Endolith lifeform found inside an Antarctic rock

An endolith or cryptoendolith is an organism (archaea, bacterium, or fungus) that lives inside rock, coral, animal shells, or in the pores between mineral grains. Many are extremophiles; living in places previously thought inhospitable to life. They are of particular interest to astrobiologists, who theorize that endolithic environments on Mars and other planets constitute potential refugia for extraterrestrial microbial communities. Image File history File links Cryptoendolith. ... A crab is an example of an organism. ... Phyla / Classes Phylum Crenarchaeota Phylum Euryarchaeota     Halobacteria     Methanobacteria     Methanococci     Methanopyri     Archaeoglobi     Thermoplasmata     Thermococci Phylum Korarchaeota Phylum Nanoarchaeota Archaea (; from Greek αρχαία, old ones; singular Archaeum, Archaean, or Archaeon), also called Archaebacteria (), is a major division of living organisms. ... Phyla/Divisions Actinobacteria Aquificae Bacteroidetes/Chlorobi Chlamydiae/Verrucomicrobia Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Nitrospirae Omnibacteria Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Bacteria (singular, bacterium) are a major group of living organisms. ... Divisions Chytridiomycota Zygomycota Glomeromycota Ascomycota Basidiomycota Deuteromycota A fungus (plural fungi) is a eukaryotic organism that digests its food externally and absorbs the nutrient molecules into its cells. ... The rocky side of a mountain creek near Orosí, Costa Rica. ... Subclasses Alcyonaria Zoantharia See text for orders. ... Various seashells The hard, rigid outer covering of certain animals is called a shell. ... A pore, in general, is some form of opening, usually very small. ... Minerals are natural compounds formed through geological processes. ... An extremophile is an organism, usually unicellular, which thrives in or requires extreme conditions. ... Proposed Amazonian Refugia from Haffer, 1969 In the most basic biological sense refugia (singular: refugium) refer to locations of isolated or relict populations of once widespread animal or plant species. ...

Environment

Endoliths have been found in rock down to a depth of 9,600 feet (3 km), though it is unknown if that is their limit (due to the cost involved in digging so deeply).^[1][2] The main threat to their survival seems not to result from the pressure at such depth, but from the increased temperature. Judging from hyperthermophile organisms, the temperature limit is at about 110°C, which limits the possible depth to 4 km below the continental crust, and 7 km below the ocean floor. Endolithic organisms have also been found in surface rocks in regions of low humidity (hypolith) and low temperature (psychrophile), including the Dry Valleys and permafrost of Antarctica.^[3] A foot (plural: feet) is any of several old units of distance or length, measuring around a quarter to a third of a meter. ... A kilometer (Commonwealth spelling: kilometre), symbol: km is a unit of length in the metric system equal to 1,000 metres (from the Greek words χίλια (khilia) = thousand and μέτρο (metro) = count/measure). ... Hyperthermophiles produce some of the bright colors of Grand Prismatic Spring, Yellowstone National Park A hyperthermophile is an organism that thrives in extremely hot environments - that is, hotter than around 60°C. The optimal temperatures are between 80°C and 110°C; in fact, the recently-discovered Strain 121 [1... The Celsius scale is a temperature scale named after the Swedish astronomer Anders Celsius (1701 â€“ 1744), who first proposed a similar system two years before his death. ... To meet Wikipedias quality standards, this article or section may require cleanup. ... The worlds oceans as seen from the South Pacific Ocean Oceans (from Okeanos in Greek, the ancient Greeks noticing the strong current that flowed off Gibraltar and assuming it was a great river) cover almost three quarters (71%) of the surface of the Earth, and nearly half of the... In Arctic and Antarctic ecology, a hypolith is a photosynthetic organism that lives underneath rocks in climatically extreme deserts such as Cornwallis Island and Devon Island in the Canadian high Arctic. ... Psychrophiles are extremophilic organisms that are capable of growth and reproduction in cold temperatures. ... The McMurdo Dry Valleys are a row of valleys in Antarctica located within Victoria Land west of McMurdo Sound. ... In geology, permafrost or permafrost soil is a thermal condition where ground material stays at or below 0°C for two or more years. ...

