how hyperthermophiles survive in high temperature

These organisms can even survive the autoclave, which is a machine designed to kill organisms through high temperature and pressure. Because hyperthermophiles live in such hot environments, they must have DNA, membrane, and enzyme modifications that help them withstand intense thermal energy.

Full Answer

How do thermophiles adapt to their environment?

We pay less attention to the currently known single molecular adaptations for thermophiles. Environmental changes such as temperature shifts induce genomic evolution, which in turn provides the bacteria with thermal-tolerant abilities to survive under high temperatures.

Why do hyperthermophiles live in such hot environments?

Because hyperthermophiles live in such hot environments, they must have DNA, membrane, and enzyme modifications that help them withstand intense thermal energy. Such modifications are currently being studied to better understand what allows an organism or protein to survive such harsh conditions.

How do hyperthermophiles survive the autoclave?

These organisms can even survive the autoclave, which is a machine designed to kill organisms through high temperature and pressure. Because hyperthermophiles live in such hot environments, they must have DNA, membrane, and enzyme modifications that help them withstand intense thermal energy.

What is the effect of pressure on hyperthermophiles?

Pressure effects on hyperthermophiles are generally favorable for growth at high temperatures. Relative to low pressures (0.1–3 MPa), the maximum growth temperature increases 2–6 °C for Pyrococcus, Thermococcus, and Desulfurococcus species when incubated at in situ pressures.

How do archaea survive extreme heat?

These organisms can even survive the autoclave, which is a machine designed to kill organisms through high temperature and pressure. Because hyperthermophiles live in such hot environments, they must have DNA, membrane, and enzyme modifications that help them withstand intense thermal energy.

What temperature do hyperthermophiles live?

Today, hyperthermophilic ('superheat-loving') bacteria and archaea are found within high-temperature environments, representing the upper temperature border of life. They grow optimally above 80°C and exhibit an upper temperature border of growth up to 113°C.

How do archaea survive in extreme conditions?

Scientists had known that this group of microbes – called archaea – were surrounded by a membrane made of different chemical components than those of bacteria, plants or animals. They had long hypothesized that it could be what provides protection in extreme habitats.

What adaptations do hyperthermophiles have?

Newly described adaptive features of hyperthermophiles include proteins whose structural integrity persists at temperatures up to 200 degrees C, and under elevated hydrostatic pressure, which in some cases adds significant increments of stability.

How can bacteria survive in high temperatures?

Environmental changes such as temperature shifts induce genomic evolution, which in turn provides the bacteria with thermal-tolerant abilities to survive under high temperatures. Such evolutionary changes could be achieved through horizontal gene transfer (HGT), gene loss, or gene mutations (4).

Can enzymes withstand high temperature?

Enzymes from these organisms (or hyperthermophilic enzymes) developed unique structure-function properties of high thermostability and optimal activity at temperatures above 70°C. Some of these enzymes are active at temperatures as high as 110°C and above (349).

What do archaea need to survive?

Archaea requires neither sunlight for photosynthesis as do plants, nor oxygen. Archaea absorbs CO2, N2, or H2S and gives off methane gas as a waste product the same way humans breathe in oxygen and breathe out carbon dioxide.

What archaea live in extreme environments?

thermophilesArchaea that live in salty environments are known as halophiles. Archaea that live in extremely hot environments are called thermophiles. Archaea that produce methane are called methanogens.

Do all archaea live in extreme environments?

Archaea is the main group to thrive in extreme environments. Although members of this group are generally less versatile than bacteria and eukaryotes, they are generally quite skilled in adapting to different extreme conditions, holding frequently extremophily records.

Which bacteria can tolerate high temperature?

Thermophiles can survive at high temperatures, whereas other bacteria or archaea would be damaged and sometimes killed if exposed to the same temperatures. The enzymes in thermophiles function at high temperatures.

What adaptations might archaea possess that allow them to survive in such extreme heat?

Archaea can be categorized into three groups on the basis of protein adaptations: thermophilic, psychrophilic, and halophilic. Thermophilic proteins tend to have a prominent hydrophobic core and increased electrostatic interactions to maintain activity at higher temperatures.

Why do some microorganisms tolerate higher temperature ranges than others?

Microorganisms thrive at a wide range of temperatures; they have colonized different natural environments and have adapted to extreme temperatures. Both extreme cold and hot temperatures require evolutionary adjustments to macromolecules and biological processes.

