Chroococcidiopsis
Classification
Bacteria; Cyanobacteria; Cyanophyceae; Chroococcales; Xenococcaceae NCBI link to find]
Species
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NCBI: Taxonomy |
Chroococcidiopsis thermalis, Chroococcidiopsis gigantea
Description and Significance
Chroococcidiopsis is a primitive, unicellular cyanobacteria. It can survive in a diverse array of extreme conditions. They can survive under extreme temperatures or pHs, high levels of radiation, high concentrations of salt, and arid environments. [5] It is an important microorganism to study due to their survival in harsh conditions. Their by products are oxygen which has contributed to our atmosphere as well as neurotoxins that can contaminate drinking water.
Genome Structure
Chroococcidiopsis thermails genome is one chromosome contains 6.69 megabase pairs (Mbp) made up of 6,033 genes as well as containing 5,752 encoding proteins. [6] The genome has a G+C makeup of 44.4%. [6]
Cell Structure, Metabolism and Life Cycle
Chroococcidiopsis is a negative gram, spherical cyanobacteria. It is prokaryotic meaning it lacks a nucleus. Chroococcidiopsis performs oxygenic photosynthesis. It is nitrogen fixing producing ammonia, nitrites, or nitrates. Heterocysts are commonly formed in low concentrations of nitrogen. Chroococcidiopsis sp. TS-821 differ from other cyanobacteria by forming tetrameric or dimeric Photosystem I reactions centers rather than the usual trimmeric complexes most cyanobacteria have [1]. The average cell has a diameter of 2-6 μm and is surround by thin, colorless, extracellular polysaccharide sheathes.They have a high desiccation tolerance due to the EPS that surround them.Thylakoid distributions are irregular throughout the cell. They are rarely found solitary, usually living in less spherical colonies. Cells are sometimes gathered in free-living agglomerations.Cell division occurs in two different ways, by either binary division in different planes or by irregular cell division (Geitler).
Ecology and Pathogenesis
Due to its primitive nature, it is thought that Chroococcidiopsis was a major contributor in transforming our atmosphere by releasing oxygen as a byproduct that accumulated and leading to a more oxidizing environment. Another implication of Chroococcidiopsis is its ability to produce neurotoxic by products such as β-N-methylamino-L-alanine that can create a health hazard for drinking water, particularly in underdeveloped countries. This can lead to malfunctioning of the nervous systems and in severe cases death. Chroococcidiopsis is currently thought to be one of the only microbes that would be capable of surviving in Mars' extreme environmental conditions. The possibility of farming Chroococcidiopsis to produce organic material to create soil and add oxygen to its atmosphere may one day be able to create conditions suitable for farming and life on Mars.
References
[1] Meng, L., Semchonok, D., Boekema. ““Characterization and Evolution of Tetrameric Photosystem I from the Thermophilic Cyanobacterium Chroococcidiopsis sp TS-821”. “The Plant Cell”. March 2014.]
[2] Billi, D., Friedmann, E., Helm, R., Potts, M. “”Gene Transfer to the Desiccation-Tolerant Cyanobacterium Chroococcidiopsis”. “Journal of Bacteriology”. 2001. Volume 183. p. 2298-2305.]
[3] NASA. “Greening of the Red Planet”. “National Aeronautics and Space Administration.” January 2001.]
[4] Geitler, L. “Chroococcopsis.”]
[5] Magana-Arachchi, M. Wanigatunge, R.P. “First report of genus Chroococcidiopsis (cyanobacteria) from Sri Lanka: a potential threat to human health”. Journal of the National Science Foundation”. 2013. Volume 41. P. 65-68.]
[6] ”Chroococcidiopsis thermalis.”]
Author
Page authored by Lauren Pifer, student of Prof. Jay Lennon at IndianaUniversity.
