What are halophiles?
Nov 15, 2021 · Halophiles play an important part in ecosystems. For example, halophiles often support entire populations of wild birds. Halophiles are useful for cleaning up polluted environments. Waste water with salt concentrations more than 2% is ideal for halophiles to remove organic pollutants from.
What are the applications of halophilic microorganisms?
What are Halophiles used for? Halophiles play an important part in ecosystems. For example, halophiles often support entire populations of wild birds. Halophiles are useful for cleaning up polluted environments. Waste water with salt concentrations more than 2% is ideal for halophiles to remove organic pollutants from. Click to see full answer.
How do halophiles protect themselves from desiccation?
Jan 11, 2022 · In order to maintain osmotic pressure in their cytoplasm, halophiles accumulate molar concentrations of intracellular potassium and …
How do halophiles adapt to hypersaline environments?
The unique cellular enzymatic machinery of halophilic microbes allows them to thrive in extreme saline environments. That these microorganisms can prosper in hypersaline environments has been correlated with the elevated acidic amino acid content in their proteins, which increase the negative protein surface potential.
How are halophiles used in biotechnology?
Halophiles allow fermentation processes to run contamination free under unsterile conditions and continuous way. Halophiles have been used to produce bioplastics polyhydroxyalkanoates (PHA), ectoines, enzymes, and bio-surfactants. Genetic manipulation methods have been developed for halophiles.Nov 15, 2015
What are the industrial and environmental applications of Halophilic microorganisms?
In comparison with the thermophilic and the alkaliphilic extremophiles, halophilic microorganisms have as yet found relatively few biotechnological applications. Halophiles are involved in centuries-old processes such as the manufacturing of solar salt from seawater and the production of traditional fermented foods.
Are halophiles harmful?
Halophilic prokaryotes are rarely pathogenic: of these 52 halophilic prokaryotes only two (3.92%) species were classified in Risk Group 2 (Vibrio cholerae, Vibrio parahaemolyticus) and one (1.96%), species in Risk Group 3 (Bacillus anthracis).May 4, 2018
Why are halophiles worth investigating?
Halophilic archaea are unique microorganisms adapted to survive under high salt conditions and biomolecules produced by them may possess unusual properties. Haloarchaeal metabolites are stable at high salt and temperature conditions that are useful for industrial applications.Sep 12, 2017
How do halophiles benefit society?
Halophiles play an important part in ecosystems. For example, halophiles often support entire populations of wild birds. Halophiles are useful for cleaning up polluted environments. Waste water with salt concentrations more than 2% is ideal for halophiles to remove organic pollutants from.
What are known as halophiles?
The halophiles, named after the Greek word for "salt-loving", are extremophiles that thrive in high salt concentrations. While most halophiles are classified into the domain Archaea, there are also bacterial halophiles and some eukaryotic species, such as the alga Dunaliella salina and fungus Wallemia ichthyophaga.
Can halophiles survive without oxygen?
These results show that, rather than being toxic, presence of perchlorate can be favourable for the development of halophilic archaea in the absence of molecular oxygen, provided that a suitable electron donor and energy source is also available.
What conditions do halophiles live in?
Halophiles thrive in places such as the Great Salt Lake, Owens Lake in California, evaporation ponds, and the Dead Sea – places that provide an inhospitable environment to most lifeforms. Figure: Dead Sea: Salt builds up along the Dead Sea.Jan 3, 2021
What adaptations do halophilic bacteria have?
Halophile organisms have strategies allowing them not only to withstand osmotic stress, but also to function better in the presence of salt, in spite of maintaining high intracellular concentrations of salt, partly due to the synthesis of compatible solutes that allow them to balance their osmotic pressure.
What kingdom does halophiles belong to?
EuryarchaeotaHaloarchaea (halophilic archaea, halophilic archaebacteria, halobacteria) are a class of the Euryarchaeota, found in water saturated or nearly saturated with salt....HaloarchaeaDomain:ArchaeaKingdom:EuryarchaeotaPhylum:EuryarchaeotaClass:Halobacteria Grant et al. 20027 more rows
What chemical compound is selective for halophiles?
