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Difference Between Archaea and Bacteria


Stuck in understanding the difference between archaea and bacteria? Despite being prokaryotic microorganisms, there are specific differences between the two, which confuses most of us. So today, we will explicitly talk about archaea and bacteria in detail.

Archaea are thought to be the most ancient prokaryote, which emerged around a hundred years ago. Earlier in history, these were enlisted as a type of bacteria but later given the title “archaebacteria.” Scientists took this step, keeping in view the distinguishing characteristics of the organism that are mostly associated with a eukaryote. On the other hand, bacteria are a group of single-celled prokaryotes, present almost everywhere, around us, and on us. Let’s grab a quick comparison chart to know more about the two!

Comparison Chart

Basis of ComparisonArchaeaBacteria
Composition of Cell WallPseudo-peptidoglycan or glycoprotein cell wallPeptidoglycan (also known as murein)
Type of Cell MembraneLipid monolayer/bilayerLipid bilayer
Membrane LipidsPhytanyl glycerol ethersFatty acids, glycerol ethers
Main tRNAMethionineFormyl-methionine
Number of DNA PolymeraseMultipleSingle
TypesMethanogens, Halophiles, and ThermoacidophilesGram-positive bacteria & gram-negative bacteria
PathogenicityThese organisms are non-pathogenicBacteria can be pathogenic or non-pathogenic
ExamplesSulfolobus acidocaldarius, Staphylothermus marinus, Pyrolobus fumarii, etc.Escherichia coli, Staphylococcus aureus, and Lactobacillus acidophilus, etc.

Archaea – Brief Explanation

These are the unicellular prokaryotes, entirely different from bacteria and eukaryotes. An archaeon utilizes several energy sources to meet its needs. These organisms either rely on ATP or carbon compounds to gain nutrition. The group of archaea using sunlight to prepare their food are called phototrophs. While in contrast, archaea using ammonia and sulfur (inorganic substances) fall in the second category to release ATP. This process is quite similar to those occurring in eukaryotes. Thus, archaea somehow relate to multicellular organisms in their characteristics.

They differ in size, ranging from 0.5 to 4 µ, and have bacteria-like shapes, such as rods, spirals, and spheres. Archaea possess the cell wall, made up of pseudo peptidoglycans.


Bacteria – Brief Explanation

Bacteria or eubacteria are unicellular living bodies that lack a distinct nucleus and membrane-bounded organelles like mitochondria and chloroplast other organelles. All bacterial cells have a boundary that not only supports but also protects and monitors the cell material. The cell wall of bacteria is nothing but peptidoglycan, which plays a role in shielding the cell from external factors. Moreover, all the bacterial reactions occur in the cytosol of cytoplasm, where some ribosomes and chromatin material help in replication.

Not only this but there are numerous processes by which the bacteria divide. It can reproduce by budding, binary fission, and also fragmentation. Furthermore, transferring of hereditary material can also take place through conjugation, transduction, and transformation.


Catch the Differences Between Archaea and Bacteria



An archaeon is a unicellular body that lacks membrane-bounded organelles. Despite being a prokaryote, this organism follows eukaryotes in the replication of DNA.


Bacteria are the simple prokaryotes that live everywhere around us and are advantageous in many ways. Most bacteria are, nowadays, used by industries for human benefits.

Composition of Cell Wall


These organisms have ether bonding, so the cell wall is composed of pseudo-peptidoglycans.


Bacteria have a lipid bilayer that interlinks fatty acids and ester bonds. All bacterial cell walls are made up of peptidoglycans called murein.

Found In


Most archaea are present in peculiar environments, such as salt brines, ocean depths and hot springs, etc.


Most bacteria live underwater, in soil, in the air, and in living or non-living bodies.



There are generally three types of archaea, called halophiles, methanogens, and thermoacidophiles.


Bacteria are divided into two main types, called gram-positive and gram-negative bacteria.

Reproduction Method


As prokaryotes, they can reproduce asexually through fragmentation, binary fission, budding, etc.


Bacteria can either reproduce sexually or asexually. But the most favorable method of bacterial reproduction is through binary fission. It can also survive adverse conditions through spore formation.

Genetic Features


These organisms lack thymine in the transferase RNA but contain introns and exons.


These unicellular organisms lack introns but contain thymine in the transferase RNA.

RNA Polymerase



These complex living bodies contain ten subunits of an RNA polymerase.


A bacterial cell has comparatively more mere RNA polymerase with four subunits.



A few of many archaeon examples include Sulfolobus acidocaldarius, Staphylothermus marinus, Pyrolobus fumarii, etc.


There are hundreds and thousands of bacteria present in our environment. These consist of Escherichia coli, Staphylococcus aureus, Staphylococcus pneumoniae, and Lactobacillus acidophilus, etc.

Reach a Verdict

After reading the article above, now you must know about the difference between archaea and bacteria. Despite existing as prokaryotes, they have distinct characteristics. The hydrophobic part of a bacterial cell membrane is a fatty acid, while for archaea, it is phytanyl. Furthermore, an archaeon cell wall is pseudo-peptidoglycans or glycoproteins, whereas it’s entirely peptidoglycan for bacteria.

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