What bacteria can survive 100c?

Microorganisms that can grow at and above 100 degrees C were discovered a decade ago, and about 20 different genera are now known. These so-called hyperthermophiles are the most ancient of all extant life; all but two genera are classified as Archaea.

At what temperature do enzymes work best?

about 98.6 degrees FahrenheitThe optimum temperature for most enzymes is about 98.6 degrees Fahrenheit (37 degrees Celsius). There are also enzymes that work well at lower and higher temperatures.

What is the coldest place a cell can survive?

Scientists have pinpointed the lowest temperature at which simple life can live and grow. The study, published in PLoS One, reveals that below -20 °C, single-celled organisms dehydrate, sending them into a vitrified – glass-like – state during which they are unable to complete their life cycle.

What organism can survive the highest temperature?

WASHINGTON (AP) _ Some may like it hot, but nothing likes it hotter than a weird microbe known as Strain 121. The one-celled organism, captured from a magma vent at the bottom of the Pacific Ocean, can survive 266 degrees, a temperature no other known life form can tolerate.

What temperature do thermophiles grow at?

Thermophiles are referred to as microorganisms with optimal growth temperatures of >60°C. Over the past few years, a number of studies have been conducted regarding themophiles, especially using the omics strategies. This review provides a systematic view of the survival physiology of thermophiles from an “omics” perspective, ...

What is the best temperature for a microorganism to survive?

Generally, microorganisms with an optimal growth temperature (OGT) between 60 and 80°C are designated as thermophiles, whereas those growing optimally at temperatures of >80°C are referred to as hyperthermophiles, which are found in the three domains of life, archaea, bacteria, and eukarya, but the majority are archaea and bacteria. As we focus on the molecular basis of the adaption of micro-organisms at high temperatures but not the biological taxonomy, thermophiles vs. hyperthermophiles and bacteria vs. archaea are not specifically differentiated and are simply denoted as thermophiles in this review.

How does HGT affect the evolution of a genome?

HGT occurs in two ways: either the new sequence replaces the homologous sequence or the sequence is acquired through gene integration by transduction, conjugation, and transformation. A comparison of hundreds of sequenced genomes demonstrates that >20% of the bacterial genes and >40% of the archaeal genomes are horizontally transferred ( 32, 62, 67, 81 ). In the thermophilic bacteria Thermotoga maritima and Aquifex aeolicus, ∼24 and 16.2% of the genes were introduced from archaeal thermophiles by HGT ( 1, 60 ). Many of the HGT-acquired genes bestow thermophilic traits that are essential for survival under extreme conditions. One prominent example is reverse gyrase, which is considered a thermo-adaptation trait that was transferred from archaea to bacteria ( 29, 34 ). Reverse gyrase is a DNA topoisomerase that introduces positive supercoiling to increase the melting temperature of double-stranded DNA. Once the reverse gyrase gene was deleted from the chromosome of T. kodakarensis, the mutant strain grew slowly under high temperatures, demonstrating the critical contribution of reverse gyrase to thermophily ( 3, 65, 81 ). The presence of thermophilic traits in a thermophilic organism's genome that were transferred from other species indicates that HGT is effective in acquiring thermo-adaptive capacities. The contribution of horizontal gene transfer to the increased OGT in thermophiles was recently reviewed, and it was noted by Van Wolferen that thermophiles might not exist without gene exchanges among species ( 80 ).

What are the components of a thermophile?

The central elements of translational machinery include mainly tRNA, rRNA, and ribosomal proteins . As previously mentioned, the thermophile tRNA and rRNA with high GC contents are more stable than those of mesophiles. What about the protein components of the machinery? The proteomics analysis of Thermoanaerobacter tengcongensis suggested that the abundance of ribosomal protein S1 was significantly upregulated under higher temperatures than under the OGT ( 20 ). The proteomics study regarding a thermophilic bacterium Bacillus methanolicus MGA3 revealed the abundant increase of several ribosomal protein members, such as ribosomal protein L17, 50S ribosomal protein L14, and 30S ribosomal protein S18, in addition to the ribosomal-associated protein ribosome-binding factor A when the bacterium grow at higher temperature than the OGT ( 56 ). Another study integrated of proteome and transcriptome on Pyrococcus furiosus also found that ribosomal proteins, such as the LSU ribosomal proteins L10E, L12A, and L7AE, had obviously higher abundances at 90°C than at 70°C ( 78 ). It has been reported in E. coli that the deletion of rbfA triggers cold shock response and lower protein synthesis ( 40 ). A logical deduction regarding these analyses thus is that the upregulated ribosomal proteins are required for efficient protein synthesis against heat stress in thermophiles. In addition, both archaeal and bacterial ribosomal protein complexes in thermophiles have a higher affinity to 23S rRNA than do their mesophilic counterparts, whereas their structures are more compact ( 68, 71, 87 ). These findings strongly indicate that the translational machinery of thermophiles is so stable and efficient that functional proteins can be synthesized at sufficient amounts.

