Snottite, also snoticle, is a
microbial mat
A microbial mat is a multi-layered sheet of microorganisms, mainly bacteria and archaea, or bacteria alone. Microbial mats grow at interfaces between different types of material, mostly on submerged or moist surfaces, but a few survive in deserts ...
of
single-celled extremophilic
An extremophile (from Latin ' meaning "extreme" and Greek ' () meaning "love") is an organism that is able to live (or in some cases thrive) in extreme environments, i.e. environments that make survival challenging such as due to extreme tempe ...
bacteria
Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of prokaryotic microorganisms. Typically a few micrometr ...
which hang from the walls and ceilings of
cave
A cave or cavern is a natural void in the ground, specifically a space large enough for a human to enter. Caves often form by the weathering of rock and often extend deep underground. The word ''cave'' can refer to smaller openings such as sea ...
s and are similar to small
stalactites, but have the consistency of
nasal mucus
The nasal mucosa lines the nasal cavity. It is part of the respiratory mucosa, the mucous membrane lining the respiratory tract. The nasal mucosa is intimately adherent to the periosteum or perichondrium of the nasal conchae. It is continuous wit ...
. In the
Frasassi Caves in Italy, over 70% of cells in Snottite have been identified as ''
Acidithiobacillus thiooxidans
''Acidithiobacillus thiooxidans'', formerly known as ''Thiobacillus thiooxidans'' until its reclassification into the newly designated genus ''Acidithiobacillus'' of the Acidithiobacillia subclass of Pseudomonadota, is a Gram-negative, rod-shaped ...
'', with smaller populations including an
archaeon
Archaea ( ; singular archaeon ) is a domain of single-celled organisms. These microorganisms lack cell nuclei and are therefore prokaryotes. Archaea were initially classified as bacteria, receiving the name archaebacteria (in the Archaebact ...
in the uncultivated 'G-plasma' clade of
Thermoplasmatales
In taxonomy, the Thermoplasmatales are an order of the Thermoplasmata. All are acidophiles, growing optimally at pH below 2. ''Picrophilus'' is currently the most acidophilic of all known organisms, being capable of growing at a pH of -0.06. M ...
(>15%) and a bacterium in the
Acidimicrobiaceae family (>5%).
The bacteria derive their energy from
chemosynthesis
In biochemistry, chemosynthesis is the biological conversion of one or more carbon-containing molecules (usually carbon dioxide or methane) and nutrients into organic matter using the oxidation of inorganic compounds (e.g., hydrogen gas, hydrog ...
of volcanic
sulfur compounds including
H2S and warm-water solution dripping down from above, producing
sulfuric acid. Because of this, their waste products are highly acidic (approaching pH=0), with similar properties to
battery acid
Sulfuric acid (American spelling and the preferred IUPAC name) or sulphuric acid ( Commonwealth spelling), known in antiquity as oil of vitriol, is a mineral acid composed of the elements sulfur, oxygen and hydrogen, with the molecular f ...
. 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 formed from
carbon dioxide
Carbon dioxide ( chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is trans ...
dissolved in water.
Snottites were brought to attention by researchers
Diana Northup and
Penny Boston studying them (and other organisms) in a toxic
sulfur cave called
Cueva de Villa Luz
Cueva de Villa Luz (English: Cave of the Lighted House), also known as Cueva del Azufre and Cueva de las Sardinas, is a cave near Tapijulapa in the southern Mexican state of Tabasco. The springs within the cave are rich in hydrogen sulfide, a g ...
(''Cave of the Lighted House''), in
Tabasco
Tabasco (), officially the Free and Sovereign State of Tabasco ( es, Estado Libre y Soberano de Tabasco), is one of the 32 Federal Entities of Mexico. It is divided into 17 municipalities and its capital city is Villahermosa.
It is located in ...
,
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
. 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
''Wonders of the Solar System'' is a 2010 television series co-produced by the BBC and Science Channel, and hosted by physicist Brian Cox. ''Wonders of the Solar System'' was first broadcast in the United Kingdom on BBC Two on 7 March 2010. The ...
'' 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 proof of past or present life has been found on Mars. Cumulative evidence suggests that during the ...
, it may be similarly primitive and hidden beneath the surface of the
Red Planet.
See also
*
Archaea
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
Speleothems
Sulphophiles
Cave organisms