Snottite, also snoticle, is a
microbial mat of
single-celled extremophilic bacteria
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micr ...
which hang from the walls and ceilings of
cave
Caves or caverns are natural voids under the Earth's Planetary surface, surface. Caves often form by the weathering of rock and often extend deep underground. Exogene caves are smaller openings that extend a relatively short distance undergrou ...
s and are similar to small
stalactite
A stalactite (, ; , ) is a mineral formation that hangs from the ceiling of caves, hot springs, or man-made structures such as bridges and mines. Any material that is soluble and that can be deposited as a colloid, or is in suspension (chemistry ...
s, but have the consistency of
nasal mucus. In the
Frasassi Caves in Italy, over 70% of cells in Snottite have been identified as ''
Acidithiobacillus thiooxidans'', with smaller populations including an
archaeon in the uncultivated 'G-plasma' clade of
Thermoplasmatales
Thermoplasmatales is an order (biology), order of archaeans in the class Thermoplasmata. All are acidophiles, growing optimally at pH below 2. ''Picrophilus'' is currently the most acidophile, acidophilic of all known organisms, being capable of ...
(>15%) and a bacterium in the
Acidimicrobiaceae family (>5%).
The bacteria derive their energy from
chemosynthesis of volcanic
sulfur
Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...
compounds including
H2S and warm-water solution dripping down from above, producing
sulfuric acid
Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid (English in the Commonwealth of Nations, Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen, ...
. Because of this, their waste products are highly acidic (approaching pH=0), with similar properties to
battery acid. Researchers at the University of Texas have suggested that this sulfuric acid may be a more significant cause of cave formation than the usual explanation offered of the
carbonic acid
Carbonic acid is a chemical compound with the chemical formula . The molecule rapidly converts to water and carbon dioxide in the presence of water. However, in the absence of water, it is quite stable at room temperature. The interconversion ...
formed from
carbon dioxide
Carbon dioxide is a chemical compound with the chemical formula . It is made up of molecules that each have one carbon atom covalent bond, covalently double bonded to two oxygen atoms. It is found in a gas state at room temperature and at norma ...
dissolved in water.
Snottites were brought to attention by researchers
Diana Northup and
Penny Boston studying them (and other organisms) in a toxic
sulfur
Sulfur ( American spelling and the preferred IUPAC name) or sulphur ( Commonwealth spelling) is a chemical element; it has symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms ...
cave called
Cueva de Villa Luz (''Cave of the Lighted House''), in
Tabasco
Tabasco, officially the Free and Sovereign State of Tabasco, is one of the Political divisions of Mexico, 32 Federal Entities of Mexico. It is divided into Municipalities of Tabasco, 17 municipalities and its capital city is Villahermosa.
It i ...
,
Mexico
Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...
. Snottites were first discovered in this cave by Jim Pisarowicz in 1986, who also coined the term.
[Michael Ray Taylor, ''Dark Life: Martian Nanobacteria, Rock-eating Cave Bugs, and Other Extreme Organisms of Inner Earth and Outer Space'', pp. 56–57, Simon and Schuster, 1999 .]
The BBC series ''
Wonders of the Solar System'' saw
Professor Brian Cox examining snottites and positing that if there is
life on Mars
The possibility of life on Mars is a subject of interest in astrobiology due to the planet's proximity and similarities to Earth. To date, no conclusive evidence of past or present life has been found on Mars. Cumulative evidence suggests that ...
, it may be similarly primitive and hidden beneath the surface of the
Red Planet.
See also
*
Archaea
Archaea ( ) is a Domain (biology), domain of organisms. Traditionally, Archaea only included its Prokaryote, prokaryotic members, but this has since been found to be paraphyletic, as eukaryotes are known to have evolved from archaea. Even thou ...
References
Additional sources
Hose L. D., Pisarowicz J. A. (1999
"Cueva de Villa Luz, Tabasco, Mexico: reconnaissance study of an active sulfur spring cave and ecosystem" ''J Cave Karst Studies''; 61:13–21
External links
at NASA
The Subsurface Life in Mineral Environments (SLIME) Team
{{Extremophile
Cave organisms
Speleothems
Sulphophiles