Archaebacteria: Definition, Characteristics, Types, Nutrition, and, Respiration

Archaebacteria: Definition, Characteristics, Types, Nutrition, and, Respiration

 Archaebacteria: Definition

The word  Archaea comes from the Ancient Greek word meaning ancient things. the first observed archaea were living in harsh environments such as hot springs and salt lakes. Archaea are found in almost every habitat, including soils, oceans, and marshlands. They are found in the gut, mouth, and skin. these are old bacteria. These are the organisms when the first life originated. these are the first organisms as they are capable of surviving in extreme conditions e,g in hot conditions at almost 100 degrees, highly acidic conditions i.e. high PH and high salt areas.

Archaebacteria Characteristics

Archaebacteria have several characteristics

1. the Archaebacteria are primitive from an evolutionary point of view

2. they are considered the oldest living fossils

3. the Archaebacteria are prokaryotic organisms

4. Archaebacteria have cell membranes made up of branched lipids and hydrocarbons.

5. their cell wall is made up of complex polysaccharides and complex polypeptides.

6. the nucleoid is present

7. Peptidoglycan is absent in the cell wall of Archaebacteria.

8. Mostly behave as obligate anaerobes i.e oxygen is a poison to these bacteria.

Types of  Archaebacteria

1. Methanogens, 2. Halophiles 3. Thermoacidophiles

1. Methanogens: the methanogens are obligate anaerobes. In biogas fermenters these bacteria produce methane. they can utilize CO2, and formic acid, after utilizing, they result in the formation of methane gas. this feature of archaebacteria is utilized for the formation of methane-rich fuel i.e biogas. some methanogens are Methanobacteria and Methanococcus.

Habitat: They are present in swampy areas, and marshy areas, in these areas water in the soil is more. Due to this reason space that should be filled with air is filled with water, thus we can say that air is absent in the soil, due to which there is an anaerobic condition. they also show association with cattle rumen.in cattle rumen, these are involved in cellulose digestion.

Nutrition: they can synthesize their food. So they are autotrophs. For the synthesis of food they don’t use light energy, they use chemical energy which is why they are known as chemoautotrophs, they show a chemoautotrophic mode of nutrition.

Respiration: in the case of methanogens they survive in anaerobic conditions i.e. They can survive in the lack of oxygen. they are obligate anaerobes.

2. Halophiles: Halophiles are salt-loving bacteria. They have been discovered to reside in areas with extremely high salt concentrations.

Habitat: they are present in areas where the salt concentration is high. they are present in tidal pools, and salt lakes. if we place halophiles in the salt medium they can be grown in a nutrient medium that contains 25-30% of Nacl salt concentration.

Nutrition: They are heterotrophic in nutrition, they are dependent on others for their food source so they are chemo organotrophs.

Respiration: they are facultative anaerobes

In the presence of light, these bacteria synthesize one pigment in the plasma membrane. the pigment which is synthesized is reddish-purple this is known as bacterial Rhodopsin. After absorbing light energy the pigment converts light energy into chemical energy forming ATP. Now this ATP is used by the bacteria for metabolic activities. but this ATP is not utilized for CO2 fixation or food synthesis. But these bacteria can utilize light energy. so this process of utilization of energy. so this process of utilization of light is known as phototrophy e,g Halobacterium, Halococcus.

3. Thermoacidophiles

They are found in sulphur springs. They can survive high temperatures as high as 110 degrees they can also survive in low PH acidic conditions as low as 2 degrees. thermoacidophiles in the presence of oxygen convert sulphur into sulphuric acid. In absence of oxygen, they convert sulphur into hydrogen sulphide.

Habitat: they are present in hot water springs

Nutrition: they are chemoautotrophs

Respiration: they are facultative anaerobes

Frequently Asked Questions about Archaea Bacteria

Question 1. What does Archaea mean?

ANS: The word archaea comes from the Greek word archaea, which means “ancient.”

Question 2. What is the distinction between archaebacteria and eubacteria bacteria?

ANS: Ancient bacteria are known as archaebacteria, whereas real bacteria are known as eubacteria. Archaebacteria, unlike eubacteria, can thrive in harsh environments.

Question 3. Are archaebacteria eukaryotic or prokaryotic?

ANS: Archaea are prokaryotic organisms that lack a nuclear membrane but have biochemistry and RNA markers that distinguish them from bacteria. Because of their complicated, unusual metabolisms, the Archaeans have a unique, ancient evolutionary history, making them some of the world’s earliest forms of life.