Microbes are the smallest living, mostly unicellular organisms that can only be seen through a very precise microscope. Their size is so small that it is measured in micrometers (1 μm = 1/1000 mm) or even nanometers (1 nm = 1/1000 μm).
What microbiology studies
Microbiology is the name of science, which explores the sphere of life of microorganisms: structure, functioning, living conditions, development and reproduction.
The first person who managed to examine and describe microbes was the Dutchman A. Levenguk. At sunset of the 17th century, he made lenses that magnify the image by more than 200 times. He was shocked by the fact that he saw through them that microbes are a whole world with its own characteristics of existence. So the foundation was laid for a new science - microbiology. Levenguk illustrated and described the discovered microbes. Photos and pictures with their image of those times are filmed magnifications through a microscope.
Types of germs
The countless variety of microorganism species is impressive. Microbes are the short name for hundreds of their many different types. They differ among themselves in appearance, structure, living conditions, and ability to reproduce. There are non-cellular, multicellular and unicellular microbes. Photos with their visualization help to easily relate each individual to a particular species. Microbe Classification:
- bacteria
- viruses;
- phages;
- mushrooms;
- microalgae;
- protozoa;
- yeast.
Bacteria
A whole section of microbiology - bacteriology - opens up a huge world of bacteria - prokaryotic organisms. They differ from eukaryotes (multicellular, protozoa, algae, fungi) in the absence of chlorophyll, a formed nucleus with genetic material and organoids. The size of the bacterium is variable, may vary depending on the external environment (from 0.1 to 28 microns). The most popular classification of bacteria is by morphological structure.
Cocci
Cocci are called spherical microbes that can take a spherical, bean-shaped, ellipsoidal or lanceolate shape.
- Micrococci can be located one at a time, in pairs or randomly. They are called saprophytes, live in water and air.
- Diplococci multiply by dividing in the same plane two pieces. These include meningococci (carriers of meningitis) and gonococci.
- Streptococci are similarly divided in one plane, but in whole chains. Known pathogenic for the human body species that transmit angina and various erysipelas.
- Tetracocci are arranged in two pieces on two planes, mutually perpendicular. Pathogenic individuals are very rare.
- Sardines are characteristic bales of cells of 8, 16 or more on three mutually perpendicular planes. Almost all of their representatives live exclusively in the air.
- Staphylococci can divide simultaneously in several planes located randomly relative to each other, in appearance they resemble grape clusters.
Rod-shaped
Cylindrical microorganisms are much more common than other species. They are divided into bacteria that do not have the ability to form spores (diphtheria, dysentery, tuberculosis, partiosis, Escherichia coli), and bacilli capable of creating spores (anthrax, hay, tetanus, anaerobic). Classification by the method of division:
- Diplobacteria, diplobacilli differ in the location of only two cells in one plane (pneumonia).
- Streptobacteria, streptobacilli in the process of division occupy one plane on which a whole chain is built (anthrax).
- The main part of cylindrical microbes are randomly located in one individual.
Twisted
Curved microbes can take the form of a comma, these are vibrios (for example, cholera). Spirillas have several curls, spirochetes are thin convoluted sticks (syphilis).
It is important to note that all microbes and bacteria are polymorphic, they have a unique ability to change their shape under the influence of various factors: the external environment, temperature, acidity, etc. It is this ability that underlies many laboratory studies of microbes aimed at developing medical products that will help in the future to fight bacteria that are pathogenic to humans.
Viruses
Viruses are a large community of microbes that differs from others in the absence of a cellular structure per se. Of the sizes, the sizes of bacteria are incomparably smaller: from 5 to 150 nm. To see them, you will have to set the electron microscope to the highest level of accuracy. Most representatives of viral microorganisms consist only of protein and nucleic acid (RNA, DNA).
Some microbes and viruses can be the causative agents of many serious human diseases (flu, hepatitis, measles). In addition, there are species pathogenic for animals (plague, foot and mouth disease).
Mycophages are fungal viruses. Bacteriophages are bacterial viruses; they live almost everywhere where there is at least some life. Some phages have a very useful ability - to destroy a microbial cell, therefore they are often used in the manufacture of drugs for the prevention and treatment of various types of infections.
Rickettsia is a special kind of microbes that can be attributed to both bacteria and viruses. These are immobilized rod-shaped intracellular parasites, unable to form spores or capsules.
Mushrooms
These are special microorganisms of plant origin, deprived of chlorophyll and the ability to synthesize organic substances. Moreover, their life requires ready-made organic substances, so almost all of them grow on the basis of substrates of different origin. There are some types of fungi pathogenic for humans, animals and plants.