Why should DNA repair be more stringent in thermophiles?

Since DNA is more unstable at higher temperatures, the DNA repair system should be more stringent in thermophiles to maintain genomic stability. A genomic analysis of mutations in thermophiles, such as Thermus thermophilus and Sulfolobus acidocaldarius, revealed that base substitutions occur at a lower frequency in thermophiles than in mesophiles ( 24 ), and a recent study confirmed these estimations ( 42 ). A hypothesis is thus prompted in which the resulted amino acid substitutions from gene mutations are more deleterious in a thermophile than in a non-thermophile. Generally, non-synonymous substitutions are more deleterious than synonymous substitutions; therefore, the frequency of non-synonymous substitutions in thermophiles should be reduced. Friedman et al. estimated the numbers of synonymous and non-synonymous nucleotide substitutions per site between 17,957 pairs of orthologous genes from 22 pairs of closely related species of archaea and bacteria ( 30) and found that the average ratio of non-synonymous to synonymous substitutions in thermophiles was significantly lower than that in non-thermophiles, indicating that the proteins of thermophilic prokaryotes were subjected to unusually stringent functional constraints. Noort et al. further confirmed this observation and found that the amino acid substitution of lysine to arginine is associated with thermophily ( 79 ).

Why is operon regulation important for thermophiles?

A large body of evidence regarding gene expression in thermophiles indicates that operon regulation is an important mode to retain thermophile survival, because the genes located within an operon could be economically co-regulated responding to a stimulus.

Which proteins are upregulated in response to temperature?

At the proteomic level, the upregulation of chaperonin proteins, such as GroEL, GroES, DnaK, and GrpE, in response to a temperature increase was observed in several thermophilic species, including Thermoanaerobacter tengcongensis and Thermotoga maritime ( 19, 84, 85 ).

What temperature do hyperthermophiles grow?

Hyperthermophiles (mostly Archaea) grow optimally at temperatures above 80 °C with some representatives thriving even at 113 °C and higher ( Stetter, 2013 ). Occurrence of sulphate reduction at high temperature (above 100 °C) was shown by means of radio tracer ( 35 S-labelled sulphate) studies in hot deep-sea sediments retrieved from a hydrothermal vent site in the Guaymas Basin, Gulf of California ( Jørgensen, Isaksen, & Jannasch, 1992). The archaeal sulphate reducer A. fulgidus VC-16 T represents the first reported hyperthermophile among the SRP. The strain was isolated from hot sediments collected from a marine hydrothermal system at the Mediterranean island Vulcano (Italy) and displayed a Topt of 83 °C and Tmax of 92 °C ( Stetter et al., 1987 ). Research with A. fulgidus has primarily been concerned with the molecular understanding of adaptation to high temperature in the areas of dissimilatory sulphate reduction ( Parey, Fritz, et al., 2013 ), substrate uptake and ion exchange systems ( Andrade, Dickmanns, Ficner, & Einsle, 2005; Nishizawa et al., 2013), thermostability of biosynthetic enzymes (Yoneda, Sakuraba, Tsuge, Katunuma, & Ohshima, 2007 ), ether lipid biochemistry ( Lai, Springstead, & Monbouquette, 2008 ), genome-derived novel properties such as noncellulosomal cohesin ( Voronov-Goldman et al., 2011) and biogeochemically relevant sulphur isotope fractionation ( Mitchell, Heyer, Canfield, Hoek, & Habicht, 2009 ). The recently reported eubacterial Thermodesulfobacterium geofontis, isolated from Obsidian Pool (Yellowstone Park, USA), also qualifies as a hyperthermophile with a Topt 83 °C and a Tmax 90 °C ( Hamilton-Brehm et al., 2013). The supposedly sulphate-reducing crenarchaeote Caldivirga maquiligensis, isolated from an acidic hot spring in the Philippines and displaying a Topt 85 °C and a Tmax 92 °C ( Itoh et al., 1999 ), possesses a tri-split tRNA gene shedding new light on the evolution of fragmented tRNAs ( Fujishima et al., 2009 ).

