What is another word for psychrophile?
Freebase(0.00 / 0 votes)Rate this definition: Psychrophile. Psychrophiles or cryophiles are extremophilic organisms that are capable of growth and reproduction in cold temperatures, ranging from −15°C to +10°C. Temperatures as low as −15°C are found in pockets of very salty water surrounded by sea ice.
What is a psychrophilic organism?
Morita (1975) defined psychrophiles as organisms having an optimal temperature for growth at about 15°C or lower, a maximal temperature for growth at about 20°C, and a minimal temperature for growth at 0°C or lower.
What are psychrophiles and thermophiles?
They can be contrasted with thermophiles, which are organisms that thrive at unusually high temperatures. Psychrophile is Greek for 'cold-loving'. Many such organisms are bacteria or archaea, but some eukaryotes such as lichens, snow algae, fungi, and wingless midges, are also classified as psychrophiles.
What is a cryophilic organism?
Psychrophiles or cryophiles are extremophilic organisms that are capable of growth and reproduction in cold temperatures, ranging from −15°C to +10°C. Temperatures as low as −15°C are found in pockets of very salty water surrounded by sea ice.
What do you mean by psychrophile?
Psychrophiles are extremophilic bacteria or archaea which are cold-loving having an optimal temperature for growth at about 15°C or lower, a maximal temperature for growth at about 20°C and a minimal temperature for growth at 0°C or lower.
What is the Greek word of psychrophile?
The term 'psychrophile' reflects this—from Greek, psukhros meaning 'cold' and philein, 'to love'.
Where do you find psychrophile?
Psychrophiles are considered as a type of extremophiles. They are found inhabiting the alpine and arctic soils, deep ocean waters, glaciers, snowfields, etc. Synonym(s): cryophiles.
What is psychrophiles and Psychrotrophs?
Psychrotrophic microorganisms have a maximum temperature for growth above 20 degrees C and are widespread in natural environments and in foods. Psychrophilic microorganisms have a maximum temperature for growth at 20 degrees C or below and are restricted to permanently cold habitats.
What is an example of psychrophile?
Psychroba... cryohalole...Psychroba... arcticusPsychroba... immobilisPseudoglu... cumminsiiPsychroba... phenylpyr...Psychroba... sanguinisPsychrophile/Representative species
What is the scientific name for psychrophile?
Psychrophiles or cryophiles (adj. psychrophilic or cryophilic) are extremophilic organisms that are capable of growth and reproduction in low temperatures, ranging from −20 °C (−4 °F) to 20 °C (68 °F).
Why are psychrophiles important to humans?
Psychrophiles and psychrotrophs are important decomposers in cold climates and their enzymes are of interest to biotechnology. Psychrophiles contain specific proteins, particularly enzymes that can still function (albeit at a reduced rate) in low temperatures (at temperatures at or near 0 °C ).
Which bacteria is psychrophilic?
Psychrophilic bacteria include Gram-negative genera such as Pseudoalteromonas, Moraxella, Psychrobacter, Flavobacterium, Polaromonas, Psychroflexus, Polaribacter, Moritella, Vibrio, and Pseudomonas; Gram-positive genera such as Arthrobacter, Bacillus, Micrococcus species; microalgae such as Chlamydomonadales and ...
Are psychrophiles pathogenic?
Psychrophilic pathogens can be potential hazard for public health. One of the most neglected areas has been the issue of psychrophilic pathogens which are related with refrigerated items in our households.
Are Psychrotrophs the same as psychrophiles?
Summary – Psychrophiles vs Psychrotrophs Psychrophiles and psychrotrophs are two types of microorganism groups that grow at cold temperatures. They are cold-loving extremophiles. Psychrophiles have the optimum temperature of 15 0C or lower while psychrotrophs have an optimal temperature of 20-40 0C.
How do psychrophiles survive in the cold?
Some psychrophiles produce antifreeze or ice-binding (AFP) proteins (Fig 3), which bind to and control ice crystal growth and recrystallization by lowering the freezing point (thermal hysteresis) 79.
What is a psychrophile?
Psychrophile is Greek for 'cold-loving', from ψυχρός ( psukhrós: cold, frozen). Many such organisms are bacteria or archaea, but some eukaryotes such as lichens, snow algae, fungi, and wingless midges, are also classified as psychrophiles.
Why is it confusing to call a psychrophile a psychrophile?
The confusion between the terms psychrotrophs and psychrophiles was started because investigators were unaware of the thermolability of psychrophilic organisms at the laboratory temperatures. Due to this, early investigators did not determine the cardinal temperatures for their isolates.
What are the environmental constraints that psychrophiles face?
These constraints include high pressure in the deep sea, and high salt concentration on some sea ice.
How are psychrophiles protected from freezing?
Psychrophiles are protected from freezing and the expansion of ice by ice-induced desiccation and vitrification (glass transition), as long as they cool slowly. Free living cells desiccate and vitrify between −10 °C and −26 °C. Cells of multicellular organisms may vitrify at temperatures below −50 °C.
Why are psychrophiles important?
