Archaebacteria

Basic Information

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A subkingdom of bacteria, they survive in environments similar to those found on the young earth: hot springs, sea vents releasing sulfide-rich gases, boiling muds around volcanos, that sort of place. They differ from other bacteria (called Eubacteria) because:

they are mostly anaerobic
the RNA of their ribosomes is different to that of Eubacteria.
they have no peptidoglycan in their cell walls
their fats are linked together in a different way

They include the methane forming, the salt loving and the heat loving bacteria.

Methane Forming

The methanogenic bacteria create ATP by reducing carbon dioxide from the atmosphere using hydrogen, formate, methanol or other reduced molecules. As a result methane is liberated. This can only be done in the absence of free oxygen. So they are poisoned by normal air.

These bacteria live in marshes, when we call the methane they produce 'marsh gas'. They also thrive in sewage treatment plants and the intestines of animals.

Salt Loving

Before the invention of refrigeration and freezing, people used to preserve their food by salting it. This killed the bacteria. However there are some bacteria, the Halophilic bacteria, which can only live in water with a high salt concentration! They produce a pink scum on salt flats. They are aerobic.

Heat Loving

Another way to kill normal bacteria is to cook food. But heat does not kill some archaebacteria. Thermoacidophilic bacteria can only live in water which is very hot (70 - 75° C) and as acidic as concentrated sulphuric acid. They are found in hot springs.

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3.5 Billion Years ago

Biological Environment > Archaebacteria

Basic Information