UNDERSTANDING MONERA: Eubacteria or Bacteria

Bacteria or eubacteria have characteristics that may be the same and / or different from archaebacteria or archae. Characteristics of bacteria or eubacteria, which are as follows. First , bacteria are single-celled or unicellular organisms.

Second , the bacterial cell nucleus does not have a nucleus or prokaryotic membrane. Third , the size of bacterial cells ranges from 1 – 5 µm, where every 1 μm is equal to 1/1000 mm.

Fourth , bacteria move with flagella or pili. Fifth , several types of bacteria play an important role in the process of decomposition of organic substances. Sixth , bacteria live in various environments or habitats. Seventh , bacteria reproduce asexually by dividing themselves.

After understanding about the characteristics of bacteria or eubacteria, the following will be explained about the structure of bacteria or eubacteria below.

Structure of Bacteria or Eubacteria

Bacteria or eubacteria have a structure. The structure of this bacterium consists of the outer structure of the cell, the inner structure of the cell, flagella, and pili or fimbriae. The explanation of each bacterial structure is as follows.

The outside structure of the cell. The outer structure of the bacterial cell consists of cell walls, capsules, and plasma membranes. The parts have their respective functions. Cytoplasmic membrane consists of a layer of lipoproteins or phospholipids and proteins that have permeable properties.

This cytoplasmic membrane acts to regulate the entry and exit of substances – substances that are in bacterial cells. Cell wall, has a function to protect and give shape to bacterial cells. This cell wall consists of hemicellulose and peptidoglycan compounds. This compound consists of protein and amino acids.

The capsule is the outermost part. This capsule is a mucous layer. Capsules have a function for cell protectors. In addition, it can be used for food reserves. The picture of the structure of bacteria or eubacteria is as follows:

The inner structure of cells. The inner structure of bacterial cells consists of DNA, mesosomes, plasmids, ribosomes, and endospores. The explanation of each of these sections can be explained as follows.

The mesosome is a part of the cytoplasmic membrane that experiences folding. This mesosome plays a role in cell wall synthesis and in the division of the nucleus or cell nucleus. DNA is part of the genetic material. This DNA as a carrier of nature in living things, especially bacteria.

Endospores are spores or structures that have thick walls. This thick wall is formed when environmental conditions are unfavorable to bacteria. Unfavorable environmental conditions, such as heat, cold, and dry.

Endospores will return to bacterial cells when environmental conditions begin to improve. This plasmid is shaped like a ring. Plasmids are found inside the cytoplasm. This plasmid serves as a means of cell defense against extreme environmental conditions.

Ribosomes form a part of cell organelles that have a major role in the process of protein synthesis that is inside the cell.

Flagella. Flagella is a bacterial locomotion. This flagella has a shape like a hair and is composed of a protein compound called flagelin. The number and location of flagella is one of the bases in the classification of bacteria.

Pili or fimbriae. This pili has a shape like a filament yarn. Pili is only owned by gram-negative bacteria. Pili size is smaller, shorter, and more than flagella. Pili has no function as a means of movement. However, pili has a function as a gateway for the entry of genetic material during the process of conjugation.

After understanding about the structure of bacteria. Where bacteria have four structures with their respective functions. Next will be explained about the classification of bacteria.

Also learn:  Understanding Growth and Germination in Plants

Classification of Bacteria or Eubacteria

Bacterial classification is done in several ways based on the location of the flagella on bacterial cells. Then, based on the shape of the bacterial body. Third, based on gram staining. Fourth, based on oxygen requirements. Fifth, based on the way of life.

Sixth, based on division within phyla or division. Each classification of these bacteria has a different meaning. The explanation of each classification of bacteria can be explained as follows.

Bacterial classification is based on the location of the flagella in bacterial cells. This classification is divided into four, namely monotrik, lopotrik, amfitrik, and peritrik. Each can be explained as follows.

Lopotrik is a bacterium that has two or more flagella. Which is located at one end of the cell. Amfitrik is a bacterium that has two or more flagella located at both ends of the cell.

Monotrics are bacteria that only have one flagella at one end of the cell. Peritrik is a bacterium that has flagella that are located throughout its cell surface.

Classification of bacteria based on the shape of the bacterial body. This classification is divided into four parts, namely vibrio or coma, spirilum or spiral, basil or stem, and cocci or round. The explanation of each part is as follows.

Vibrio or coma for example in bacteria Vibrio cholerae is a bacterium that can cause cholera. Spirilum or spiral, for example in the bacterium Trponema palidum.