They must also overcome the stiffening of their lipid cell membrane, as this is important for the survival and functionality of these organisms. To accomplish this, psychrophiles adapt lipid membrane structures that have a high content of short, unsaturated fatty acids. Compared to longer saturated fatty acids, incorporating this type of fatty acid allows for the lipid cell membrane to have a lower melting point, which increases the fluidity of the membranes. In addition, carotenoids are present in the membrane, which help modulate the fluidity of it.
Where are cryophiles found?
psychrophilic or cryophilic) are extremophilic organisms that are capable of growth and reproduction in low temperatures, ranging from −20 °C to +10 °C. They are found in places that are permanently cold, such as the polar regions and the deep sea.
Where can psychrotrophic bacteria be found?
They provide an estimation of the product's shelf life, but also they can be found in soils, in surface and deep sea waters, in Antarctic ecosystems, and in foods. Psychrotrophic bacteria are of particular concern to the dairy industry.
What is a psychrophile?
Over the next 60 years, the term psychrophile continued to be in use to describe cold-adapted microbes according to the ability to reproduce in the cold, regardless of the upper temperature limit for growth. That limit, with few exceptions, fell above room temperature, thus overlapping with the thermal category of mesophiles. These microbes today are called psychrotolerant (or psychrotrophic), with the descriptor psychrophilic reserved for organisms that fit the more precise definition provided by the American marine microbiologist Morita (in 1975), based on cardinal growth temperatures: minimal temperature ( Tmin) of 0°C or lower, optimal temperature ( Topt) of 15°C or lower, and maximal temperature ( Tmax) of about 20°C ( Fig. 1 ). By this definition, which provided much needed clarity at the time and remains in wide use today, the first true psychrophile was discovered by Tsiklinsky as part of a French expedition to Antarctica (1903–05). Another half-century would pass before the abundance and functional roles of true psychrophiles in cold environments would be appreciated. First, microbiologists had to learn about the sensitivity of cold-adapted microbes to room temperature (even to unchilled pipets) during isolation procedures. Eventually, after many enrichment studies using 4–6°C (convenient refrigerator temperature) and reports of predominantly psychrotolerant isolates, came the understanding that the temperature of initial enrichment influences the thermal nature of the resulting isolates: enrichments near the freezing point (e.g., at −1°C for marine samples) are more likely to yield psychrophilic than psychrotolerant bacteria.
What is the difference between cryophiles and psychrophiles?
Psychrophiles are cold-loving bacteria or archaea, whereas cryophiles are cold-loving higher biological forms (e.g., polar fish). Owing to precedence, the term psychrophile has been retained. Morita (1975) defined psychrophiles as organisms having an optimal temperature for growth at about 15°C or lower, a maximal temperature for growth at about 20°C, and a minimal temperature for growth at 0°C or lower. The term, psychrotroph (also termed psychrotolerant), was retained to denote organisms that have the ability to grow at low temperatures, but have their optimal and maximal growth temperatures above 15 and 20°C, respectively. The reason why the maximal growth temperature was set at 20°C was simply because laboratory temperature in the United States is around 21–22°C, which is not considered cold. Although it is recognized that there is a continuum of cardinal temperatures among the various thermal groups, the above definition is a useful one because it has relevance in terms of their respective ecological distributions, as psychrophiles are limited to permanently cold environments ( Baross and Morita, 1978 ). Most microbiologists have accepted the foregoing definitions, though there are differences in usage: food and dairy microbiologists prefer the adjective “psychrotrophic,” whereas environmental microbiologists more commonly use “psychrotolerant.”
When were psychrophiles first discovered?
Psychrophiles were first reported in 1884, but most of the early literature actually dealt with psychrotrophic bacteria and not with true psychrophiles. Since investigators were not working with extreme cold-loving bacteria, there was much debate and, as a result, many terms were coined to designate psychrophiles. These terms were cryophile, rhigophile, psychrorobe, thermophobic bacteria, Glaciale Bakterien, facultative psychrophile, psychrocartericus, psychrotrophic and psychrotolerant ( Morita, 1975 ). This proliferation of terms also resulted from the fact that no true cold-loving bacteria existed in the various culture collections. Ingraham (1962) wrote, “Other authors have felt that the term psychrophile should be reserved for bacteria whose growth temperature optima are below 20°C if and when such organisms are found.” Because of this situation the research on true psychrophiles was neglected, especially when compared to the research on thermophiles. The first true psychrophiles, employing the foregoing definition, to be described taxonomically in the literature were Vibrio ( Moritella gen. nov.) marinus ( marina comb. nov.) MP-1 and Vibrio ( Colwellia gen. nov.) psychroerythrus ( psychrerythraea comb. nov.) in 1964 and 1972, respectively. The first genome of a psychrophile was obtained for Colwellia psychrerythraea 34H, isolated from Arctic marine sediments ( Methé et al., 2005 ). Since then, many more have been sequenced and through both proteomic and genomic analyses have been shown to exhibit cold-specific adaptations ( Lauro et al., 2011; Collins, 2015 ).
