Kingdom Archaebacteria (Microbiology)

General account, Ultrastructure, Nutrition , Reproduction + (types), and Economic importance of Archaebacteria.
DPG Degree college, Gurgaon

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 swim using one or more flagella 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) Parasites – get energy from living organisms. Saprophytes – get energy from dead decaying matter . some are autotrophic (make their own food) 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.

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