Archaebacteria vs Eubacteria: Difference and Comparison

Archaebacteria and eubacteria are two different domains of the monera kingdom. Both of them are unicellular microorganisms and are commonly called prokaryotes.

Key Takeaways

1. Archaebacteria are known for their ability to live in extreme environments such as hot springs, while Eubacteria are commonly found in soil, water, and living organisms.
2. Archaebacteria have unique cell walls that lack peptidoglycan, while Eubacteria have cell walls containing peptidoglycan.
3. Archaebacteria play an essential role in the carbon and nitrogen cycles, while Eubacteria significantly impact human health and the environment.

Archaebacteria vs. Eubacteria

Archaebacteria, or Archaea, are single-celled microorganisms distinct from bacteria and eukaryotes. They thrive in extreme environments such as hot springs, salty lakes, and deep-sea vents. Eubacteria, or bacteria, are single-celled microorganisms, found almost everywhere on Earth in plenty of shapes and sizes.

Eubacteria, also known as “true bacteria,” are unicellular prokaryotic microorganisms in many different areas worldwide. They lack a membrane-bound nucleus, and their cell wall comprises peptidoglycans in a cross-linked chain pattern.

This structure helps them to maintain their shape and size. There are generally three types of eubacteria. They have various characteristics.  Archaebacteria, or the “ancient bacteria,” are also unicellular prokaryotic microorganisms.

They are generally found in ocean depths. They are capable of surviving in extreme environmental conditions. Archaebacteria are considered to be the modern form of some of the oldest bacteria found on Earth. 

Comparison Table

Parameters of Comparison	Eubacteria	Archaebacteria
Definition	Eubacteria, known as “true bacteria,” are unicellular prokaryotic microorganisms.	Archaebacteria are unicellular prokaryotic organisms.
Size	0.5 – 5 μm	0.1 – 15 μm
Habitat	These are everywhere, like soil, water, other organisms, etc.	These are commonly found in extreme environmental conditions.
Types	Three types: Gram-positive, Gram-negative, and Miscellaneous.	Three types: Crenarchoeta, Euryarcheota, and Koranchaeota
Cell wall	Made up of peptidoglycans with muramic acid.	Made up of pseudo peptidoglycans.

What is Eubacteria?

Eubacteria, or “true bacteria,” are unicellular prokaryotic microorganisms. They are found in different areas around the world. They live in soil, water, and even inside and on some other organisms.

All bacteria except the archaebacteria come under eubacteria. Since they are prokaryotic, they lack a membrane-bound nucleus. Their cell wall is generally made up of peptidoglycans in a cross-linked chain pattern.

This type of structure helps them to maintain their shapes and sizes. Eubacteria have a wide range of characteristics. Some bacteria have a flagellum, a structure made of proteins and often used for movements.

Some bacteria have pili which are small projects found on their bodies that help them to stick on a surface or to transfer DNA. Some bacteria are even capable of forming a biofilm, a structure with high antimicrobial resistance.

At certain unfavorable environmental conditions, eubacteria can survive by producing spores. It keeps them dominant over extreme conditions like high and low temperatures or acidic, basic conditions.

Eubacteria can reproduce through binary fission and budding. Eubacteria are classified into three types, i.e., Gram-positive, Gram-negative, and miscellaneous.

What is Archaebacteria?

Archaebacteria are unicellular prokaryotic organisms. Earlier, they were considered the same as all the other forms of bacteria. However, after some profound studies and research, scientists discovered that archaebacteria are way different than the usual modern forms of bacteria.

Archaebacteria have very different genetics and biochemical properties. They are considered the modern form of very ancient types of bacteria found on earth, and therefore they are named “archaebacteria,” where the word “archae” means ancient.

These bacteria can survive in extreme environmental conditions like high or low temperatures, salty habitats, acidic, basic conditions, etc. They are generally found in sulfate-rich ocean depths.

There are a lot of characteristics of archaebacteria that make them different from any other form of bacteria, like the unique cell membrane chemistry or the unique gene transcription, etc.

Archaebacteria are often classified into three different forms i.e.

1. Chrenarchoeta, these archaebacteria are capable of tolerating extreme heat.
2. Euryarchaeota, are capable of surviving in harsh salty habitats.
3. Koranchaeota is considered the oldest form of archaebacteria and still has much information to discover.

Main Differences Between Eubacteria and Archaebacteria

1. Archaebacteria have a simple organization of structure, whereas eubacteria have a complex system.
2. The cell walls of archaebacteria are made up of pseudo peptidoglycans, whereas eubacteria’s cell walls are made up of peptidoglycans with muramic acid.
3. Archaebacteria are found in extreme environmental conditions, whereas eubacteria are found everywhere.
4. Archaebacteria have three types, i.e., Crenarchoeta, Euryarchaeota, and Koranchaeota, while eubacteria are classified into three types, i.e., Gram-positive, Gram-negative, and Miscellaneous.
5. The size of archaebacteria is around 0.1 – 15 μm in diameter. At the same time, eubacteria are 0.5 – 5 μm in diameter.
6. Archaebacteria have an asexual mode of reproduction like binary fission and budding; however, eubacteria and binary fission and budding produce spores to stay dominant in extreme conditions.
7. Archaebacteria are found in the ocean’s depths; in contrast, eubacteria are found everywhere, like in soils and water; some are even found inside and on other organisms.

References

1. https://www.pnas.org/content/86/23/9355.short
2. https://link.springer.com/article/10.1007/BF00270794