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On 24 AUG 2008, Extremophile was linked from slashdot, a high-traffic website. ( Traffic) All prior and subsequent edits to the article are noted in its revision history.

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Is methanophile a term in current usage? I've more often (only?) heard methanotrope used. I'll google it sometime to check, but would welcome some other commentary.

Also, to what extent does extremophile refer to single-cell organisms? Are halophytes, (which, if I recall correctly, are plants that tolerate salty conditions) extremophiles? Is being tolerant of extreme conditions (for some definition of extreme) sufficient, or must an organism thrive or require extreme conditions?

There was a picture in this month's National Geographic (my in-laws buy it for me, because I tend to read it when I'm at my in-laws :-) of an algal mat growing in a volcanically active region of the Kamchatka Peninsula--I was wondering if the algae pictured qualified as an extremophile

-- dja

I agree with you about methanogens. Many are mesophilic. The same is true of endoliths. I'm going to remove these two.

With regards to your question about single celled organisms. The term is is not limited to unicellular life, but the vast majority of examples are single celled. Along these lines, I added a link to antarctic krill and made the existing link to some extrempophilic insects more prominent. Jmeppley 01:41, 6 Nov 2004 (UTC)

A lot of this page bears a strong resemblance to this: [ [1]] I assume the original material is public domain, or the authors are the same, or something, but I just wanted to be sure. -- User:Stuart Presnell

As far as I know methanogens are not extremophiles per se - most of them are mesophiles, they love temperatures between 20-40 degree celsius. All methanogens are archaea, indeed the term methanogen just refers to the fact that these organisms produce methane not more. -- not a wikipedia member yet

According to the article mesophiles and aerobes are on the list of extremophiles, which makes people extremophiles. Am I missing something here, or do we need to put non-extremophiles in a separate list? -- ChadThomson 10:53, 3 October 2005 (UTC) reply

(I moved this topic to the en to be in line with conventions)

Wow, how did those get in there. Mesophile is the opposite of extremophile. I'm taking that out as well as aerobe, anaerobic, ad anything else that refers to oxygen levels. Extremophilism is a qualitative concept for the most part, so these are all up for debate at some level, but virtually every body of water and mud puddle in the world supports anaerobic organisms.

What I took out

• Aerobe: requires O₂ to survive.
• Anaerobic: does not need O₂ to survive.
• Mesophile: An organism that thrives in temperatures between 15-60 °C.
• Microaerophilic: requires levels of O₂ that are lower than atmospheric levels.

OK, so I re-read the article and it has a non-human slant. The end of the first paragraph sets up the list to include everything I just took out. While I appreciate that the terme is very anthropocentric, the term is non the less defined that way and we can't redefine a word for the sake of a species-neutral POV. I'm taking out much of this language, although I'll leave in the part pointing out that it is defined from a human's point of view. Jmeppley 18:03, 3 October 2005 (UTC) reply

‘Extremophiles’ are organisms that are able to live in extreme environments; areas of extremely high/low temperatures, high salinity, pH and pressure. These organisms, able to survive in these extreme environments, have unique properties that have allowed their enzymes to be used in industry to improve ‘enzyme-driven’ transformations in chemical, food & pharmaceutical applications1. It is the use of these enzymes that allows scientists to carry out reactions in conditions under which the reaction would normally cease to occur.

Extremophiles were first discovered around 40yrs ago and since ‘more than $250 million’6 has been spent on scientists in industry to discover ways to extract and use their enzymes. The enzymes found within extremophiles, called extremozymes, are used to speed up chemical reactions in order to obtain bigger percentage yields and improve the quality of foods and drugs in wide use in our society today.

The enzymes found inside extremophiles are similar to the enzymes found inside humans and other living organisms- both prokaryotic and eukaryotic. Enzymes are proteins and are sometimes ‘biological catalysts’4 Enzymes are able to speed up reactions by lowering the activation energy (energy needed to break the bonds to begin reaction) of a certain reaction. Enzymes are often specific to a certain molecule and most are produced naturally within the organism itself. For example in extremophiles, the protein catalysts allow chemical reactions to occur that allow the extremophiles to survive within its environment. Before extremophiles were discovered, proteins used in industry had to be protected from breaking down and denaturing (becoming unable to be used). “Scientists hope that the proteins in extremophiles will not need special treatment like regular proteins”6. This will save all industries a great deal of money.

