The bacteria , besides providing some positive aspects in the proper functioning of ecosystems, may also cause a number of diseases dangerous to humans. Within this great kingdom of microorganisms are eubacteria, also known as true bacteria .


What are eubacteria?

Eubacteria are a type of prokaryotic organism that does not have a membrane-protected nucleus . They are unicellular beings that have DNA in a single circular chromosome and that, as long as it has a cell wall, they have peptidoglycan .

  • Definition
  • Characteristics of eubacteria
  • Domain
  • Which kingdom do they belong to
  • Types of eubacteria
  • Structure
  • Nutrition of eubacteria
  • Habitat
  • Function
  • Diseases
  • Importance
  • Examples of eubacteria


A eubacterium is a term used to describe and differentiate true bacteria from archaebacteria . They are a sub – kingdom of microorganisms that are characterized by being prokaryotic and that also do not have a cell wall but instead contain a peptidoglycan wall and an outer layer of lipoproteins . They are microscopic beings that do not have mitochondria or organelles and that also contain a single chromosome located outside the nucleus, which makes them reproduce asexually .


Characteristics of eubacteria

Eubacteria are characterized by not having an adequately defined nucleus or cell membrane . They are enclosed by a cell wall that gives it the strength to be able to constantly maintain its shape and size when faced with a series of changes in its environment. They have cholesterol in their membranes which allows them to have permeability and their plasma membrane is located inside the cell wall .

Some of them can be mobilized using flagella and some have pili , tiny projections located on the outside that give them the ability to join surfaces and thus transmit their DNA. They can be circular or also have a linear shape . They have a type of binary fission reproduction and for this, they must first take an elongated shape to later be able to separate.

When they manage to make an outbreak in the mother card, then two identical cells called daughters are formed. They have the ability to become endospores when external conditions do not help them to reproduce. They are able to tolerate very high or very low temperatures, live in acidic environments and also survive radiation. They can have different types of shapes, bacillus , coconut and spiril . The bacilli will have a rod-like shape, the cocci are more spherical in shape while the spirillae are spiral-like.


The domain in which eubacteria are located is that of Bacteria .

Which kingdom do they belong to

Eubacteria, because they are a type of bacteria, belong to the Monera Kingdom, which is considered the most primitive among all prokaryotic organisms and that also do not have a nucleus surrounded by some type of membrane or organelles.

Types of eubacteria

Eubacteria have several types and in total there are five different rows which are mentioned below:

  • Chlamydia that can cause different types of bacterial diseases in the human body.
  • Cyanobacteria or blue- green algae which live in aquatic environments and manage to obtain the energy they need thanks to the photosynthesis process.
  • Gram positive and gram negative bacteria.
  • Proteobacteria that form the second largest group of bacteria that exist.
  • Spirochetes that are characterized by being long, thin and some have a spiral shape. Many of them can cause serious illnesses like Lyme.

Depending on their shape they can be grouped into three different types. Cocci that are eubacteria that have a spherical or oval shape, such as streptococcus and staphylococcus. Many of them can cause poisoning problems when they are found in contaminated food and are ingested and in severe cases they can even cause toxic shock.

The bacilli are those that have a rod-shaped shape, many of them act as pathogens causing very serious diseases such as anthrax, bubonic plague and pneumonia. The spirochetes in turn, have a spiral shape and they can be found producing bacteria syphilis and leptospirosis. Some spirochetes are beneficial, such as those that inhabit the stomach of ruminants and termites.


The structure of eubacteria can vary considerably, they have a wall that provides protection and in some cases a viscous layer. Many of them also have flagella to move around and others have fimbriae or pili , which help them to attach to the host when they act as parasites. In its internal part they contain cytoplasm in which the DNA is also located . Its cytoplasm is composed mainly of water and also has a gelatinous consistency.

Nutrition of eubacteria

Most eubacteria are heterotrophic , in other words, they must get their food from totally external sources. Some of them also eat materials already dead and others are parasites, which means that feed on the body acting as host. Some of them, although in smaller quantities, are autotrophic and therefore can produce their food, either by photosynthesis or by chemosynthetic means .


By having a great variety of biochemical aspects, eubacteria have the ability to develop and live in practically all types of habitats that exist on Earth. Many of them also live as a type of parasite, lodging in the host’s body and causing disease.


Although many of them turn out to be harmful to humans and animals, eubacteria can play a very important role in the proper digestion of food and in the synthesis of vitamin K.  Some can even protect the body against other bacteria that do cause damage to the body.


Eubacteria have the ability to cause a large number of diseases, some of them can even be serious for humans and animals. Several pathologies such as tuberculosis , syphilis , bacterial meningitis , tetanus , some serious intestinal problems caused by salmonella, bubonic plague , cholera , urinary tract infections, among others, can be caused due to the presence of eubacteria.


Eubacteria also help keep the environment free of nitrogen because they have the ability to fix it. They help in the production of lactic acid and even some vitamins such as riboflavin is composed of butyl Clostridium. Some of them are used with the aim of reducing environmental pollution as they can even degrade the different types of waste that result from the use of oil.

Examples of eubacteria

Two of the main examples of eubacteria are well known worldwide are:

  • Escherichia coli : This type of eubacterium also has a proteobacterial classification , is gram-negative and rod-shaped. It is common to find it inside the intestines of living beings, including humans. Some strains can cause food poisoning and other types of illnesses such as diarrhea.
  • Streptococcus pneumoniae : Its shape is like that of a coconut and it is gram-positive . It is normally found in the respiratory tract , the nasal cavity and the sinuses paranasal . This type of bacteria can become a pathogen causing serious health problems such as meningitis. It can also cause acute sinusitis and, in extreme degrees, sepsis.

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