What is the highest temperature for a hyperthermophile?

From these studies, the highest optimal growth temperature for an organism is 105–106 °C ( Table 1).

What is the maximum temperature of pyrodictium?

Among the Crenarchaeota, Pyrodictium and Pyrolobus (order Igneococcales) are chemolithotrophic sulfur-dependent hyperthermophiles whose maximum growth temperatures of 110 and 113 °C, respectively, represent the upper temperature limits for life known so far. Pyrodictium is a strict anaerobe and grows on H 2 and S 0. Pyrolobus is unusual in that it is capable of reducing both NO 3 − and S 2 O 3 2 − to NH 4 + and H 2 S, respectively, with H 2 as the electron donor. Desulfurococcus and Staphylothermus (order Igneococcales) are phylogenetically clearly separate from the Pyrodictium group ( Figure 1 ). These coccoid or disc-shaped organisms have an optimal growth temperature higher than 85 °C and, in contrast with the Pyrodictium group, a maximum temperature not higher than 100 °C. They can grow chemolithoautotrophically by sulfur reduction to H 2 S or heterotrophically by sulfur respiration of various organic substrates. Thermoproteus and Thermofilum (order Thermoproteales) are rod-shaped hyperthermophiles that grow in mildly acidic conditions at temperatures up to 95 °C. They are both strict anaerobes that can grow chemolithotrophically on H 2 or chemoorganotrophically on complex carbon substrates with S 0 as an electron acceptor. Pyrobaculum aerophilum (order Thermoproteales) is a rod-shaped hyperthermophile capable of aerobic respiration in the presence of very low oxygen concentrations (∼0.3%) and nitrate reduction under strictly anaerobic conditions.

What are the genes of hyperthermophiles?

We analyzed two of these, Tk-subtilisin and Tk-SP. Subtilisins from mesophilic bacteria have been widely used in the detergent industry, because of broad substrate specificity and ease of large-scale preparation. Tk-subtilisin and Tk-SP are approximately 40% identical to these mesophilic bacterial subtilisins, and exhibit extraordinarily high stability compared with the mesophilic homologs. These two hyperthermophilic subtilisins are potential candidates for application in biotechnological fields, and will provide good models for the study of maturation and stabilization mechanisms in all subtilisin-like proteases.

How does phr affect transcription?

Phr inhibits specifically cell-free transcription of its own gene and from promoters of genes of a small HSP, HSP20, and of an AAA + ATPase. The aaa+atpase and phr mRNA levels are induced after HS and during stationary growth phase in P. furiosus, indicating that the transcription of these genes is also affected by general stress and starvation. By contrast, the levels of the protein Phr are only slightly elevated during heat stress. In vitro experiments have shown that at high temperature (103 °C) Phr loses its functional conformation. The dissociation of the protein from its operator sequence may account for the high increase of phr mRNA levels detected after temperature upshift. Then, in Pyrococcus, there is a simple model for HS regulation: Phr binds promoter regions of HS genes at normothermic temperature inhibiting transcription by blocking RNAP recruitment. Subsequent release of Phr along with elevating temperature leads to activation of HS genes.

What temperature does Pyrodictium abyssi grow?

The heterotrophic archaea Hyperthermus butylicus and Pyrodictium abyssi have maximum growth temperatures of 108 and 110 °C, respectively. They grow on peptides and their growth is stimulated by the addition of H 2, CO 2, and S°.

Why are methanogens more abundant in the colonic flora of mice?

Methanogens are more abundant in the colonic flora of mice with a genetic disposition for obesity.

How do hyperthermophiles maintain their proteins?

Another way that hyperthermophiles ensure their proteins' proper function is by using heat shock proteins ( HSPs). While these HSPs are not unique to extremophiles, they are extremely important to study because HSPs found in hyperthermophiles are the most stable of their kind. HSPs are also able to prolong the life of a hyperthermophile even beyond its optimal growing temperature. By studying these proteins it may be possible to learn the mechanisms proteins use to stabilize other proteins, which may help in biosynthesis of new molecules. HSPs act as chaperone proteins that help enzymatic proteins maintain their proper conformation for longer than they would by themselves at such high temperatures. This is part of what allows P. fumarii to exist at temperatures that were long believed much too hot for life to exist.

