Tag: archaebacteria

Peptidoglycan is a polymer that is present in the cell wall of most bacteria. It is also called as Murein. However, Archaebacteria are devoid of peptidoglycan in its wall. Instead, they are made up of the polysaccharide called pseudomurein.

Halophiles are organisms that grow in high salt concentrations. They are also called as salt-loving microorganisms. They are found in hypersaline environments like in arid, coastal, deep‐sea, underground salt mines. They can comfortably live in evaporation ponds or salt lakes due to the accumulation of KCl. By accumulating KCl, they maintain the osmotic balance. 

Peptidoglycan is a polymer that is present in the cell wall of most bacteria. It is also called as Murein. However, Archaebacteria are devoid of peptidoglycan in its wall. Instead, they are made up of the polysaccharide called pseudomurein. Arachebacteria consists of 3 groups, namely halophiles, thermophiles and methanogens. 

Archaebacteria are a type of single-cell organism which do not have membrane-bound organelles. They also lack true nucleus. They live in some of the harshest habitats. They have cell wall which is made up of polysaccharides and proteins without peptidoglycan. They include Methanogens, halophiles, thermophiles. Methanogens produce methane gas or biogas. They are present in the gut of several ruminant animals. Halophiles are present in areas with high salt concentrations. Thermophiles are present in areas with extremely high temperature.

Halophiles are organisms that thrive in high salt concentrations. They are also called salt-loving microorganisms. They are found in hypersaline environments like in arid, coastal, deep‐sea, underground salt mines. They can comfortably live in evaporation ponds or salt lakes such as Great Salt Lake, Owens Lake and the Dead Sea. They cannot live in less than 3M NaCl concentration. The concentration higher than 3M NaCl in the environment will cause movement of water outside from a plant cell to the environment and cell will die due to osmotic stress. A concentration of less than 3M NaCl concentration in the environment will cause the movement of water inside the cell from the environment will cause the cell to burst and the plant will die.

Thermococcus, Methanococcus and Methanobacterium are Archaebacteria. They lack histones. They have negatively supercoiled DNA. They differ from bacteria in a way that they survive extreme conditions. Unlike bacteria, archaea cell walls do not contain peptidoglycan. 

Archaebacteria differ from other bacteria in having a different cell wall structure and this feature is responsible for their survival in extreme conditions.

Methanogens belong to archaebacteria. They are strict anaerobes. They are autotrophs which obtain both energy and carbon from decomposition products. They occur in marshy areas where they convert formic acid and carbon dioxide into methane with the help of hydrogen. This capability is commercially exploited in the production of methane and fuel gas inside gobar gas plants, e.g., Methanobacterium, Methanococcus. Some of the methanogens live as symbionts inside rumen of herbivorous animals that chew their cud. These archaebacteria are helpful to the ruminants in fermentation of celullose.

Trypanosoma parasites cause sleeping sickness or African trypanosomiasis or Chagas disease which is found in sub-Saharan Africa.

Nitrogen fixing is seen in heterotrophic bacteria live in the soil and fix significant levels of nitrogen, species like Clostridium, Bacillus, Azotobacter are called nitrogen-fixing bacteria.