What are Eubacteria?

Mary McMahon
Mary McMahon

Eubacteria are microscopic single-celled organisms. They are sometimes referred to as the “true bacteria,” differentiating them from Archaebacteria, similar organisms with some significant genetic and lifestyle differences. The vast majority of organisms we think of as “bacteria” are Eubacteria, with their Archean cousins preferring extreme living environments like nuclear power plants and hydrothermal vents.

Eubacteria, also referred to as true bacteria, are the majority of what we think of as bacteria.
Eubacteria, also referred to as true bacteria, are the majority of what we think of as bacteria.

In order to delve into the definition of Eubacteria, it is first necessary to discuss a detail of scientific classification. These bacteria are at the heart of a serious debate in scientific classification which is reshaping the traditional hierarchy of “Kingdom, Phylum, Class, Order, Family, Genus, and Species.” Originally, Eubacteria were considered part of the Prokaryota kingdom, sometimes called “Monera,” along with their relatives the Archaebacteria.

Eubacteria are microscopic single-celled organisms.
Eubacteria are microscopic single-celled organisms.

Prokaryotic organisms like bacteria are primarily defined by their lack of cell nucleus. This makes them evolutionarily distinct from other living organisms, and has led to a number of innovative adaptations. Many prokaryotes are also single-celled, although this is not necessarily a requirement for membership in this kingdom. In addition to the Prokaryota kingdom, biologists also classified organisms into Animalia, Fungi, Plantae, and Protista.

In the 20th century, some people began to argue that Eubacteria and Archaebacteria should be considered two separate kingdoms, reflecting their considerable divergence. Therefore, some textbooks began to print a list of six kingdoms, rather than five. In 1990, the three-domain system was proposed, with researchers suggesting that a biological classification above “kingdom” needed to be created. In the three-domain system, organisms are classified as Eukaryota, Archaea (the new term for Archaebacteria), or Bacteria (the new title for Eubacteria).

Basically, the terms “Eubacteria” and “Bacteria” are interchangeable, since they both refer to a huge collection of organisms found everywhere on Earth, from the kitchen floor to mountain streams. However, some scientists prefer one term over the other, reflecting their position on scientific classification. The three-domain system is gaining considerable ground, so people may want to get used to calling “Eubacteria” by their new official title.

Bacteria are so diverse that it is extremely hard to make sweeping generalizations about this domain (or kingdom) of organisms, short of the statement that they are single-celled prokaryotic organisms. They come in a wide assortment of shapes, from neat rods to crazily twisted spirals, and they have a number of functions on Earth. Many people are familiar with bacteria in the form of organisms which cause disease, but bacteria are far more complex than that, and they are likely to endure on Earth long after other forms of life have vanished.

Mary McMahon
Mary McMahon

Ever since she began contributing to the site several years ago, Mary has embraced the exciting challenge of being a wiseGEEK researcher and writer. Mary has a liberal arts degree from Goddard College and spends her free time reading, cooking, and exploring the great outdoors.

You might also Like

Readers Also Love

Discussion Comments


Eubacterias are not eukaryotic. They do not have a nucleus.


Eubacteria are single-celled. They often live in colonies.


What environments do they live in?


Archaebacteria are more like archaea, right? So eubacteria is more like bacteria.


What are two unique traits for organisms in the following kingdoms:

1.Kingdom Arhaebacteria

2.Kingdom Eubacteria


Whats the main difference between archae and eu bacteria?


Is a eubacteria single celled?


Is it autotroph or heterotroph?


Do they have a cell wall? If so, what is it made out of?


Eubacteria is prokaryotic. The difference between eubacteria and archaebacteria is that archaebacteria was around when the earth was still young and it can live in much harsher environments. Bacteria cannot.


eubacteria is eukaryotic.


So are Eubacteria prokaryotic or eukaryotic?


@anon20136, Archaebacteria is the bacteria that lives only in extreme environments, like in nuclear plants, and the dead sea. Basically, archaebacteria can live only in places nothing else can live normally in. Eubacteria is every other kind of bacteria.


that's the exact question i'm asking.! lol


what is the difference of the eubacteria and the archaebacteria?

Post your comments
Forgot password?