Sulfolobaceae are a
family of the
Sulfolobales
In taxonomy, the Sulfolobales are an order of the Thermoprotei.
Phylogeny
The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN) and National Center for Biotechnology Information (NCBI)
...
belonging to the
domain Archaea
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 Archaebac ...
. The family consists of several genera adapted to survive environmental niches with extreme temperature and low pH conditions.
Ecology
''Sulfolobaceae'' species are
thermophiles, commonly found in
hot springs,
hydrothermal vent
A hydrothermal vent is a fissure on the seabed from which geothermally heated water discharges. They are commonly found near volcanically active places, areas where tectonic plates are moving apart at mid-ocean ridges, ocean basins, and hotspot ...
s,
mudpots, and volcanically active regions, with ''
Sulfolobus
''Sulfolobus'' is a genus of microorganism in the family Sulfolobaceae. It belongs to the archaea domain.
''Sulfolobus'' species grow in volcanic springs with optimal growth occurring at pH 2-3 and temperatures of 75-80 °C, making them ...
'' genus found almost anywhere with volcanic activity. ''Sulfolobaceae'' are found in temperatures ranging from 40 to 95 °C. They are found in pH levels between 1 and 6 which makes specific species
acidophiles.
Certain species, like
''Metallosphaera prunae'', have been found living on smoldering waste material from mines by utilizing a lithoautotrophic metabolism.
''Sulfolobaceae'' are involved in
biofilm formation. Analysis of biofilms produced by different species has shown very few regulating
proteins in common between these species, thus indicating that multiple different regulatory mechanisms for biofilm formation may exist. ''
Sulfolobus acidocaldarius'' has been observed forming tower-like biofilm structures and ''Sulfolobus solfataricus'' has been observed forming carpet-like biofilms.
Metabolism
''Sulfolobaceae'' species exhibit a diverse range of metabolisms including
aerobic, facultative
anaerobic, or obligate anaerobic with
chemoheterotrophic,
lithoautotrophic, or
mixotrophic lifestyles. Some species exhibit
metabolic flexibility, being able to use several different metabolic pathways depending on the available energy sources, while others have a narrow range of metabolic options.
Chemoheterotrophic ''Sulfolobaceae'' gain their energy by
oxidizing reduced organic carbon compounds, including
D-glucose,
D-galactose, other common sugars,
amino acids, and other complex molecules, using oxidized forms of
sulfur
Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula ...
. Lithoautotrophic metabolism, on the other hand, involves gaining energy from the oxidation of reduced compounds such as elemental sulfur, sulfur ores, and other reduced sulfur compounds, or molecular hydrogen.
''Sulfolobaceae'' prefer low sodium chloride environments, with the exception of the ''Acidianus'' genus.
Glycogen
Glycogen is a multibranched polysaccharide of glucose that serves as a form of energy storage in animals, fungi, and bacteria. The polysaccharide structure represents the main storage form of glucose in the body.
Glycogen functions as one o ...
is used as long-term carbon and energy storage.
Morphological characteristics
''Sulfolobaceae'' species have regular, irregular, or lobed
cocci cell shapes. Their size falls between 0.5 and 2 μm in diameter. Several different surface appendages have been observed, including
archaella
The archaellum (; formerly archaeal flagellum) is a unique structure on the cell surface of many archaea, that allows for swimming motility. The archaellum consists of a rigid helical filament that is attached to the cell membrane by a molecular ...
in motile species, typically expressed upon starvation.
Unique to ''Sulfolobus acidocaldarious'' are the archaeal adhesive pili which are important for surface attachment in biofilm formation. Archaeal type IV pilin surface appendage expression occurs through a dedicated type IV prepilin signal peptidase before filaments can be assembled.
A sugar-binding surface structure termed bindosome has been found in ''Sulfolobus solfataricus''. When assembled into a dedicated bindosome assembly system they are active in the transport of sugars.
Proteinaceous toxins termed sulfolobicins, have been produced by certain strains of ''Sulfolobus islandicus''. These toxins may provide a competitive advantage, as they inhibit the growth of non-toxin producing strains of ''S. islandicus'' and certain other ''Sulfolobus'' species. Other species, such as ''Sulfolobus acidocaldarius'', are not inhibited. The
gene encoding for sulfolobicins have been identified in other ''Sulfolobus'' species.
Phylogeny
The currently accepted taxonomy is based on the
List of Prokaryotic names with Standing in Nomenclature (LPSN)
and
National Center for Biotechnology Information (NCBI)
References
Further reading
Journals
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Books
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Databases
External links
{{Taxonbar, from=Q7636207
Archaea taxonomic families
Thermoproteota
es:Sulfolobaceae