Types of Extremophiles | Biology Ideas | Types and Examples

Extremophiles can be divided into two categories

Here we are going to study some Types of Extremophiles…

  1. Extremophilic organisms that require one or more extreme conditions to survive.
  2. Extremotolerant organisms can tolerate extreme conditions of one or more physical parameters even though they grow optimally at neutral conditions. Extremophiles include members of all three domains of life; bacteria, archaea, and eukarya.


These are classified according to the conditions in which they grow –

Thermophiles – Organisms growing at high temperatures.

Hyperthermophiles – Organisms growing at very high temperatures.

Psychrophiles – Organisms that grow at low temperatures.

Acidophiles – Organisms thriving in habitats with an acidic PH.

Alkaliphiles – Organisms thriving in habitats with basic PH.

Halophiles – Organisms that grow well in an environment with NaCl.

Radoduric – Organisms that grow well in the presence of high radiation.

Barophiles – Organisms that grow best under pressure.


Types of Extremophiles


  1. Psychrophiles, literally meaning cold-loving.
  2. They are organisms adapted to growth at low temperatures.
  3. Having an optimum growth temperature of greater than 15°C and a maximum growth temperature of greater than 20°C and a minimum of 0°C.



  1. Thermophiles (lovers of true heat) are organisms that grow at temperatures higher than those (25-40 ° C) that support many species.
  2. Typically, a thermophile shows maximum growth rates at temperatures above 45°C.



  1. Hyperthermophiles are organisms that can survive and grow at extremely high temperatures (above 80°C).
  2. Hypothermophiles are a type of thermophiles that can endure even higher temperatures than other thermophiles.
  3. The optimum temperature of growth for hyperthermophiles is 80°C, but they can survive at temperatures higher than 100°C.



  1. Acidophiles are organisms that can survive and thrive in highly acidic conditions (usually at pH 2.0).
  2. Acidophilic microorganisms thrive in very low pH and man-made natural environments such as acidic lakes, other hydrothermal systems, acid sulfate soils, sulfidic regoliths, ores, and areas affected by iron and coal mines.



  1. Alkaliphiles are a group of extremophiles that can live and thrive in environments with extremely high pH values (9-13) with the optimal pH being 10.
  2. Alkaliphiles are of two types; obligate alkaliphiles growing only in environments with pH higher than 9 and facultative alkaliphiles that can live both at neutral pH and alkaline conditions.



  1. Halophiles are a group of extremophiles that require high salt concentrations for their survival and growth.
  2. Halophiles are of two types; obligate halophiles that require NaCl concentration of 3% or more and halotolerant that survive at both average salt concentrations and higher.



  1. Metallotolearnt microorganisms are microorganisms that are capable of tolerating and detoxifying high levels of dissolved heavy metals.
  2. Most metallotolerant microorganisms tend to be acidophilic as the physiological activities of such microorganisms enable tolerance against high metal concentrations.



  1. Radiophiles are a group of extremophiles that are capable of surviving extreme forms of radiations like ionizing radiant (gamma rays) and UV radiation.
  2. Studies on radiophiles are quite limited as they are to be isolated from extreme environments like outer space of other planets.

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