For example, mannitol salt agar is used to select for halophiles (e.g., Staphylococcus), while also visually differentiating species of staph based on mannitol fermentation (S. aureus) or the inability to ferment mannitol (S. epidermidis).Sep 25, 2020
Are halophiles unicellular or multicellular?
So what are they? Halobacterium are in the domain of Archea, a group of single-celled micro-organisms, and are therefore not bacteria. They can live in extreme environments. They have an aerobic metabolism and can be red or purple.
What organisms are halophiles?
The organisms that grow in saline environments are called halophiles. Halophiles belong to all three domains of life. They can be archaea, bacteria...
What conditions do halophiles live in?
Halophiles live in conditions with extreme, moderate, or slight salt concentrations. Some halophiles prefer extreme salt concentrations (15 -30 %),...
Why are they called halophiles?
The word halophiles is formed by combining two Greek words "Halo" which means salt and "philos" which means loving. The organisms grow in extreme s...
How are flagella different from bacteria?
They have smaller dimensions than their bacterial equivalents and their axial filaments contain different proteins. The diameter of archaeal flagella is about 10 nm, whereas this is 24 nm for the bacterial organelles ( Figure 8 ). Another difference is that their proteins are often glycosylated. Presumably, this is related to the requirement to sustain extreme growth conditions, be it high salinity or high temperature. Note that probably for the same reason S-layer s proteins of archaea are also glycosylated. Likewise, the N-termini of archaeal flagellin and bacterial pilin show significant homology. Moreover, the architecture of archaeal flagella bears resemblance to that of bacterial type IV pili ( Figure 9 ). This has led to the insight that the term flagellum in the archael context represents a misnomer. A recent proposal has been to coin the term archaellum.
Where is Vibrio Parahaemolyticus found?
Vibrio parahaemolyticus is a common inhabitant of marine and estuarine environments, and it commonly is found in and on the macroflora and fauna that inhabit those environments. Vibrio parahaemolyticus generally is found in temperate and tropical regions, where water temperatures are above 15 °C. Vibrio parahaemolyticus is an obligate halophile, but it can be found in salinities ranging from 5 to >30 ppt (full oceanic strength). Due to its proclivity for warmer temperatures, the prevalence of V. parahaemolyticus in the environment and seafood demonstrates a seasonality, with higher levels in the warmer months. Levels of V. parahaemolyticus in the environment, and consequently, seafood, are correlated strongly with temperature. Within the optimal temperature range, other environmental predictors for V. parahaemolyticus levels include salinity, suspended particulates, and chlorophyll a.
Do halophiles transfer DNA?
One of the bacteria-like capabilities of the Archaea, cell-to-cell conjugative transfer of DNA, appears to be quite widespread in halophiles and in Sulfolobus spp. It therefore seems to occur in both Crenarcheota and Euryarcheota. Transfer of chromosomal genes by cell fusion or cytoplasmic bridges has been observed in several halophile species, notably Haloferax mediterranei and H. volcanii, which also exhibit interspecific conjugation. Plasmid pNOB8, a 45 kb conjugatable plasmid of a Sulfolobus species isolated from a Japanese hot spring, is transferred unidirectionally and propagated at high frequency throughout a mixed culture of the Japanese isolate with either Sulfolobus solfataricus or S. islandicum, an Icelandic strain. Because of the high copy number of the plasmid in recipient cells during epidemic spread, the colonies of recipients can be distinguished visually without a selectable marker because of their small colony size, compared with the colonies of plasmid-free cells. To date, however, the conjugation phenomenon has not been exploited to any extent for genetic mapping or for strain construction.
What are the two types of hypersaline habitats?
Hypersaline habitats can be grouped into two categories: thalassohaline and athalassohaline. Thalassoha line habitats are created by evaporation of seawater, have Na + and Cl − as dominant anions and pH values close to neutrality. When evaporation proceeds, the ionic composition may change due to the precipitation of gypsum (CaSO 4 · 2 H 2 O) and other minerals beyond their solubility threshold. NaCl-saturated thalassohaline brines, such as found in saltern crystalliser ponds, often display a bright red colouration due to the large number of pigmented microorganisms ( Halorubrum and others). The ionic compositions of athalassohaline environments differ from that of seawater, often contain high concentrations of CO 32– and HCO 3− and their pH can exceed a value of 10 [ 24 ]. The term sodic soil is often used for such inland salt habitats dominated by Na 2 CO 3 or Na 2 SO 4 [ 25 ]. The vegetation around such habitats comprises typical plants, “the halophytes”. Their composition is remarkably rather similar worldwide, as distinct belt formation can be observed as a function of the salt load [ 25 ].
