Acaryochloris marina

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Acaryochloris marina
Scientific classification
Kingdom: Bacteria
Phylum: Cyanobacteria
Family: unclassified
Genus: Acaryochloris
Species: Acaryochloris marina
Chlorophyll d

Acaryochloris marina is a symbiotic species of the phylum Cyanobacteria that produces Chlorophyll d, allowing it to utilise far-red light, at 710 nm wavelength.[1]

Description[edit]

It was first discovered in 1993 from coastal isolates of coral in the Republic of Palau in the west Pacific Ocean and announced in 1996.[2] Despite the claim on the 1996 Nature paper that its formal description was to be published shortly thereafter,[2] a tenatitive partial description was presented in 2003 due to phylogenetic issues (deep branching cyanobacterium).[3]

Genome[edit]

Its genome was sequenced in 2008, revealing a large bacterial genome of 8.3 Mb with 9 plasmids.[1]

Etymology[edit]

The name Acaryochloris is a combination of the Greek prefix a (ἄν)[4] meaning "without", the (neuter) noun caryo (κάρυον)[5] meaning "nut" (here intended as "nucleus") and the adjective chloros (χλωρός)[6] meaning "green" (or more correctly the feminine Neolatin noun N.L. chloris);[7] therefore the medieval Latin [sic. in,[3] it is Neolatin] feminine noun Acaryochloris means "without nucleus green".[3] The specific epithet marina is a Latin feminine adjective meaning "marine".[3]

Classification[edit]

Main article: Cyanobacteria

Due to historical reason, the classification of Cyanobacteria is problematic and many cyanobacteria are not validly published, meaning they have not yet been placed into the classification framework.[8] One of these not officially recognised species is Acaryochloris marina, which technically should be written as "Acaryochloris marina" in official writings, but in effect this is rarely done (cf.[1][9])

Exoplanet Habitability[edit]

Scientists including NASA's Nancy Kiang have proposed that the existence of Acaryochloris marina suggests that organisms that use Chlorophyll d, rather than Chlorophyll a, may be able to perform oxygenic photosynthesis on exoplanets orbiting red dwarf stars (which emit much less light than the Sun).[10][11] Because approximately 70 percent of the stars in the Milky Way galaxy are red dwarfs,[12] the existence of Acaryochloris marina implies that oxygenic photosynthesis may be occurring on far more exoplanets than astrobiologists initially thought possible.

See also[edit]

References[edit]

  1. ^ a b c Swingley, W. D.; Chen, M.; Cheung, P. C.; Conrad, A. L.; Dejesa, L. C.; Hao, J.; Honchak, B. M.; Karbach, L. E.; Kurdoglu, A.; Lahiri, S.; Mastrian, S. D.; Miyashita, H.; Page, L.; Ramakrishna, P.; Satoh, S.; Sattley, W. M.; Shimada, Y.; Taylor, H. L.; Tomo, T.; Tsuchiya, T.; Wang, Z. T.; Raymond, J.; Mimuro, M.; Blankenship, R. E.; Touchman, J. W. (2008). "Niche adaptation and genome expansion in the chlorophyll d-producing cyanobacterium Acaryochloris marina". Proceedings of the National Academy of Sciences 105 (6): 2005–2010. doi:10.1073/pnas.0709772105. PMC 2538872. PMID 18252824.  edit
  2. ^ a b H. Miyashita, H. Ikemoto, N. Kurano, K. Adachi, M. Chihara and S. Miyachi (1996). "Chlorophyll d as a major pigment". Nature 383 (6599): 402. doi:10.1038/383402a0. 
  3. ^ a b c d Miyashita, H.; Ikemoto, H.; Kurano, N.; Miyachi, S.; Chihara, M. (2003). "Acaryochloris Marina Gen. Et Sp. Nov. (Cyanobacteria), an Oxygenic Photosynthetic Prokaryote Containing Chl D As a Major Pigment1". Journal of Phycology 39 (6): 1247–1253. doi:10.1111/j.0022-3646.2003.03-158.x.  edit
  4. ^ ἄν. Liddell, Henry George; Scott, Robert; A Greek–English Lexicon at the Perseus Project
  5. ^ κάρυον. Liddell, Henry George; Scott, Robert; A Greek–English Lexicon at the Perseus Project
  6. ^ χλωρός. Liddell, Henry George; Scott, Robert; A Greek–English Lexicon at the Perseus Project
  7. ^ Gender of suffices entry in LPSN [Euzéby, J.P. (1997). "List of Bacterial Names with Standing in Nomenclature: a folder available on the Internet". Int J Syst Bacteriol 47 (2): 590–2. doi:10.1099/00207713-47-2-590. ISSN 0020-7713. PMID 9103655. ]
  8. ^ Classification of Cyanobacteria entry in LPSN [Euzéby, J.P. (1997). "List of Bacterial Names with Standing in Nomenclature: a folder available on the Internet". Int J Syst Bacteriol 47 (2): 590–2. doi:10.1099/00207713-47-2-590. ISSN 0020-7713. PMID 9103655. ]
  9. ^ Kühl, M.; Chen, M.; Ralph, P. J.; Schreiber, U.; Larkum, A. W. D. (2005). "Ecology: A niche for cyanobacteria containing chlorophyll d". Nature 433 (7028): 820–820. doi:10.1038/433820a.  edit
  10. ^ Gronstal, Aaron (February 2012). "Far-Out Photosynthesis". News & Features (NASA). Retrieved 26 January 2104. 
  11. ^ Mielke, S.P., N.Y. Kiang, R.E. Blankenship, M.R. Gunner, and D. Mauzerall (2011). "Efficiency of photosynthesis in a Chl d-utilizing cyanobacterium is comparable to or higher than that in Chl a-utilizing oxygenic species". BBA Bioenergetics 1807 (9): 1231–1236. doi:10.1016/j.bbabio.2011.06.007. 
  12. ^ "Colorful Dwarfs". StarDate. The University of Texas McDonald Observatory. Retrieved 23 January 2014.