Bacteria are undoubtedly the oldest creatures on Earth. They are involved at every stage of the cycle of substances in nature. Over billions of years of its life, bacteria have taken control of processes such as fermentation, decay, mineralization, digestion, and so on. Small, invisible fighters are everywhere. They live on various objects, on our skin and even inside our body. To fully understand their diversity, it may take more than one life. Nevertheless, we will try to consider the main forms of bacteria, paying special attention to spherical unicellular organisms.
The kingdom of bacteria, or What microbiology studies
Wildlife is divided into 5 major kingdoms. One of them is the kingdom of bacteria. It combines two sub kingdoms: bacteria and blue-green algae. Scientists often call these organisms nibs, which reflects the process of reproduction of unicellular data, reduced to "crushing", that is, division.
Microbiology is studying the kingdom of bacteria. Scientists in this area systematize living organisms into kingdoms, analyze morphology, study biochemistry, physiology, the course of evolution and their role in the planet’s ecosystem.
The general structure of bacterial cells
All major forms of bacteria have a special structure. They lack a nucleus surrounded by a membrane capable of separating it from the cytoplasm. Such organisms are commonly called prokaryotes. Many bacteria are surrounded by a mucous capsule that causes resistance to phagocytosis. A unique feature of the representatives of the kingdom is the ability to reproduce every 20-30 minutes.
Bacterial cells can have a different shape based on which they are classified:
- Cocci bacteria (spherical).
- Rod-shaped (bacillus bacteria).
- Curved and bent bacteria (vibrios and spirillas).
- Chained bacteria (streptococci).
- Cluster-like forms (staphylococci).
Consider in more detail spherical bacteria, having the common name cocci.
Spherical (cocci): general information about bacteria
The term coccus came to microbiology from Latin. Its meaning is “spherical”, “spherical”. Although there is a version that the term refers to the Greek language, and its meaning is “grain”. In both cases, the name reflects the appearance of the microorganism. This means that spherical bacteria have a rounded shape. Sometimes the cell can be somewhat elongated and approach the oval in shape, some organisms are slightly flattened from the sides. All bacteria of this species are motionless and incapable of spore formation. The average diameter of cocci is 0.5-1.5 microns.
Spherical bacteria live in soil, in the air, on products. Once in a favorable environment, the cell actively begins the process of reproduction. White, gray, yellow or red bacterial colonies form on the surface. In the process of reproduction, each spherical individual is split in two in any plane. After division, the spherical bacteria either remain independent or combine with other cocci.
Subdivision into species
The group of spherical bacteria is heterogeneous. Inside it there is a division into various types:
- gram-positive spherical micrococci;
- rounded paired diplococci;
- streptococci connected in a bacterial chain;
- forming a square of tetracoccus as a result of division;
- forming a cube of sarcinas as a result of division;
- staphylococci that breed in spontaneous directions.
All these cocci bacteria have their own characteristics, which are not only in the method of division. This requires a more detailed description for each species.
Features of micrococci
Micrococci are located on the surfaces of single individuals or irregular clusters. When the micrococcus is placed on a dense nutrient medium , the formation of rounded smooth colonies of several colors (white, yellow, red) will be observed. Color depends on the pigmentation of the cell or the release of the stained product into the environment.
Micrococci are obligate aerobes. This means that they need oxygen to breathe. By the method of nutrition, these bacteria (spherical micrococci) are saprophytes, or optional parasites. That is, they are able to receive nutrients for development and growth from dead or decomposed tissues or feed on the tissues of another organism.
Micrococci are not pathogenic, that is, they do not interfere with normal life, working capacity and tissue integrity. Most of these microorganisms develop in the temperature range from 25 to 30 ° C. But some of them go beyond this range and are capable of multiplying at a temperature of 5-8 ° C or do not die when heated to 60-65 ° C.
In the human body, micrococci are found on the skin, in the oral cavity, in the respiratory tract. Occasionally on the genitals or conjunctiva.
Features of the spherical bacteria diplococcus
Also, spherical bacteria include diplococci. These spherical bacteria exist in pairs. It was such a feature that became the basis for the appearance of the term "diplococcus". It is formed from the Greek word diploos, which can be translated as "double". Medicine has identified about 80 types of double bacteria. In the body, they are often protected by a capsule, which is a mucous formation with a thickness of not more than 0.2 microns. The capsule always has a strong connection with the cell walls of bacteria, it can be distinguished in smears of pathological materials. Diplococci relate to both gram-negative and gram-positive bacteria. They are pathogenic. Examples of globular bacteria related to diplococci are gonococci, pneumococci, and meningococci. They are the causative agents of gonorrhea, croupous pneumonia and meningitis.
Gonococcus has the status of the most pathogenic variety of diplococci. These pathogenic cocci are in the form of a double bean. But in some cases, they can lose their typical shape and form clusters of bacteria. To detect gonococci, a smear is taken and the number of leukocytes in the blood is determined. Today, gonorrhea is the most common sexually transmitted disease. The disease is sexually transmitted.
Pneumococci excite not only croupous pneumonia, but also otitis media or sinusitis. The bacterium has a double lanceolate shape. It is motionless, and its size does not exceed 1.25 microns. Pneumococcus is a gram-positive bacterium.
Meningococcus is a paired bacterium that resembles buns sticking together at the base. In appearance, it somewhat resembles a gonococcus. The scope of meningococci is the mucous membrane of the brain. Patients with suspected meningitis must be hospitalized.
Staphylococci and streptococci: features of bacteria
Consider two more bacteria whose spherical forms bind into chains or develop in spontaneous directions. These are streptococci and staphylococci.
Streptococci are numerous in the microflora of humans. When dividing, these spherical bacteria create beads or chains of microorganisms. Streptococci can cause infectious and inflammatory processes. Favorite places of localization are the oral cavity, gastrointestinal tract, genitals and mucous membranes of the respiratory tract.
Staphylococci are divided in many planes. They create grapes from bacterial cells. They can cause inflammatory processes in any tissues and organs.
What conclusions should humanity draw
Man is too accustomed to being the king of nature. Most often, he bows only before brute force. But on the planet there is a whole kingdom in which organisms invisible to the eye are united. They have the highest adaptability to the environment and affect all biochemical processes. Smart people have long understood that “small” does not mean “useless” or “safe”. Without bacteria, life on Earth will simply stop. And without careful attention to pathogenic bacteria, it will lose quality and will gradually die out.