What is a halophile?
The halophiles, named after the Greek word for "salt-loving", are extremophiles that thrive in high salt concentrations. While most halophiles are classified into the domain Archaea, there are also bacterial halophiles and some eukaryotic species, such as the alga Dunaliella salina and fungus Wallemia ichthyophaga.
What is the color of halophiles?
Some well-known species give off a red color from carotenoid compounds, notably bacteriorhodopsin. Halophiles can be found in water bodies with salt concentration more than five times greater than that of the ocean, such as the Great Salt Lake in Utah, Owens Lake in California, the Dead Sea, and in evaporation ponds.
How do halophiles survive in high salinity?
To survive the high salinities, halophiles employ two differing strategies to prevent desiccation through osmotic movement of water out of their cytoplasm. Both strategies work by increasing the internal osmolarity of the cell. The first strategy is employed by the majority of halophilic bacteria, some archaea, yeasts, algae, and fungi; the organism accumulates organic compounds in the cytoplasm— osmoprotectants which are known as compatible solutes. These can be either synthesised or accumulated from the environment. The most common compatible solutes are neutral or zwitterionic, and include amino acids, sugars, polyols, betaines, and ectoines, as well as derivatives of some of these compounds.
Where do North Ronaldsay sheep come from?
North Ronaldsay sheep are a breed of sheep originating from Orkney, Scotland. They have limited access to freshwater sources on the island and their only food source is seaweed. They have adapted to handle salt concentrations that would kill other breeds of sheep.
Is halobacteria a family?
Halobacteriaceae is a family that includes a large part of halophilic archaea. The genus Halobacterium under it has a high tolerance for elevated levels of salinity. Some species of halobacteria have acidic proteins that resist the denaturing effects of salts. Halococcus is another genus of the family Halobacteriaceae.
What is the salt content of halophiles?
Slight halophiles prefer 0.3 to 0.8 M (1.7 to 4.8%—seawater is 0.6 M or 3.5%), moderate halophiles 0.8 to 3.4 M (4.7 to 20%), and extreme halophiles 3.4 to 5.1 M (20 to 30%) salt content. Halophiles require sodium chloride (salt) for growth, in contrast to halotolerant organisms, which do not require salt but can grow under saline conditions.
How does sodium chloride affect respiration?
The high concentration of sodium chloride in their environment limits the availability of oxygen for respiration . Their cellular machinery is adapted to high salt concentrations by having charged amino acids on their surfaces, allowing the retention of water molecules around these components.
What are halophiles used for?
Halophiles are microorganisms that can adapt to growth in moderate and high salt concentrations and in biotechnology are extensively used for a number of applications, including the production of valuable enzymes. Despite this, halophiles have remained a somewhat neglected group of bacteria. Halophiles cover all there domains, namely Archaea, Bacteria and Eucarya, and contain representatives of many different physiological types, adapted to a wide range of salt concentrations as high as salt saturation. Earlier reviews have discussed the possible applications of halophiles in biotechnological and environmental processes; DasSarma and Arora, 1997, 1 for example have provided information on the limited current and potential practical uses of these organisms.
What are halophilic microorganisms used for?
This review has highlighted other uses of halophilic microorganisms, including their use in the treatment of saline and hypersaline wastewaters, and in the production of exopolysaccharides, poly β- Halobacterium hydroxyalkanoate bioplastics and biofuels. Many of these processes have yet to be fully exploited, but the future use of halophiles in biotechnology looks very positive.
How do halophiles survive in salty environments?