The type of enzyme extracted from extremophiles depends on the conditions and environment in which the extremophiles lives in. Several different kinds of extremophiles exist, each which unique properties: Acidophiles are microorganisms that are able to survive in highly acidic environments. Different acidophiles live in habitats of various pHs, ranging from 1-5. The enzymes extracted from acidophiles include amylases & cellulases, which can be used in industry to make detergents, food & animal feed and also starch processing.

Thermophiles are extremophiles that live in a habitat of extremely high temperature. The enzymes within them are advantageous for industry because at high temperatures most enzymes used break down, or denature and so are unable to complete the given reaction. Also, the ‘solubility of many reaction components is significantly improved’ at a higher temperature. Enzymes from thermophiles include Xylanases- used for paper bleaching, Glucosyl hydrolases- used for food processing and textiles and Chitinases- used for chitin modification in food and health products. Halophiles are extracted from hyper saline environments due to their ‘ability to obtain an osmotic balance’6, meaning able to maintain and control water gain/loss even in an extremely salty environment. Enzymes from Halophiles include Proteases and dehydrogenases- used in peptide (protein synthesis) and organic media respectively.

Extremophiles are not only extracted from environments of high/low temp and salinity but also high pressure habitats. Peizophiles are able to withstand pressured environments up to 130Mpa. Pressure-resistant enzymes, like the ones extracted from Peizophiles, are useful in industry as high pressures are used for food sterilisation and also the production of household antibiotics.. Therefore, with the use of the extremozymes from Peizophiles, food sterilisation and antibiotic production could occur at higher pressures and at a better standard and rate.

In addition, other classes of extremophiles exist, although little is still known about them. These include; Radiophiles (exist under extreme radiation), Metallophiles (high metal concentrations) and Microaerophiles (under lack of oxygen). While the number of extremozymes extracted from extremozymes continues to grow, scientists are working on sequencing their genomes- listing the genes present in organisms, in order to improve the ways in which industry and food production occur in our society today.

REFERENCES: 1. “Extremophiles as a source for novel enzymes” Bertus vanden Berg, 2003, Current opinion in Microbiology, 6; 213-218 (vbB) 2. “The hunt for living gold” Holger Breithaupt, 2001, EMBO Reports, 2; 968-971 (B) 3. “Biology”, Knox-Ladiges-Evans-Saint, 2005, McGraw-Hill, 2; 53-63 4. “Concepts in Biology 10th Edit”, Eldon.D.Enger- Frederick.C.Ross, 2003, McGraw-Hill

    Higher Education, 5; 85-93

5. www.wikipedia.org.au/extremophiles 6. http://library.thinkquest.org/CRO212089/hisextrem.htm 7. http://www.wissen.swr.de/sf/begleit/bg0057/bg0057x/bg0057xx/gj08_026.jpg

This text was written by User:Lmchalwell and moved here by User:Fram. Fram 11:15, 29 August 2006 (UTC) reply

Lithoautotrophy, chemolithoautotrophy, and oligotrophy describe how an organism obtains its carbon/energy. This is different from the other categories of extremophiles, which are based on the physical parameters of locales where extremophiles thrive. Oligotrophy in specific is a bit jarring in the list of extremophiles since many microbes can survive oligotrophic conditions. My exposure to the field as a researcher gives me the impression that the modes of carbon requisition is generally not considered as a form of extreme survival trait like the ability to withstand and thrive in waters at 100oC is.

-- Qifeng 00:55, 30 August 2006 (UTC) reply

I created a template for extremophiles. Please fee free to edit it and make it better. Remember 16:10, 14 January 2007 (UTC) reply

I removed "It is estimated that these microbes comprise anywhere from 1/3 to over 1/2 the living biomass on the planet (D’Hondt, Ridge 2000), and the populations extend more than 730 meters below the seafloor." as the cited reference was not given in the ref section and I don't find such a paper with a quick search. Vsmith ( talk) 12:21, 27 February 2008 (UTC) reply

Are endoliths extremophiles per se? -- Antorjal ( talk) 13:44, 30 June 2009 (UTC) reply

GFAJ-1 is not that special it can life in A nutritionally limited environment and is therfore a Oligotroph. I suggest to remove it from the list. -- Stone ( talk) 18:30, 4 December 2010 (UTC) reply

I agree that it should be removed, if only on the basis that it is not a "type" of extremophile, but an example of an extremophile. -- leuce ( talk) 11:52, 5 December 2010 (UTC) reply

The polyextremophile article should be merged here. After several years, there is nothing but a definition and a few examples, showing that polyextremophiles have more than a single extrmeophile charatceristic, but there is nothing beyond that. A merger would result in an extra sentence or two. -- EncycloPetey ( talk) 18:16, 26 March 2011 (UTC) reply