What are the properties of hyperthermophilic archaea?

Hyperthermophiles are organisms that can live at temperatures ranging between 70 and 125 °C. They have been the subject of intense study since their discovery in 1977 in the Galapagos Rift. It was thought impossible for life to exist at temperatures as great as 100 °C until Pyrolobus fumarii was discovered in 1997. P. fumarii is a unicellular organism from the domain Archaea living in the hydrothermal vents in black smokers along the Mid-Atlantic Ridge. These organisms can live at 106 °C at a pH of 5.5. To get energy from their environment these organisms are facultatively aerobic obligate chemolithoautotrophs, meaning these organisms build biomolecules by harvesting carbon dioxide (CO 2) from their environment by using hydrogen (H 2) as the primary electron donor and nitrate (NO 3−) as the primary electron acceptor. These organisms can even survive the autoclave, which is a machine designed to kill organisms through high temperature and pressure. Because hyperthermophiles live in such hot environments, they must have DNA, membrane, and enzyme modifications that help them withstand intense thermal energy. Such modifications are currently being studied to better understand what allows an organism or protein to survive such harsh conditions. By learning what lets these organisms survive such harsh conditions, researchers can better synthesize molecules for industry that are harder to denature.

What is the best temperature for a fumarii?

Extremophiles are organisms that grow best in extremely cold, acidic, basic or hot environments. P. fumarii is a hyperthermophile, indicating that this organism grows best at extremely high temperatures (70–125 °C). P. fumarii grows best at 106 °C. Due to the extremely high temperatures this archaea is subjected to, ...

How do P. fumarii get energy?

Because organisms like P. fumarii live in such harsh environments, these archaea have needed to devise unusual ways to gather energy from the environment and protect themselves against heat stress. P. fumarii, like plants, are able to harvest CO 2 from the environment to build their biomolecules, but unlike plants, they take electrons from H 2 instead of H 2 O and transfer those electrons to NO 3−, SO 42− or O 2. This type of metabolic process is classified as chemolithoautrophism, meaning their carbon comes from an inorganic source, their final electron acceptor is not O 2 and they produce and consume their own food.

How do archaea control the flow of solutes?

Another extremely important membrane regulation modification that archaea use to control influx and efflux of solutes is the addition of cyclopentane rings within the hydrocarbon tails of the ester-linked phospholipids. The addition of these rings into the membrane allows for even tighter packing of the membrane molecules. These cyclopentane rings can exist in tetraether lipids or diether lipids. By increasing the number of atoms in the middle of the membrane, there is less space for solutes to move in or out of the cell. This helps again to control the amount of solutes moving in and out of the cell. Cyclopentane rings help to crowd the membrane's inner structure making it more difficult for the solutes to get through the membrane to the other side of cell. This is so important for the cell because at hyperthermophilic conditions, the solutes travel very fast, carrying a lot of thermal energy from the environment. If the cell did not have these rings, too many unwanted molecules would likely pass through the membrane either into or out of the cell. This would result in the slowing or complete stop of metabolic processes resulting in cell death.

What temperature can a pyrolobus fumarii live at?

It was thought impossible for life to exist at temperatures as great as 100 °C until Pyrolobus fumarii was discovered in 1997. P. fumarii is a unicellular organism from the domain Archaea living in the hydrothermal vents in black smokers along the Mid-Atlantic Ridge. These organisms can live at 106 °C at a pH of 5.5.

What are the alternate pathways used by extremophiles?

The alternate pathways used by these extremophiles are either the rTCA cycle, 3-HP cycle, 3-HP/4-HP cycle, or DC/4-HP cycle. These are likely some of the first pathways to evolve because the bacteria and archaea who use them live in environments that mirror the early Earth environments.

Overview

Research

Early research into hyperthermophiles speculated that their genome could be characterized by high guanine-cytosine content; however, recent studies show that "there is no obvious correlation between the GC content of the genome and the optimal environmental growth temperature of the organism."
The protein molecules in the hyperthermophiles exhibit hyperthermostability—that is, they can ma…

History

Specific hyperthermophiles

See also

Further reading