Basil, or stem, is a monobacilli such as E. coli, Salmonella thypi and streptobacillus consisting of Azotobacter and Bacillus antracis bacteria.

Coccus or round are streptococci like S. thermophillus bacteria, diplococci like D. pneumoniae bacteria, and staphylococci like S. Aureus bacteria.

Bacterial classification based on gram staining. This gram coloring has a purpose. Gram staining test carried out by these bacteria is used to determine differences in the structure of cell walls.

There are two types of bacteria that are based on differences in gram staining, namely gram positive bacteria and gram negative bacteria. The explanation of each gram stain can be explained as follows.

First, gram-positive bacteria. This gram-positive bacteria give a purple color to the gram painting. This is due to the thick peptidoglycan wall. Furthermore, these gram-positive bacteria have simpler cell walls.

Even so, gram-positive bacteria are more about than cell walls of gram-negative bacteria. The thickness of gram-positive bacteria is around 20-25 nm. The examples of gram-positive bacteria are Aerococcus , Leuconostoc .

Second, gram-negative bacteria. These gram-negative bacteria have a thinner cell wall bacteria compared to gram-positive bacteria. The thickness of the cell wall of gram-negative bacteria is around 10-15 nm.

These gram-negative bacteria have fewer peptidoglycan contents. However, gram-negative bacteria have a more complex structure. Furthermore, gram-negative bacteria can give a red stain when gram stain is tested.

The red color is caused by thin peptidoglycan walls. Then, these gram-negative bacterial cells are coated by the periplasm and the outer membrane of the lipoprotein. In general, this type of gram-negative bacteria are bacteria that have pathogenic properties. As an example of the gram-negative bacterium that is E . coli, Shigella, Salmonella tyhi, and Enterobacter cloacae .

The classification of bacteria is based on oxygen requirements. This classification is divided into five types, namely obligate aerobic bacteria, facultative anaerobic bacteria, obligate anaerobic bacteria, aerotolerant anaerobic bacteria, and microaerophilic bacteria. Where each bacterium can be explained as follows.

First , microaerophilic bacteria are a type of bacteria that use oxygen for respiration. However, it can only live with low oxygen concentrations. An example of a microaerophilic bacterium, namely Campylobacter fetus, is a bacterium that can cause spontaneous abortions in farm animals.

Second , obligate aerobic bacteria are a group of bacteria that need oxygen gas in the process of respiration. Examples of obligate aerobic bacteria are Acitenobacter baumanii, which is a bacterium that can cause respiratory tract infections.

Third , obligate anaerobic bacteria are bacteria that do not need oxygen gas. This is because it can damage the bacterial cells. Examples of obligate anaerobic bacteria, Clostridium tetani, are bacteria that can cause tetanus.

Fourth , facultative anaerobic bacteria are bacteria that need oxygen gas. Even so, these bacteria can still live without having to use oxygen. Examples of facultative anaerobic bacteria are Escherichia coli where these bacteria can be found in the human intestine.

Fifth , aerotoleran anaerobic bacteria, is a bacterium that does not use oxygen. Even so, it can still live in a place that contains oxygen. Examples of aerotolerant anaerobic bacteria are Lactobacillus bulgarius and Streptococcus lactis which can be used in the yogurt and cheese industry.

The classification of bacteria is based on the way of life. This type of classification can be divided into two, namely autotrophic bacteria and heterotrophic bacteria. Each is still distinguished again, which can be spelled out in the explanation below.

First , autotrophic bacteria are a type of bacteria that can synthesize their own food from inorganic substances into organic substances. These autotrophic bacteria are divided into two, namely photoautotrophic bacteria and chemoautotrophic bacteria. Each can be explained as follows.

This photoautotrophic bacteria get an energy source for the process of food synthesis from light or through photosynthesis. Examples of photoautotrophic bacteria are green sulfur bacteria or chlorobium, cyanobacteria or Anabaena, and purple sulfur bacteria or Chromatium.

Chemoautotrophic bacteria are bacteria that use chemical compounds as an energy source used for the synthesis of organic compounds. Examples of chemoautotrophic bacteria are nitrifying bacteria ( Nitrosomonas and Nitrobacter ) and Thiobacillus .

Second , heterotrophic bacteria is a bacterium that cannot synthesize its own food. This bacterium utilizes organic material from other organisms. Heterotrophic bacteria are divided into two, namely parasites and saprophytes. Each of them can be explained below.

Saprofit is a bacterium that obtains food from the remains of organisms that have died. These dead organisms are like dead animals and organic waste. An example of saprophyte is E. coli.

