Chlorobium

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Chlorobium
Scientific classification
Kingdom: Bacteria
Phylum: Chlorobi
Class: Chlorobia
Order: Chlorobiales
Family: Chlorobiaceae
Genus: Chlorobium
Some species

C. clathratiforme

C. limicola

C. phaeobacteroides

C. tepidum

Chlorobium is a genus of green sulfur bacteria. They are photolithotrophic oxidizers of sulfur and most notably utilise a noncyclic electron transport chain to reduce NAD+. Hydrogen sulfide is used as an electron source and carbon dioxide its carbon source.[1]

Chlorobium species exhibit a dark green color; in a Winogradsky column, the green layer often observed is composed of Chlorobium. This genus lives in strictly anaerobic conditions below the surface of a body of water, commonly the anaerobic zone of a eutrophic lake.[1]

The complete C. tepidum genome, which consists of 2.15 megabases (Mb), has recently been published.[2] It synthesizes chlorophyll a and bacteriochlorophylls (BChls) a and c, of which the model organism has been used to ellucidate the biosynthesis of BChl c.[3] Several of its carotenoid metabolic pathways (including a novel lycopene cyclase) have similar counterparts in cyanobacteria.[4][5]

References

  1. 1.0 1.1 Prescott, Harley, Klein. (2005). Microbiology pp. 195, 493, 597, 618-619, 339.
  2. J.A. Eisen (2002). "The complete genome sequence of the green sulfur bacterium Chlorobium tepidum". Proc. Natl Acad. Sci. USA. 99: 9509–9514.
  3. N.-U Frigaard; et al. (2006). B. Grimm et al., eds, ed. Chlorophylls and Bacteriochlorophylls: Biochemistry, Biophysics, Functions and Applications. 25. Springer. pp. Vol. 25, pp. 201-221.
  4. N.-U. Frigaard; et al. (2004). "Genetic manipulation of carotenoid biosynthesis in the green sulfur bacterium Chlorobium tepidum". Proc. Natl Acad. Sci. USA. 186: 5210–5220.
  5. J.A. Maresca; et al. (2005). A. van der Est & D. Bruce, eds, ed. Photosynthesis: Fundamental Aspects to Global Perspectives. Allen Press. pp. 884–886.

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