Prochlorophyta Explained

Prochlorophyta is a group of photosynthetic bacteria, an important component of picoplankton.^[1] These oligotrophic organisms are abundant in nutrient poor tropical waters and use a unique photosynthetic pigment, divinyl-chlorophyll, to absorb light and acquire energy.^{[2] [3]} 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^[4] and off the coast of Mexico (Prochloron).^[5] Prochlorophyta was soon assigned as a new algal sub-class in 1976 by Ralph A. Lewin of the Scripps Institution of Oceanography.^{[6] [7]} Other phytoplankton that lacked phycobilin pigments were later found in freshwater lakes in the Netherlands by Tineke Burger-Wiersma and colleagues^[8] and were termed Prochlorothrix (additional reading on Prochlorothrix can be found in a journal article by A.V. Pinevich ^[9]). In 1986 Prochlorococcus was found by Sallie W. (Penny) Chisholm and colleagues.^[10] Prochlorococcus 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). They morphologically resemble Cyanobacteria (formally known as Blue Green Algae). Members of Prochlorophyta have been found as coccoid (spherical) (Coccus) shaped, as in Prochlorococcus, and as filaments, as in Prochlorothrix.

See also

• Cyanobacteria
• Prochloron
• Prochlorococcus
• Photosynthetic picoplankton

External links

• Prochlorophytes

Notes and References

1. Book: Miller, Charles B.. Biological Oceanography. 2004. Wiley-Blackwell.
2. Lewin. Ralph A.. Prochlorophyta - a matter of class distinctions. Photosynthesis Research. 2002. 73. 59–61. 16245104. 10.1023/A:1020400327040.
3. Partensky. Frederic. Nicolas Hoepffner . William K.W. Li . Osvaldo Ulloa . Daniel Vaulot . Photoacclimation of Prochlorococcus sp. (Prochlorophyta) Strains Isolated from the North Atlantic and the Mediterranean Sea. Plant Physiol.. 1993. 101. 285–296. 10.1104/pp.101.1.285 . 12231684. 158675.
4. Newcomb. Eldon H.. Thomas D. Pugh. Blue-green algae associated with ascidians of the Great Barrier Reef. Nature. 1975. 253. 533–534. 10.1038/253533a0.
5. Lewin. Ralph A.. A marine Synechocystis (Cyanophyta, Chroococcales) epizoic on ascidians. Phycologia. 1975. 14. 3. 153–160. 10.2216/i0031-8884-14-3-153.1.
6. Lewin. Ralph A.. Prochlorophyta as a proposed new division of algae. Nature. 1976. 261. 697–698. 10.1038/261697b0.
7. Lewin. Ralph A.. Prochloron, type genus of the Prochlorophyta. Phycologia. 1977. 16. 2. 217. 10.2216/i0031-8884-16-2-217.1.
8. Burger-Wiersma. T.. Veenhuis. M.. Korthals. H.J.. Van de Wiel. C.C.M.. Mur. L.R.. A new prokaryote containing chlorophylls a and b. Nature. 1986. 320. 262–264. 10.1038/320262a0 .
9. Pinevich. AV . Kulberg, OM . Matthijs, HCP . Schubert, H. . Willen, E. . Gavrilova, OV . Velichko, N.. Characterization of a novel chlorophyll b-containing Prochlorothrix species (Prochlorophyta) and its photosynthetic apparatus. Microbios. 1999. 100. 159–174.
10. Chisholm. S.W. . Olson, R.J. . Zettler, E.R. . Goericke, R. . Waterbury, J.B. . Welschmeyer, N.A.. A novel free-living prochlorophyte abundant in the oceanic euphotic zone. Nature. 1988. 334. 340–343. 10.1038/334340a0.