Prochlorophyta is a group of photosynthetic

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 ...

, an important component of

picoplankton Picoplankton is the fraction of plankton composed by cells between 0.2 and 2 μm that can be either prokaryotic and eukaryotic phototrophs and heterotrophs: * photosynthetic * heterotrophic They are prevalent amongst microbial plankton communit ...

. These oligotrophic organisms are abundant in nutrient poor tropical waters and use a unique photosynthetic pigment, divinyl-chlorophyll, to absorb light and acquire energy. Prochlorophyta lack red and blue phycobilin pigments and have stacked thylakoids, making them distinctly different from Cyanobacteria (or Cyanophyta), but some authors consider them as part of the Cyanobacteria, as the group Prochlorales.

Discovery and naming

This unique group of phytoplankton, with no phycobilin pigments, were initially found in 1975 near the

Great Barrier Reef The Great Barrier Reef is the world's largest coral reef system composed of over 2,900 individual reefs and 900 islands stretching for over over an area of approximately . The reef is located in the Coral Sea, off the coast of Queensland, ...

and off the coast of Mexico (''

Prochloron ''Prochloron'' (from the Greek ''pro'' (before) and the Greek ''chloros'' (green) ) is a genus of unicellular oxygenic photosynthetic prokaryotes commonly found as an extracellular symbiont on coral reefs, particularly in didemnid ascidians (sea ...

''). Prochlorophyta was soon assigned as a new algal sub-class in 1976 by Ralph A. Lewin of the Scripps Institution of Oceanography. Other phytoplankton that lacked phycobilin pigments were later found in freshwater lakes in the Netherlands by Tineke Burger-Wiersma and colleagues and were termed ''Prochlorothrix'' (additional reading on ''Prochlorothrix'' can be found in a journal article by A.V. Pinevich ). In 1986 ''

Prochlorococcus ''Prochlorococcus'' is a genus of very small (0.6 μm) marine cyanobacteria with an unusual pigmentation ( chlorophyll ''a2'' and ''b2''). These bacteria belong to the photosynthetic picoplankton and are probably the most abundant photosynth ...

'' was found by Sallie W. (Penny) Chisholm and colleagues. ''

'' may be responsible for a significant portion of the global primary production.

Morphology

Prochlorophytes are very small microbes generally between 0.2 and 2 µm (

photosynthetic picoplankton Photosynthetic picoplankton or picophytoplankton is the fraction of the phytoplankton performing photosynthesis composed of cells between 0.2 and 2 µm in size ( picoplankton). It is especially important in the central oligotrophic regions of ...

). They morphologically resemble Cyanobacteria (formally known as

Blue Green Algae Cyanobacteria (), also known as Cyanophyta, are a phylum of gram-negative bacteria that obtain energy via photosynthesis. The name ''cyanobacteria'' refers to their color (), which similarly forms the basis of cyanobacteria's common name, blue ...

). Members of Prochlorophyta have been found as coccoid (spherical) (

Coccus A coccus (plural cocci) is any bacterium or archaeon that has a spherical, ovoid, or generally round shape. Bacteria are categorized based on their shapes into three classes: cocci (spherical-shaped), bacillus (rod-shaped) and spiral ( of whi ...

) shaped, as in ''

'', and as filaments, as in ''Prochlorothrix''.

References

External links

Prochlorophytes
{{Taxonbar, from=Q577485 Cyanobacteria

Discovery and naming

Morphology

See also

References

External links