Survival

Endoliths can survive by feeding on traces of iron, potassium, or sulfur. (See lithotroph.) Whether they metabolize these directly from the surrounding rock, or rather excrete an acid to dissolve them first, remains to be seen. The Ocean Drilling Program found microscopic trails in basalt from the Atlantic, Indian, and Pacific oceans that contain DNA.^[4][5] Photosynthetic endoliths have also been discovered. General Name, Symbol, Number iron, Fe, 26 Chemical series transition metals Group, Period, Block 8, 4, d Appearance lustrous metallic with a grayish tinge Atomic mass 55. ... General Name, Symbol, Number potassium, K, 19 Chemical series alkali metals Group, Period, Block 1, 4, s Appearance brownish white Atomic mass 39. ... General Name, Symbol, Number sulfur, S, 16 Chemical series nonmetals Group, Period, Block 16, 3, p Appearance lemon yellow Atomic mass 32. ... A lithotroph is a microorganism which uses an inorganic substrate to synthesize all its organic molecules. ... Metabolism (from Greek μεταβολισμός metabolismos) is the biochemical modification of chemical compounds in living organisms and cells. ... Excretion is the biological process by which an organism chemically separates waste products from its body. ... For other uses, see Acid (disambiguation). ... The Ocean Drilling Program (ODP) was an ocean drilling effort by the National Science Foundation from 1983 to 2003. ... Basalt Basalt is a common gray to black volcanic rock. ... The Atlantic Ocean is the second-largest ocean, covering approximately one-fifth of the Earths surface. ... The general structure of a section of DNA Deoxyribonucleic acid (DNA) is a nucleic acid that contains the genetic instructions for the biological development of a cellular form of life or a virus. ...

As water and nutrients are rather sparse, endoliths have a very slow procreation cycle. Early data suggests that some only engage in cell division once every hundred years. Most of their energy is spent repairing cell damage caused by cosmic rays or racemization, and very little is available for procreation or growth. It is thought that they weather long ice ages in this fashion, emerging when the temperature in the area warms.^[2] Reproduction is the creation of one thing as a copy of, product of, or replacement for a similar thing, e. ... This article or section does not cite its references or sources. ... Cosmic rays can loosely be defined as energetic particles originating outside of the Earth. ... In chemistry racemization refers to partial conversion of one enantiomer into another. ... Variations in CO2, temperature and dust from the Vostok ice core over the last 400 000 years For the animated movie, see Ice Age (movie). ...

Slime

As most endoliths are autotrophs, they can generate organic compounds essential for their survival on their own from inorganic matter. Inevitably, some endoliths have specialized in feeding on their autotroph relatives. The micro-biotope where these different endolithic species live together is called SLiME (Subsurface Lithotrophic Microbial Ecosystem).^[6] Green (from chlorophyll) fronds of a maidenhair fern: a photoautotroph Flowchart to determine if a species is autotroph, heterotroph, or a subtype An autotroph (from the Greek autos = self and trophe = nutrition) is an organism that produces organic compounds from carbon dioxide as a carbon source, using either light or... A biotope is an area of uniform environmental (physical) conditions providing habitat(s) for a specific assemblage of plants and animals. ...

See also

• Lithotroph
• The controversial Deep biogenic petroleum theory proposes that petroleum is produced by endolithic bacteria, and not decaying organic matter

A lithotroph is a microorganism which uses an inorganic substrate to synthesize all its organic molecules. ... This article or section does not cite its references or sources. ... Pumpjack pumping an oil well near Sarnia, Ontario Ignacy Łukasiewicz - inventor of the refining of kerosene from crude oil. ...

References

1. ^ Two miles underground — Gold mines present "ideal environment" for geologists studying subsurface microbes
2. ^ ^a b Looking for life in all the wrong places — research on cryptoendoliths Discover, May, 1997 by Will Hively
3. ^ Microbial Diversity of Cryptoendolithic Communities from the McMurdo Dry Valleys, Antarctica
4. ^ Glass Munchers Under the Sea — NASA Astrobiology Institute — Leslie Mullen
5. ^ Microbial Populations in Ocean Floor Basalt: Results from ODP Leg 187
6. ^ Frequently Requested Information about the SLiME Hypothesis

Discover is a science magazine that publishes articles about science for a general audience. ...

External links

• Endoliths General Collection — This collection of online resources such as news articles, web sites, and reference pages provides a comprehensive array of information about endoliths.
• Endolith Advanced Collection — Compiled for professionals and advanced learners, this endolith collection includes online resources such as journal articles, academic reviews, and surveys.