Fungi differ from bacteria in that their cells are more like plant cells, have nuclei and vacuoles. They are presented in the form of hyphae - long threads that can branch and intertwine with each other.
Mushrooms can multiply in several ways: vegetative division, asexual and sexual - the formation of spores. Spores of fungi are characterized by high resistance; they can live for a long time in a different external environment and travel over great distances until they get into the nutrient medium, where they quickly transform into hyphae.
Mold fungi are very common to us, they can be easily seen with the naked eye on spoiled foods. They look like a curd coating of a heterogeneous color. There are some types of mushrooms that do not just spoil the products; they produce mitoxin, toxic to humans and animals, such as aspergillus or fusarium.
However, mushrooms are not always harmful, their many beneficial properties are successfully used by manufacturers of medicines. The most effective and popular antibiotic penicillin is made on the basis of mushrooms from the type of penicillin.
Actinomycetes are an exceptional type of microorganism that has the structure and properties of bacteria and a method of reproduction similar to fungi.
Yeast
These are immobilized unicellular microbes ranging in size from 10 to 15 microns, which can have a round, oval, in rare cases, cylindrical and sickle-shaped. Yeast is similar in structure to mushrooms; it contains vacuole and core. Possible methods of reproduction are division, budding, or through spores. They develop rapidly in soil, food, plants. Yeast on the surface of food products leads to their fermentation and souring. Alcoholic fermentation transforms sugar into alcohol, this process is the basis of the alcohol industry and home winemaking.
There are types pathogenic for the human body. For example, a fairly common genus of Candida yeast contributes to the spread of an unpleasant disease - candidiasis.
Useful microbes in the human body
The human body is populated by trillions of various bacteria that can be both harmful and beneficial. There are bacteria that are vital for the normal functioning of our body. The total weight of bacteria in an adult can reach 4 kg, and ¾ of them live in our intestines. The rest feel great in the genitourinary system, on the surface of the skin and mucous membranes. Interestingly, the baby's body is colonized by microorganisms already in the process of its birth, and by the age of 10 the intestinal microflora is already fully formed. Some microbes for children are extremely dangerous, so the first year of life, the hygiene of the child's body must be very thorough.
What microbes live in the intestines:
- lactobacilli;
- bifidobacteria;
- streptococci;
- enterobacteria;
- mushrooms;
- protozoa;
- viruses.
The benefits of bacteria for humans
- With the help of enterobacteria, the body assimilates vitamins of groups B, C, K, nicotinic and folic acid.
- Help digest unsplit food.
- Support ion and water-salt metabolism.
- They inhibit the growth of pathogenic microorganisms.
- Contribute to the maintenance of immunity.
- Develop a lymphoid apparatus.
- Reduce the sensitivity of the intestinal wall to carcinogenic products.
- Increase virus resistance.
- Actively participate in the heat balance.
Bifidobacteria and lactobacilli occupy more than half of the intestinal microflora, they play an important role in the life of a healthy person:
- Lactic acid and acetate, produced with the participation of these microorganisms, can create an environment in the intestine in which pathogenic microbes cannot live.
- Bifidobacteria - a natural antihistamine, suppresses allergic reactions in the body.
- They have an antioxidant effect and fight the growth of tumor cells.
- Bifidobacteria are actively involved in the production of B vitamins.
- Bifidobacteria and lactobacilli increase the percentage of human absorption of iron, calcium and vitamin D.
The value of germs for nature
Bacteria containing ammonifying enzymes, initiatively contribute to the process of decay of the remains of people, animals, plants and food waste. During protein decomposition, very important gases are released into the atmosphere: ammonia and nitrogen, which are vital for humans, animals, and plants.
Urobacteria can decompose the urea produced daily by every person and animal. And this, by the way, is at least 55 million tons every year.
Microbes capable of nitrification oxidize ammonia. Denitrifying microorganisms contribute to the release of molecular oxygen from the soil.
Carbon is one of the most important cellular substances in the world of plants and animals. Fiber, which many animals eat, contains a lot of carbon. In their stomachs, with the help of cellulose bacteria, it is fermented and goes back into nature with manure. Thus, the earth receives humus, becomes much more fertile, and the atmosphere is saturated with carbon dioxide.
Thus, bacteria and microbes are a very important component of the entire living world. Many beneficial bacteria constantly accompany a person throughout life and protect our body from unwanted external influences. It is very important not to upset the delicate and fragile balance between beneficial and pathogenic microorganisms.