A parasite is a bacterium that takes food from other organisms or its host. This can harm the host. An example of a parasite is Mycobacterium tuberculosis.

Bacterial classification is based on division in phyla or division. This classification is divided into five phyla, namely proteobacteria, gram-positive bacteria, spirochetes, chlamydias, and cyanobacteria or green-blue algae. Each of them can be explained below.

Cyanobacteria or green-blue algae are a group that contains several kinds of pigments. These pigments such as chlorophyll or green pigments, phycocyanin or blue pigments, carotenoids or orange pigments, and some additional pigments that can cause it to become colorful.

This chlorophyll pigment can make bacteria able to carry out a process of photosynthesis. The examples of cyanobacteria are as follows:

  1. Green-blue algae in the form of threads or filaments, for example Nostic, Oscillatoria, Anabaena.
  2. Green-blue single-celled algae, for example Gleocapsa, Chroococcus.
  3. Green-blue algae form a colony, for example Polycyshis.

Chlamydias are a group of bacteria that have the smallest size. Chlamydias can only live as parasites for the cells of other living things. An example of Chlamydias is Chlamydia psittaci where this bacterium can cause eye infections.

Spirochetes. This group of Spirochetes is not a large group. Nevertheless, the existence of the Spirochetes group can affect human life.

This is due to several types of bacteria that can cause disease in humans. An example of Spirochetes is Treponema pallidium in which this bacterium can cause syphilis.

Proteobacteria are the largest group of bacteria. Proteobacteria themselves are classified into purple bacteria which have photoautotrophic properties, preteobacteria kemoheterotrof and proteobacteria chemoautotrophs. Examples of Proteobacteria are Escherichia coli bacteria.

Gram-positive bacteria where in this group of gram-positive bacteria, there are some bacteria that can carry out photosynthesis or photoautotrophs.

However, some are chemoheterotrophic, and some form endospores (which are heat-resistant structures) when the environment has little food. Examples of gram-positive bacteria are Bacillus sp. and Clostridium sp.

After learning about the procedures for classifying bacteria which are divided into six ways. Next, it is explained about bacterial reproduction.

Bacterial Reproduction or Eubacteria

Bacteria reproduce in two ways, namely asexual reproduction and sexual reproduction. Each reproduction, both asexual and sexual, can be explained as follows.

  • Asexual or unmarried reproduction. This reproduction is done by dividing themselves in binary.
  • Sexual reproduction or marriage. This reproduction can occur in three ways, namely conjugation, transformation, and transduction. Each method in sexual reproduction or marriage can be explained as follows.

Transduction is a process of transfer of genetic material or DNA through an intermediary or viral infection.

Transformation is the transfer of one gene or bacterial DNA to another bacterial cell through a physiological process.

Conjugation is a method of reproduction by transferring genetic material through direct contact between bacteria.

Thus the explanation of the two processes of bacterial reproduction, both sexually and asexually. Next will be explained about the role of bacteria.

The Role of Bacteria or Eubacteria in Human Life

As with other organisms, bacteria also have a role in human life. The role that bacteria have in human life can be beneficial, but also can be detrimental. Each role will be explained below.

Beneficial bacteria. These beneficial bacteria are divided into nitrogen-fixing bacteria in plants, nitrifying bacteria, antibiotic-producing bacteria, and bacteria in the food industry. Further explanation about this bacterium is as follows.

First, nitrogen-fixing bacteria in plants. Some bacteria that play a role to bind nitrogen from free air, namely Azetobacter vinelandii, Clostridium pasteurianum, and Rhizobium leguminosarum which do symbiosis with legumes.

The fixation reaction of N 2 can be explained as follows.


2N 2 + 6H 2 O → 4NH 3 + 3O 2


Second, nitrifying bacteria. Nitrosomonas and Nitrosococcus bacteria can carry out the process of nitrification by converting ammonia or NH3 to nitrite or NO2. Meanwhile, the Nitrobacter bacteria can convert nitrite or NO2 to nitrate or NO3.

The reaction can be explained as follows.


2NH 3 + 3O 2  → 2 HNO 2 + 2 H 2 O + energy


2HNO 2 + O 2 → 2 HNO 3 + energy


Third, antibiotic-producing bacteria. This bacterium consists of

  1. Streptomyces griseus bacteria type of antibiotic produced is Streptomycin,
  2. Streptomyces rimosus bacteria, the type of antibiotic produced is Teracyclin,
  3. Bacteria Streptomyces venezuelae type of antibiotic produced is Chloramphenicol.
  4. Streptomyces aureofaciens bacteria, the type of antibiotic produced is Aureomycin.
  5. The bacterium Bacillus polymixa type of antibiotic produced is Polimiksin.

