic creatures involved in? Which ones are beneficial and which ones are harmful to the human body? We will try to give short answers to all these questions in this article.
Little bit about bacteria
Природа, создавая бактерии, снабдила их unprecedented margin of safety and many qualities that most other inhabitants of the planet Earth lack. They are able to withstand high and low temperatures, quietly exist at high and low atmospheric pressure, with little or no oxygen. Microorganisms, as it were, are intended for settling new worlds, securing them in unfamiliar, still uninhabited territories. With a rather primitive structure (the majority are single-celled), the bacteria have an enormous margin of safety; they are perhaps the most effective known form of life.
Where do they live
These microorganisms are omnipresent, they live everywhere:on land, in the oceans and seas, in the air and even inside other organisms. There are a great many of them, myriads. Despite this, bacteria have become “familiar” to humans only recently, after the invention of an optical device that multiplies objects many times over. Then the scientists were able to see them, as they say, with their own eyes. Before that, huge colonies of bacteria existed undetected, invisibly helping or harming all of humanity. What is the role of bacteria in nature? Which ones help and which ones hurt? Let's look through the microscope!
The positive role of bacteria
These ancient inhabitants of the planet seem to care aboutits territory of habitat, bringing great benefits to the entire planet in general and to humanity in particular. The positive role of bacteria can be traced in various spheres of influence: on nature, atmosphere, man. Let us consider in more detail each of them.
Medics of nature
The fact is that many bacteria eatdead remains of other creatures, being a kind of "janitors", cleansing the nature of unnecessary rubbish and not allowing the accumulation of waste. In science, this phenomenon is called saprotrophy. Without this kind of bacteria, the world would simply suffocate from the mass of waste that must be constantly disposed of. This is what many microorganisms that act as orderlies are doing.
Blue-green algae
А эти цианобактерии, ошибочно ранее называемые algae, are able to participate in photosynthesis. The positive role of bacteria of this type is in the mass production of oxygen. Scientists have determined that at the beginning of time these very tiny organisms began to form the atmosphere of the Earth. As a result, it turned out to be just the way we used to feel it. Of course, in modern environmental conditions, as a result of photosynthesis, not only blue-green algae are produced by oxygen. But still the primacy and the lion’s share are behind them. And without these bacteria, it would have been impossible to form the flora and fauna on the planet in the form in which they exist today.
Cycle of substances
Another positive role of bacteria is participation inworld circulation of substances in nature. On land and at sea, the global exchange of elements constantly takes place in the air. All substances on planet Earth are moving from one organism to another. Without microorganisms, such a transition would simply be impossible. The process of nitrogen cycle, which consists of several stages: fixation, oxidation, reduction (by rotting or ammonification), is the most studied by science. In all three cases, the processes are carried out with the help of certain groups of bacteria. These are nodule and aerobic microorganisms that are involved in the processes of protein decomposition and transformation. Scientists have identified the participation of these microscopic creatures in the reproduction and transformation of carbon dioxide, sulfur, iron, phosphorus. Additional studies are currently underway on these phenomena.
Food chains
What is the role of bacteria in the context of nutrition of livingcreatures? Although microscopically small, these organisms serve as food for some of the larger creatures. Which, in turn, feed on others. Of course, for example, for humans, bacteria are not a significant part of the diet. But indirectly, we still eat them without noticing it. A vivid example is the products of cask canning and the whole “sour milk” (by the way, beer and wine are also the result of the labor of bacteria and fungi). In the national cuisines of the peoples of the world are always present similar products.
For man
What is the role in the life of bacteria (for humans)?Microorganisms living in the intestines are friendly and kindly "neighbors." These include bifidobacteria and bacteroids, as well as E. coli, enterococci, lactobacilli. All of them make up useful microflora and perform protective and digestive functions. It has been established that in the whole intestine the mass of microorganisms is about three kilograms. This is quite a lot in percentage.
The negative role of bacteria
But these microorganisms play in the environment andhuman life is not only a positive role. Some bacteria (about 1%) can have a pathogenic effect on our body under certain circumstances. Parasitic pathogens that can cause infectious diseases such as plague, cholera, etc., pose a great danger. Of the less dangerous diseases, we can call angina, pneumonia. Therefore, probably, scientists prefer to keep these little parasites under constant control.
Another negative role of bacteria is their participation.in the spoilage of food. Under certain conditions, they are able to "eat" food left outside the refrigerator in a fairly quick time. Then for people these products already become unsuitable.
