There is a comic saying that the aliens, having arrived on Earth, for a long time could not understand who is in charge on it - bacteria or people. What do we know about these invisible to the eye, but so necessary for all living organisms?
Long life
Bacillus and bacteria denote one and the same microorganism, the first word came to us from Latin, the second from Greek, translated means "stick".
According to scientists, these ancient unicellular organisms appeared more than 3.5 billion years ago, and for many millions of years they were the only inhabitants of the Earth. Their evolutionary process was successful, so the appearance remained unchanged, in contrast to the internal structure.
Such a phenomenon is named - "Volkswagen syndrome". It is known that the car "Volkswagen Beetle", which appeared on sale in the late 30s, was very popular with the buyer. This allowed manufacturers not to change the exterior of the car for forty years.
The bacteria were discovered by the Dutch naturalist Levenguk in the second half of the 17th century, and the name was given by the German scientist Ehrenberg in 1828. Even on Mars found such "dormant" microorganisms, which, according to American scientists, can serve as evidence of the existence of life on other planets.
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Cell device and properties
A bacterium is a single-cell organism. It reproduces by division, the rate of which depends on the habitat. The more favorable it is, the faster the process goes. Less common are colonial forms - accumulations that form on the surface or inside nutrient compositions.
The main feature of the cell is the absence of a nucleus, therefore it has another name - prokaryotes (prenuclear). There is only a slimy capsule that has a protective function, for example, prevents drying out.
In shape, they are round (cocci), convoluted (spirochetes), rod-shaped (bacilli), stellate, cubic.
The average size of the bacillus is from 0.5 to 5 microns. But there are also larger ones, for example, the "gray pearl of Namibia", found in 1999. The size of the "pearl" is up to 0.75 mm, it can be seen even with the naked eye.
Microorganisms live in a wide variety of environments: water, air, soil, food, on bodies. Interestingly, they are found in the most extreme conditions that are impossible for the survival of other organisms - in the permafrost of glaciers or in active volcanoes, where the temperatures are highest. The most "thermophilic" bacillus - thermoacidophila, exists at temperatures not lower than 55 ° C in acidic springs.
Interesting Facts
Only with the advent of electron microscopes was it possible to learn a lot about nuclear-free microorganisms:
• most of them were found on the trolleys of large stores (1100 colonies per 10 sq. Cm), many on computer "mice" in Internet cafes, on mobile phone cases;
• there are more than 5 nonillions of them on Earth - more than people and all animals combined;
• the intestines of a newborn baby are sterile, but with the first breath they receive millions of prokaryotes. In total, the human body contains about 2 kg of bacteria, including 1000 different species.
• in homes, leaders in the number of bacilli are vegetable and meat compartments of refrigerators, can openers and silicone spatulas;
• snowflakes and frost on plants form nuclear-free organisms;
• Japanese people have a unique bacterium in their intestines that helps digest all types of seafood.
Bacilli improve the digestive process in ruminants by helping to digest cellulose.
Application area
Bacteria are used in the national economy, in medicine, in the food and chemical industries and in other fields.
With their help, lactic acid products, acetic acid, acetone, alcohol are produced; in medicine it is used in the manufacture of enzymes, vitamins and hormones.
Currently, there are techniques that use phytopathogenic bacilli as herbicides, as well as replacement insecticides. Bacterial fertilizers are widely used in rural production.
Nuclear-free organisms multiply and grow rapidly. These properties are used in genetic research, biochemistry, and genetic engineering.
In the future, prokaryotes are planned to be used for enrichment of ores and purification of reservoirs and soil contaminated with oil products.
In addition to useful properties, there are also negative ones: bacteriological weapons are produced from toxins harmful to humans. Food is spoiled precisely because of activity, it also makes food poisonous.
Myths debunked
Some information about microorganisms is not always true enough, and sometimes contradicts popular opinion.
For example, air hand dryers in toilets are not nearly as dangerous as doorknobs.
It is believed that there are no bacteria on airplanes. During inspections, it was found that intestinal bacteria are present in the water. A large number of microorganisms have been identified in air conditioners through which air enters the passenger compartment.
It has long been believed that if a dog licks a person's wound, it will be disinfected. Indeed, dog saliva has bactericidal properties, but only kills a small fraction of the microbes.
Bacilli accumulate on the sponges used by housewives in the kitchen; to disinfect them, they should be disinfected daily in a microwave oven for 30 seconds. Bactericidal soap has no advantages over conventional soap.
It is not true that the appendix is just a rudiment, it turns out that it is important for the immune system, because it contains beneficial prokaryotes.
The most dangerous
Conventionally nuclear-free protozoa are divided into harmful, neutral and useful. Some of them are causative agents of diseases that can lead to death: typhoid, tuberculosis, tetanus, tonsillitis and others. Infection occurs not only by airborne droplets, but through water, household items.
The most dangerous for humans are:
1. Salmonella - cause severe typhoid fever. If antibiotic treatment is not immediately started, a person can die, there are up to 260 thousand deaths a year.
2. Tetanus is also an extremely dangerous disease that kills 58 thousand people a year.
3. Staphylococcus aureus, leading to both mild skin infections and very serious - osteomelitis, endocarditis, toxic shock and sepsis.
4. Syphilis - in the first and second stages, it is easy to treat. A neglected form requires a long course.
It is difficult to list all the diseases caused by prokaryotes: pneumonia and bacterial meningitis and others, vaccines have been invented against most.
Do not forget about the simplest means of protection and prevention - personal hygiene, frequent hand washing with soap and water.
Until 1930, protozoa were known only in general terms, and with the advent of the electron microscope, a breakthrough was made in this direction. Scientists believe that the study of this unique organism is just beginning. Most likely, sensational discoveries await us in the coming decades.