Archaebacteria, single-celled prokaryotes, lack nuclei and interior membranes, and exhibit diverse shapes while thriving in extreme environments due to unique cell wall and membrane structures. They reproduce asexually through methods like binary fission and play significant roles in ecological systems and biotechnological applications, such as biogas production. These organisms can be autotrophic or heterotrophic, acquiring nutrients from a variety of sources, including chemicals and decaying matter.

1. ARCHAEBACTERIA
By
NISHA KATARIA

2. ARCHAEBACTERIA
Archaea = single-celled
organisms
 lack cell nuclei (prokaryotes).
 lack interior membranes and organelles.
 Size range from 0.1 (μm) to 15 μm in
diameter,
 occur in various shapes, commonly as
spheres, rods, spirals or plates.
 Membrane bounded by a cell wall and they
General Account

3. ULTRASTRUCTURE
 Archaea are prokaryotes, which
means that the cells don't have a
nucleus or other membrane-
bound organelles in their cells.
 have a coiled ring of DNA, and
 the cell cytoplasm contains
ribosomes for the production of
cell proteins.
 the cell wall and membrane give
the cell a specific shape such as
flat, rod-shaped or cubic.

4. Cell Wall
 archaea survive in varied
environments than other life
forms
 cell walls contain carbohydrates
that are different from those of
bacteria cell walls, and some
contain proteins and lipids to
give them strength and
resistance to chemicals.
cell membrane
 lies inside the cell wall and
controls the exchange of
substances between the cell
and its environment.
 archaea cell membrane is
made up of phospholipids with
fatty acid chains having ether
bonds.
 Ether bonds are more resistant
to chemical activity and allow
archaea cells to survive in
extreme environments.

5. Genes and Genetic
Information
 DNA is found in single circular
plasmids.
 the replication and translation
of DNA sequences takes place
as it does in eukaryotes.
Flagella
 flagella allow the archaea to
move.
 flagellum is a long stalk with
a base that can develop a
rotary action in conjunction
with the cell membrane.
 Flagella are useful in moving
cells toward food and in
spreading out after cell
division.

6. NUTRITION
How They Acquire Nutrients
• Some are heterotrophic (get food from another source)
i. Parasites – get energy from living organisms.
ii. Saprophytes – get energy from dead decaying matter.
•some are autotrophic (make their own food)
i. Photoautotrophs – use light energy and co2
•They can be chemotrophs, which means they make their own food from
chemicals around them(ammonia, and other nitrogen compounds).
What They Eat
Archaebacteria can eat hydrogen gas, carbon dioxide, and sulfur.
What Eats Them
Archaebacteria can be eaten by fungi and other bacteria.

7. REPRODUCTION
Archaea reproduce asexually by
• Binary or Multiple fission,
• Fragmentation, or
• Budding.
• Produce extracellular vesicles (EVs) which are
sometimes associated to filamentous structures
known as nanopods or nanotubes.
Budding

8. Reproduction (binary
fission)
 Archaebacteria reproduce
asexually through binary
fission.
 Binary fission is where the
circular DNA is copied and
the cell divide with each cell
having an identical copy of
DNA.

9. ECONOMIC IMPORTANCE
They are considered extremophiles which is
why they are so good for enzymes are proteins
which can function at extreme conditions.
 Archaebacteria known as Sulfolobus
acidocaldarius are known for their role in
bleaching purpose.
Methane gas is produced from the dung of
ruminants by the methanogens.

10. Methanogens are also involved in the
formation of biogas and sewage
treatment.
Archaebacteria are employed in the
production of gobar gas from dung and
sewage.
In ruminants, they cause fermentation
of cellulose.
ECONOMIC IMPORTANCE cont.