In quantitative terms, these smallest living organisms are the most numerous inhabitants of land, seas, and atmosphere. According to scientists, more than one hundred million bacteria can live in just one gram of soil. And in relation to 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 since changed little! What is the role of bacteria in nature? What global processes are these microscopic creatures involved in? Which of them are useful and which are harmful to the human body? We will try to give short answers to all these questions in this article.
A bit about bacteria
Nature, creating bacteria, provided them with an unprecedented margin of safety and many qualities that are absent in most other inhabitants of the planet Earth. They are able to withstand high and low temperatures, quietly exist at high and low atmospheric pressure, with virtually no oxygen. Microorganisms, as it were, are intended to populate new worlds, to gain a foothold in unfamiliar, uninhabited territories. With a rather primitive structure (most are unicellular), bacteria have a huge margin of safety, and are perhaps the most effective of the known existing life forms.
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 magnifies objects many times over. Then scientists were able to discern them, as they say, with their own eyes. And before that, huge colonies of bacteria existed unnoticed, invisibly helping or causing harm to all of humanity. What is the role of bacteria in nature? Which of them help, and which harm? Let's see through the microscope!
The positive role of bacteria
These ancient inhabitants of the planet seem to take care of their 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 fields of influence: on nature, atmosphere, and man. Let us consider each of them in more detail.
Orderlies of nature
The thing is that many bacteria eat the dead remains of other creatures, being a kind of "janitors" that cleanse nature of unnecessary trash and do not allow waste to accumulate. 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 play the role of orderlies do.
Blue green algae
And these cyanobacteria, erroneously previously called algae, are able to participate in photosynthesis. The positive role of bacteria of this type lies in the mass production of oxygen. Scientists have determined that at the beginning of time it was these tiny organisms that began to shape the Earth’s atmosphere. As a result, she turned out to be exactly the way we used to feel her. Of course, in modern environmental conditions, not only blue-green algae produce oxygen as a result of photosynthesis. But still the championship and the lion's share are behind them. And without these bacteria, it would be impossible to form flora and fauna on the planet in the form in which they exist today.
Substance cycle
Another positive role of bacteria is participation in the global circulation of substances in nature. On land and at sea, in the air, there is a constant global exchange of elements. All substances on planet Earth go from one organism to another. Without microorganisms, such a transition would be simply impossible. The nitrogen cycle is the most studied by science, which consists of several stages: fixation, oxidation, reduction (by rotting or ammonification). In all three cases, the processes are carried out using certain groups of bacteria. These are nodule and aerobic microorganisms that are involved in the processes of protein decomposition and transformation. Scientists have revealed the participation of these microscopic creatures in the reproduction and conversion of carbon dioxide, sulfur, iron, phosphorus. Additional studies of these phenomena are currently underway.
Food chains
What is the role of bacteria in the context of the nutrition of living things? Although these organisms are microscopically small, they serve as food for some larger creatures. Which, in turn, is fed by others. Of course, for example, for humans, bacteria are not any significant part of nutrition. But indirectly, we still eat them, without noticing it ourselves. A vivid example is the products of barrel preservation and the whole "sour milk" (by the way, beer and wine are also the result of the work of bacteria and fungi). In the national cuisines of the peoples of the world, such products are always present.
For man
What is the role in the life of bacteria (for humans)? Microorganisms living in the intestines are friendly and spiteless "neighbors." These include bifidobacteria and bacteroids, as well as E. coli, enterococci, lactobacilli. All of them constitute a beneficial microflora and perform protective and digestive functions. It was found that in the entire intestine the mass of microorganisms is about three kilograms. This is quite a lot in percentage terms.
The negative role of bacteria
But these microorganisms play in the environment and human life not only a positive role. Some bacteria (approximately 1%) can have a harmful effect on our bodies under certain circumstances. Pathogens-parasites that can cause infectious diseases: plague, cholera, etc. are fraught with great danger. Of the less dangerous diseases are tonsillitis, pneumonia. Therefore, probably, scientists prefer to keep these small parasites under constant control.
Another negative role of bacteria is their participation in the deterioration of edible. Under certain conditions, they are able to "eat" food left out of the refrigerator in a fairly quick time. Then for people these products already become unsuitable.