Agreed. Danger ( talk) 21:42, 26 March 2011 (UTC) reply

"Thermophiles, a type of extremophile, produce some of the bright colors of Grand Prismatic Spring, Yellowstone National Park"

The image is so unworldly it was unclear that it was not an image of the organism itself until I viewed the article of the Spring. Can we switch that around and mention the name of the spring first followed by "receives its color from ..." to make this more clear? Drakcap ( talk) 21:35, 13 October 2018 (UTC) reply

I agree. To editor Drakcap:. -- Sm8900 ( talk) 20:19, 11 September 2019 (UTC) reply

The example species are in the wrong rows. e.g Clostridium paradoxum being placed in the acidic row when on the page for it it says "Clostridium paradoxum is a moderately thermophilic anaerobic alkaliphile bacteria." - Li, Y.; Mandelco, L.; Wiegel, J. (1993). "Isolation and Characterization of a Moderately Thermophilic Anaerobic Alkaliphile, Clostridium paradoxum sp. nov". International Journal of Systematic Bacteriology. 43 (3): 450–460. doi:10.1099/00207713-43-3-450. ISSN 0020-7713.

It all seemed a bit jumbled, not sure which others are wrong — Preceding unsigned comment added by Thomas Hasson ( talk • contribs) 10:39, 4 February 2020 (UTC) reply

Synechococcus lividus is listed as a cold-loving extremophile in the table, but it is not mentioned in the reference given, and another article I found describes it at an obligate thermophile [2]. The reference includes a table where  Arthrobacter arilaitensis (-26.0±0.8°C), Corynebacterium variabile (-25.6±0.6°C) and Chlamydomonas nivalis (-24.2±0.8°C) are the most cold-tolerant entries. I propose replacing lividus with these. Any objections? Amaurea ( talk) 16:35, 8 February 2020 (UTC) reply

@ Rowan Forest:, I think you were the one who added lividus to the table. Do you think it's in the right row? Amaurea ( talk) 16:40, 8 February 2020 (UTC) reply

I suggest that we focus our efforts on the topic of extramophiles in the following direction. Let's publish locations in the world where one type of bacterium is isolated only in this particular location. Petrov Russia ( talk) 09:36, 16 January 2021 (UTC) reply

Where the hell is this coming from? Earliest forms of life is linked as a "see also". "Dating back to more than 40 million years ago" can't be right, because more than 40 million should be also more than a billion. Also in the Characteristics section the same 40 million is specified for viable spores, which goes against this. 40 million years is nothing. Archaea exist for billions of years. I guess this is better removed until something more credible can be added. — Preceding unsigned comment added by Dqeswn ( talk • contribs) 14:00, 23 April 2022 (UTC) reply

I think the article confuses (uses sources that confuse) the difference between a habitable environment and a survivable environment. Most definitions of 'life' require both the existence of metabolism and reproduction. Inhabiting an environment requires both. Surviving in that environment requires neither. If the definition is going to define an extremophile as inhabiting OR surviving in environments which are considered 'extreme', then that should be made clear. I don't think that using survival to define the term is wise or logically consistent. Any references to spores should be deleted, imho. 174.130.71.156 ( talk) 20:39, 27 January 2023 (UTC) reply

"Recent research carried out on extremophiles in Japan involved a variety of bacteria including Escherichia coli and Paracoccus denitrificans being subject to conditions of extreme gravity. The bacteria were cultivated while being rotated in an ultracentrifuge at high speeds corresponding to 403,627 g (i.e. 403,627 times the gravity experienced on Earth). P. denitrificans was one of the bacteria which displayed not only survival but also robust cellular growth under these conditions of hyperacceleration"

A lot of bacterium (single cell, filled with fluid) in hyperacceleration, can survive this, but not by directly enduring the spin gravity in the case of the experiment, but the fact that it results in high pressure rather than being squeezed sideways out of shape as with non-fluid surrounded life forms. The pressure in the fluid increases due to the spin gravity, but otherwise the effects of the extreme gravity are not translated onto the lifeform. For a lot of bacterium high pressure doesn't change much if anything at all.

Also, experimentation with people undergoing high-g's in a fluid bubble have yielded that even human bodies can experience high-g's well beyond 30 G, if and when the pressure is well maintained before the acceleration, during the acceleration and after. If the pressure management fails it can cause acute decompression syndrome. Minimization of pressure differences through artificial re-pressurization with fast response control is neccesary.