Extreme environments Flashcards
What are the two definitions of extreme environments
Anthropocentric: an environment which deviates significantly from conditions of temperature, pH or osmotic balance which are suitable for human life
Scientific: An environment where species diversity is very low, almost all are microorganisms
Examples of hypersaline environments
- Dead sea (34.2% salinity)
-Great Salt lake (5-27% salinity)
-Salterns - Salt flats
Dry lake beads
Salted food products
These environments are often also very hot and alkaline.
Examples of high temperature environments
- Hot spring in yellowstone park
- Hydrothermal vents
- Solfatara
- Fumaroles
Colouration in these regions are generated by minerals and organisms. Can show temperature zones
Examples of low temperature environments
- Snow pack Himalaya
- Polar regions
- Glaciers
- Deep ocean water
- Permafrost soil
Psychrophiles are the least studied group of extremophiles
Examples of acidic environments
- Acidic run-off yellowstone park
- Hoole bank acid tar lagoon, chester (former clay pit). Leptothrix discophora biofilm - are natural films. Not human contamination, produced by the organism
- Volcanic regions
- Mining areas
- Acidic tar lagoons
These habitats are often rich in Fe or S.
Examples of alkaline environments
- Lake Natron Africa
- Atacama desert
- Soda lakes
- Soils
- Mud volcanos
Magnetite-producing bacteria can create a desert varnish, a thin mineral precipitation
Examples of high pressure environments
- Mariana trench
- Ocean basins and deep water zones
- Oceanic trenches
- Earth crust up to 4km depth
The barophilic biomass has been suggested to exceed the biomass of all surface life.
Difficult to cultivate these bacteria
What’s the importance of extremophiles
a) a source of valuable natural products, including antioxidants, bio-stabilisers, compatible solutes, bio-surfactants, potential antibiotics, heat-stable enzymes, etc. Many of these products play or have the potential to play a role in sustainability efforts.
b) Important for our general understanding about the physiology and metabolism of cells
c) of great interest in the study of biodiversity on Earth, an individual extremophile group may be broadly dispersed around the phylogenetic tree of life.
d) important in the understanding of the origin and evolution of life on Earth.
e) important in the investigation of extra-terrestrial life, understanding the biology of extreme ecosystems on Earth will suggest locations for searching for life elsewhere in the Solar System.
