Hyperthermophiles are organisms that grow and multiply at extremely high temperatures - over 60 ° C. The optimal temperature for the existence of hyperthermophiles is more than 80 ° C. Hyperthermophiles are a type of extremophile and include mainly organisms belonging to the Archaea domain ( lat. Archaea ), although some bacteria can also withstand temperatures exceeding 100 ° C. Many hyperthermophiles can also resist other extreme factors, such as high acidity or radiation .
Content
- 1 History
- 2 Research
- 3 cell structure
- 4 Some hyperthermophiles
- 5 notes
History
Hyperthermophiles were discovered in 1969 by Thomas D. Brock in the hot springs of Yellowstone National Park, Wyoming , USA . After that, more than 70 species were discovered. The most pronounced extremophiles to date have been found on the overheated walls of deep-sea hydrothermal springs, which, in order to survive, need at least a temperature of 90 ° C. An unusual heat-resistant hyperthermophile, recently discovered strain 121 [1] , could even double its population in 24 hours in an autoclave with a temperature of 121 ° C (hence the name). Currently, a record high temperature of 122 ° C is able to withstand the appearance of Methanopyrus kandleri , while remaining able to grow and reproduce.
Although no known thermophile lives at temperatures above 122 ° C, their existence is quite possible (strain 121 was kept at 130 ° C for 2 hours, but did not breed until it was transferred to fresh nutrient medium at a relatively cool temperature of 103 ° C) . However, it seems unlikely that microbes would survive at temperatures above 150 ° C, since DNA and other vital molecules are destroyed at this point.
Research
In early studies of hyperthermophiles, it was suggested that their genome may be characterized by a high GC ( guanine - cytosine ) composition, but recent studies have shown that “there is no clear link between the GC composition of the genome and the temperature optimal for growth” [2] [3] .
Protein molecules of hyperthermophiles exhibit hyperthermostability. Due to this, they can maintain structural stability (and hence functions) at high temperatures. Such proteins are homologous to their functional counterparts in organisms living at lower temperatures, but they are adapted to perform their functions at significantly higher temperatures. Most low-temperature homologues of hyperthermally stable proteins denature at temperatures above 60 ° C. Such hyperthermally stable proteins are often of industrial importance because they accelerate chemical reactions at high temperatures [4] .
Cell Structure
The cell membrane of hyperthermophiles contains many saturated fatty acids , usually forming a C 40 monolayer, which retains its shape at high temperatures.
Some Hyperthermophiles
- Methanopyrus kandleri , strain 116, an Archean from the Arabian-Indian ridge , lives and reproduces at 80–122 ° C
- Strain 121 , archaea from the Pacific , thrive at 121 ° C
- Pyrolobus fumarii , Archean, living at 113 ° C in the hydrothermal springs of the Atlantic Ocean
- Pyrococcus furiosus , Archean, lives and multiplies at 100 ° C, first discovered in Italy near a volcanic source
- Geothermobacterium ferrireducens , a bacterium that thrives at 65–100 ° C in Obsidian Pond, Yellowstone National Park
- Aquifex aeolicus , a bacterium, lives at 85–95 ° C, Yellowstone National Park
Notes
- ↑ Microbe from depths takes life to hottest known limit
- ↑ High guanine-cytosine content is not an adaptation to high temperature: a comparative analysis amongst prokaryotes
- ↑ Zheng H. , Wu H. Gene-centric association analysis for the correlation between the guanine-cytosine content levels and temperature range conditions of prokaryotic species (English) // BMC Bioinformatics : journal. - 2010 .-- December ( vol. 11 ). - P. S7 . - DOI : 10.1186 / 1471-2105-11-S11-S7 . - PMID 21172057 .
- ↑ "Analysis of Nanoarchaeum equitans genome and proteome composition: indications for hyperthermophilic and parasitic adaptation."