Is Listeria monocytogenes a saprophyte?
The organism is often found in fermented feedstuffs such as spoiled silage. Listeria is a saprophyte and a psychrophile that prefers microaerophilic conditions. See Liu (2009) for information on Listeria.
Why are psychrophiles important?
Psychrophiles and psychrotrophs are important decomposers in cold climates and their enzymes are of interest to biotechnology.
What temperature do psychrotrophs grow?
Psychrotrophs (also known as psychrotolerant): Psychrotroph is a variant of psychrophile, which grows at 0°C but displays an optimum temperature in the mesophile range, nearer room temperature (15-25°C). They are found in many natural environments in temperate climates and are responsible for the spoilage of refrigerated food.
Why do thermophiles have chaperone proteins?
Thermophiles express protective chaperone proteins to help with protein folding and to help maintain their native structure. In addition, the ether linkage of the thermophilic and hyperthermophilic archaea is more thermostable than the ester linkage of phospholipids.
Can psychrophiles grow at temperature?
Psychrophilic proteins rapidly denature above their temperature optima and cannot function at body temperatures of warm-blooded animals (37°C) so psychrophiles are unable to grow at even moderate temperatures.
Do psychrophiles have fatty acids?
To maintain the semifluid consistency of the plasma membrane at low temperature, psychrophiles have an increased amount of unsaturated and shorter-chain fatty acids in their plasma membranes . Some psychrophiles, particularly those from the Antarctic have been found to contain polyunsaturated fatty acids.
Overview
Psychrophiles or cryophiles (adj. psychrophilic or cryophilic) are extremophilic organisms that are capable of growth and reproduction in low temperatures, ranging from −20 °C (−4 °F) to 20 °C (68 °F) . They have an optimal growth temperature at 15 °C (59 °F). They are found in places that are permanently cold, such as the polar regions and the deep sea. They can be contrasted with t…
Biology
The cold environments that psychrophiles inhabit are ubiquitous on Earth, as a large fraction of our planetary surface experiences temperatures lower than 10 °C. They are present in permafrost, polar ice, glaciers, snowfields and deep ocean waters. These organisms can also be found in pockets of sea ice with high salinity content. Microbial activity has been measured in soils frozen below −3…
Psychrotrophic bacteria
Psychrotrophic microbes are able to grow at temperatures below 7 °C (44.6 °F), but have better growth rates at higher temperatures. Psychrotrophic bacteria and fungi are able to grow at refrigeration temperatures, and can be responsible for food spoilage and as foodborne pathogens such as Yersinia. They provide an estimation of the product's shelf life, but also they can be found in soils, in surface and deep sea waters, in Antarctic ecosystems, and in foods.
Psychrophilic microalgae
Microscopic algae that can tolerate extremely cold temperatures can survive in snow, ice, and very cold seawater. On snow, cold-tolerant algae can bloom on the snow surface covering land, glaciers, or sea ice when there is sufficient light. These snow algae darken the surface of the snow and can contribute to snow melt. In seawater, phytoplankton that can tolerate both very high salinities and …
Psychrotrophic insects
Insects that are psychrotrophic can survive cold temperatures through several general mechanisms (unlike opportunistic and chill susceptible insects): (1) chill tolerance, (2) freeze avoidance, and (3) freeze tolerance. Chill tolerant insects succumb to freezing temperatures after prolonged exposure to mild or moderate freezing temperatures. Freeze avoiding insects can survive extende…
Psychrophile versus psychrotroph
In 1940, ZoBell and Conn stated that they had never encountered "true psychrophiles" or organisms that grow best at relatively low temperatures. In 1958, J. L. Ingraham supported this by concluding that there are very few or possibly no bacteria that fit the textbook definitions of psychrophiles. Richard Y. Morita emphasizes this by using the term psychrotroph to describe organisms that do not meet the definition of psychrophiles. The confusion between the terms p…
See also
• Chionophile
• Halophile
• Ice algae
• Mesophile
Further reading
• Bej, Asim K.; Jackie Aislabie; Ronald M. Atlas (15 December 2009). Polar Microbiology: The Ecology, Biodiversity and Bioremediation Potential of Microorganisms in Extremely Cold Environments. Crc Pr Inc. ISBN 978-1420083842.
• Murata, Yoshinori; et al. (2006). "Genome-wide expression analysis of yeast response during exposure to 4C". Extremophiles. 10 (2): 117–128. arXiv:1109.6589. doi:10.1007/s00792-005-0480-1. PMID 16254683. S2CID
• Bej, Asim K.; Jackie Aislabie; Ronald M. Atlas (15 December 2009). Polar Microbiology: The Ecology, Biodiversity and Bioremediation Potential of Microorganisms in Extremely Cold Environments. Crc Pr Inc. ISBN 978-1420083842.
• Murata, Yoshinori; et al. (2006). "Genome-wide expression analysis of yeast response during exposure to 4C". Extremophiles. 10 (2): 117–128. arXiv:1109.6589. doi:10.1007/s00792-005-0480-1. PMID 16254683. S2CID 11658804.