Fourth, bacteria in the food industry. This bacterium consists of

  1. Lactobacillus bulgaricus bacteria, food products produced namely Yogurt.
  2. Acetobbacter xylinum bacteria, the food product produced is Nata de coco.
  3. Lactobacillus casei bacteria, food products produced namely Yakult.
  4. Bacteria Streptococcus lactis, food products produced namely butter.
  5. Bacteria Acetobbacter sp., Food products produced namely vinegar acid.

Harmful bacteria. These harmful bacteria consist of bacteria that cause disease in humans, bacteria that cause disease in livestock, and finally, bacteria that can cause disease in plants. Each is explained further, as follows.

First , the bacteria that can cause disease in humans, are as follows

  1. Clostridium tetani bacteria that can cause tetanus disease.
  2. Salmonella tphosa bacteria that can cause typhoid.
  3. Mycobacterium tuberculosis bacteria that can cause tuberculosis.
  4. Bacteria Diplococcus pneumoniae which can cause pneumonia.
  5. Shigella dysentriae bacteria that can cause dysentery or digestion.

Second , the bacteria that can cause disease in livestock, are as follows.

  1. The bacterium Bacillus anthracis which can cause anthrax in cattle.
  2. Cytophaga columnaris bacteria that can cause disease in fish.
  3. Streptococcus agalactia bacteria that can cause inflammation of cow’s breast disease.
  4. Actinomyces bovis bacteria that can cause swollen jaw disease in cattle.

Third , the bacteria that can cause disease in plants, are as follows.

  1. Xanthomonas oryzae bacteria that can cause disease to attack the shoots of rice stems.
  2. Xanthomonas campestris bacteria that can cause diseases attacking cabbage plants.
  3. Pseudomonas solenacearum bacteria that can cause wilted leaf disease in eggplant.
  4. Bacteria Erwinia amylovora which can cause rot disease in fruits.
  5. Xanthomonas citri bacteria that can cause necrosis in citrus.

After understanding about the benefits of bacteria for human life, both beneficial and detrimental. Next, will be explained about Archaebacteria. Archaebacteria is the second kingdom of bacteria which is also known as the Archae.

Archaebacteria or Archae

Like bacteria, Archaebacteria has the following characteristics. First, Archae is a one-celled organism. Secondly, the archae live in extreme environmental conditions. Third, the archae has a cell wall that does not contain peptidoglycan.

The fourth characteristic, cells in the archae do not have a nucleus or prokaryotic membrane, however the ribosome is similar to the eukaryotic ribosome. Fifth, the plasma membrane of the archae contains lipids. The last or sixth trait, the average archae has a size of 0, 1 µm – 15 µm.

After understanding the six characteristics of Archaebacteria or Archae. Next will be explained about the Archaebacteria group.

Archaebacteria or Archaeae

Archaebacteria or Archae consist of three groups, namely Metanobaceria, Halobacterium, and Thermoplasma. Each group can be explained as follows.

The first group , Thermoplasma. Thermoplasma is found in acidic water from hot sulfur springs.

The second group , Halobacterium. Halobacterium is a type of halophil that lives in extreme conditions with high salt content. Halobacterium can be found in the Dead Sea and Great Salt Lake.

The third group , Metanobacteria. Metanobacteria is a bacterium that is hemoautotrophic. Where Metanobacteria is capable of producing methane gas or CH 4 and does not require oxygen or anaerobes.

Examples of Metanobacteria are Succinomonas amylolytica bacteria that live in the digestive tract in cattle.

Friends of the science portal, do you understand about monera? As explained above, monera has two kingdoms, bacteria and archae. Archaebacteria or Archae and Bacteria or Eubacteria are single or single celled organisms.

In addition, bacteria and archae also do not have a core membrane. However, each kingdom, both bacteria and archae, also has different characteristics, such as the size of bacteria and archae.

Furthermore, the classification for bacteria and archae is also not the same. Where bacteria have six ways in classification, while archae has three ways in classification. As with other organisms, bacteria have beneficial and detrimental benefits to human life.

Even though it has adverse effects, bacteria are still needed for human life, especially good bacteria. One example in the food industry such as yakult and yogurt that we usually consume turns out to require bacteria in its manufacture.

Thus the friend of the portal of knowledge, our presentation of the material understanding of monera. Hopefully this article can help all of you to understand more about all matters relating to monera and its kingdom, namely bacteria and archae. Happy learning friends portal knowledge and success always.

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