Table of Contents
Definition of Thermophiles
The term “thermophiles” refers to bacteria that can thrive in temperatures as high as 55°C (minimum 45°C, optimal temperature range 55–65°C, maximum 80°C). Hyper-thermophiles (extreme thermophiles) are microorganisms that can grow even at temperatures as high as 113°C, with 80°C being ideal.
Thermophiles include Bacillus stearothermophilus, Thermoplasma acidophilum, Thermus aquaticus, and others, whereas extreme thermophiles include Pyrodictium occultum and Pyrococcus abyssi.
Thermophiles often include archaea and bacteria (thermophilic prokaryotes), which can survive in high temperatures. The oldest known bacteria could be included as thermophilic eubacteria.
Thermophiles can be found in various geothermally heated areas of the Earth, including peat bogs, compost, deep sea hydrothermal vents, and hot springs like those at Yellowstone National Park.
The enzymes in thermophiles perform at high temperatures. Some of these enzymes, such as the Taq polymerase utilised in PCR, are employed in molecular biology.
Classification
Different categories can be used to classify thermophiles. These organisms can be classified in one way based on the temperatures at which they thrive best:
- Simple thermophiles: 122–147.2°F (50–64°C)
- Extreme thermophiles: 149–174.2°F (65–79°C)
- Hyperthermophiles: Can tolerate temperatures up to 80°C (176+ °F) but not below 50°C.
Thermophiles can be arranged in the following order in a related classification:
- Facultative thermophiles, also known as moderate thermophiles, may survive below 50°C (122°F) as well as at high temperatures.
- Obligate thermophiles, also known as extreme thermophiles, need high temperatures to survive.
- Hyperthermophiles are especially extreme thermophiles, with optimum temperatures over 80°C (176°F).
Examples
An extremophile, or an organism that enjoys extremes, is a thermophile. The Archaea Domain, which was not identified until the 1970s, is where most thermophiles reside. Other extremophiles like halophiles (salt-loving) and acidophiles (acid-loving) are members of the Archaea Domain.
Thermophiles live in some of the most hazardous settings on Earth because they prefer hot temperatures. They are capable of surviving in hot springs and also in hydrothermal vents found beneath the ocean. Gases, metals, and minerals present in these harsh settings are the only sources of sustenance for thermophiles.
Methanopyrus kandleri, a thermophile that can endure temperatures higher than 250°F, has been discovered by scientists. Among the methanogens, it currently holds the distinction of being the hottest thermophile.
Related Links:
- Bergey’s Classification of Bacteria
- Shapes of Bacteria
- Flashcards For NEET Biology – Biological Classification
Visit BYJU’S Biology for more information.
Frequently Asked Questions – FAQs
Mention the significance of enzymes from thermophiles.
Thermus aquaticus, a bacterium species found in surface aquatic environments like the hot springs in Yellowstone National Park, is the source of Taq DNA polymerase, the most widely used DNA polymerase for the PCR or polymerase chain reaction technique. The absence of Taq DNA polymerase proofreading is troublesome for some PCR applications.
Pyrococcus furiosus is a bacteria that produces another heat-resistant polymerase (Pfu). This species is a hyperthermophile since it thrives at temperatures above 100°C.