Normally, organisms living in salt-rich environments lose water and die as the result of osmosis. In order to survive in salt-rich environments, the cytoplasm of halophiles must be isotonic with the environment 2. In order to reach this state, they use two different methods. In the first (mainly used by bacteria, some archaea, yeasts, algae and fungi), organic compounds are stored in the cytoplasm; such compounds help the organism survive osmotic stress 3. The most commonly used solutes used in this process are neutral amino acids and sugars 4. An important disadvantage of this method is that it requires the organism to use considerable amounts of energy. The second, and less common adaptation to salt, involves the selective intake of potassium (K +) ions into the cytoplasm. In exchange, the organism pumps sodium (Na +) ions out with the help of the sodium-potassium pump 5. Ions of sodium may also be used but less frequently so than potassium 6. This adaptation is only used by one order of bacteria and a single family of Archaea 7. An advantage of this approach is that it uses much less energy than the previously mentioned adaption. The main disadvantage with this approach is that all of the machinery within the cell (enzymes, structural proteins, etc.) must be adapted to high levels of non-organic ions and high salt levels; such an approach turns out to be much more demanding than the use of compatible solutes. Most halophiles use only use one of these two approaches, although a few halophiles can use both.
What is the first halophilic fermentative bacterial species?
The first halophilic fermentative bacterial species, Halanaerobium praevalens was isolated from the sediments of the Great Salt Lake (Utah) and characterized in 1983 8 and placed firmly in the family Bacteroidaceae as a genus with uncertain affiliation 8. The characterization of H. praevalens was followed by the isolation and characterization of Halobacteroides halobius in 1984 from the sediments of Dead Sea and similarities in 16S rRNA sequences between the two halophilic fermentative bacteria were observed leading to placement of the species in a new family, namely the Haloanaerobiaceae 9,10. A third genus was added to the family Haloanaerobiaceae in 1987, when Clostridium lortetii, was isolated from the sediments of Dead Sea and originally characterized in 1983, was transferred to a new genus of the family and renamed as Sporohalobacter lortetii. 11,12.
What is salt used for in fermenting food?
Large amounts of salt are used in the preparation of certain types of traditionally fermented foods. Such salt-rich food products are especially popular in the Far-East. Examples include ‘jeotgal’, traditional Korean fermented seafood, the Japanese ‘fugunoko nukazuke’ prepared by fermentation of salted puffer fish ovaries in rice bran, and ‘nam-pla’, a Thai fish sauce. The latter product is made by adding two parts of fish and one part of marine salts. The mixture is covered with concentrated brine (25–30% NaCl) and allowed to ferment for around a year. Surprisingly relatively little is known about the microorganisms involved in the preparation of these foods and about the roles they play in the production process. In some cases, the salt concentration during the fermentation process is sufficiently high for the development of Archaea of the family Halobacteriaceae. The first halophilic archaeon obtained from Thai fish sauce (nam pla) was an isolate resembling Halobacterium salinarum 29, and two new species, Halococcus thailandensis and Natrinema gari, were recently isolated 30,31. Halalkalicoccus jeotgali is a novel isolate obtained from shrimp jeotgal 32.
What are biosurfactants made of?
Biosurfactants and other biopolymers have been produced using non-fermentative halophilic bacteria, but not fermentative halophiles a result which may reflect the fact that fermentative halophilic strains have been relatively little studied. Biosurfactants are biopolymers which are able to decrease surface tension in liquids thereby increasing the motility of hydrophobic hydrocarbons. They have been used in the bioremediation of oil-contaminated hypersaline soil or water, and may also be useful for use in in situ microbialy-enhanced oil recovery. The is based on the fact that many petroleum reservoirs are hypersaline and exist at high temperature, making it likely that halothermophilic bacteria could find a practical us in this technology 33.
What are halophilic enzymes?
Halophilic microorganisms produce stable enzymes, including many hydrolytic enzymes such as DNAses, lipases, amylases, gelatinises, and proteases. Such enzymes are able to function under high concentrations of salt which would normally lead to the precipitation or denaturation of most proteins, including enzymes. Most halophilic enzymes are inactivated and denatured at concentrations of NaCl below 1M. E nzymes produced by halophilic fermentative bacteria in contrast are salt tolerant and, actually, salt-requiring due to their need to maintain high intracellular ion concentrations maintained for balancing the osmotic pressure in hypersaline environments. Most interest in relation to halophilic enzymes has been devoted to isomerases and hydrolases, including amylases that catalyze the bioprocessing of starch and galactosidases which catalyze the bioprocessing of lactose. Salt-require ring enzymes have been cloned and produced as inactive forms in Escherichia coli and subsequently successfully activated with increase of salt concentration 34.
