Bacteria globular (cocci, micrococci, diplococci): structure, dimensions, mobility

No doubt, bacteria are the most ancient creatures on Earth. They are involved at every stage of the cycle of substances in nature. For billions of years of its life, bacteria have taken control of such processes as fermentation, decay, mineralization, digestion and so on. Small, invisible fighters are everywhere. They live on different objects, on our skin and even inside our body. To fully understand their diversity, it may take more than one life. Still, let's try to consider the main forms of bacteria, paying special attention to globular unicellular organisms.

The Kingdom of Bacteria, or What Microbiology Studies

The living nature is divided into 5 main kingdoms. One of them is the kingdom of bacteria. It combines two sub-kingdoms: bacteria and blue-green algae. Scientists often call these organisms crushed, which reflects the process of multiplication of unicellular data, reduced to "fragmentation," that is, division.

The study of the kingdom of bacteria is concerned with microbiology. Scientists of this direction systematize living organisms in the kingdoms, analyze morphology, study biochemistry, physiology, evolution and the role in the ecosystem of the planet.

General structure of bacterial cells

All the main 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 different forms from which they are classified:

1. Bacteria cocci (globular).
2. Rod-shaped (bacteria bacilli).
3. Crimped and curved bacteria (vibrios and spirillae).
4. Chain-shaped bacteria (streptococci).
5. Grozdevidnye forms (staphylococci).

Let us consider in more detail the bacteria globular, having a common name for cocci.

Globular (cocci): general information on bacteria

The term coccus came to microbiology from Latin. Its meaning is "spherical", "spherical". Although there is a version that the term has to do with the Greek language, and its meaning is "grain". In both cases, the name reflects the appearance of the microorganism. This means that the globular bacteria have a rounded shape. Sometimes the cell can be somewhat stretched and in shape to approach the oval, some organisms are slightly flattened from the sides. All bacteria of this species are immobile and incapable of sporulation. The average diameter of the cocci is 0.5-1.5 μm.

Bacteria of spherical form live in soil, in air, on products. Getting into a favorable environment, the cell actively begins the process of reproduction. White, gray, yellow or red bacterial colonies are formed on the surface. In the process of reproduction, each globular individual is split in two in any plane. After division, the bacteria are spherical or remain independent, or combined with other cocci.

Division into Species

The group of globular bacteria is not homogeneous. Within it there is a division into different types:

• Gram-positive spherical micrococci;
• Rounded paired diplococci;
• Streptococci, bound in a bacterial chain;
• Forming as a result of division a square of tetracoccus;
• Forming a cube of sarcin as a result of division;
• Multiplying in the spontaneous directions of staphylococci.

All these cocci bacteria have their own characteristics, which are not only in the way of division. This requires a more detailed description for each species.

Features of micrococci

On the surfaces of the micrococcus are located 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. The color depends on the pigmentation of the cell or the release of the colored product into the environment.

Micrococci are obligate aerobes. This means that they need oxygen for breathing. By way of nutrition, these bacteria (globular micrococci) are saprophytes, or facultative parasites. That is, they are able to receive nutrients for development and growth from dead or decayed tissues or feed on the tissues of another organism.

Micrococci are not pathogenic, that is, they do not interfere with normal vital activity, working capacity and integrity of tissues. 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 perish when heated to 60-65 ° C.

In the human body, micrococci are found on skin integuments, in the oral cavity, in the respiratory tract. Occasionally on the genitals or conjunctiva.

Features of the globular bacterium diplococcus

Also, globular bacteria include diplococci. These spherical bacteria exist in pairs. This particular feature became the basis for the appearance of the term "diplokokk". It is formed from the Greek word diploos, which can be translated as "double". The medicine has isolated about 80 types of double bacteria. In the body, they are often protected by a capsule, which is a mucous formation of not more than 0.2 μm in thickness. The capsule always has a strong connection with the bacterial cell walls, it can be discerned in smears of pathological materials. Diplococci refer 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 a cluster of bacteria. For the detection of gonococci, a smear is taken and the number of leukocytes in the blood is determined. Today gonorrhea is the most common venereal disease. The disease is transmitted sexually.

Pneumococci not only excite croupous pneumonia, but also otitis or sinusitis. The bacterium has a double lanceolate shape. It is stationary, and its size does not exceed 1.25 microns. Pneumococcus is a gram-positive bacterium.

Meningococcus is a paired bacterium, similar to the buns stuck together by the base. Appearance somewhat resembles a gonococcus. The sphere of action of meningococci is the mucous membrane of the brain. Patients with suspected meningitis must be hospitalized.

Staphylococci and streptococci: features of bacteria

Let's consider two more bacteria, spherical forms which are connected in chains or develop in spontaneous directions. These are streptococci and staphylococci.

Streptococcus is abundant in the human microflora. When dividing these globular bacteria, they create beads or chains of microorganisms. Streptococci can cause infectious and inflammatory processes. Favorite places of localization are the oral cavity, the gastrointestinal tract, the genital organs and the mucosa of the respiratory tract.

Staphylococci are divided in many planes. They create grape clusters from bacterial cells. Are able to cause inflammation in any tissues and organs.

What conclusions should humanity make?

Man is too used to being the king of nature. Most often he leans only in front of 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 influence all biochemical processes. Clever people have long understood that "small" does not mean "useless" or "safe." Without bacteria, life on Earth will simply stop. And without an attentive attitude towards pathogenic bacteria - will lose quality and gradually die out.