Candidatus ruthia magnifica: Difference between revisions

From MicrobeWiki, the student-edited microbiology resource
Line 29: Line 29:


==Ecology==
==Ecology==
''R. magnifica'' lives in the gill tissues of ''C. magnifica'' and is transmitted vertically between generations through the clam’s eggs.[4] ''R. magnifica'' provides nutrition for its host, ''C. magnifica'', by oxidizing sulfur in hydrothermal vents. Because ''R. magnifica'' can fix carbon through the calvin cycle, environmental Carbon dioxide can be converted into a more bioavailable form that can be distributed throughout the environment when ''R. magnifica'' is eventually digested by its host [6].  
''R. magnifica'' lives in the gill tissues of ''C. magnifica'' and is transmitted vertically between generations through the clam’s eggs[4]. ''R. magnifica'' provides nutrition for its host, ''C. magnifica'', by oxidizing sulfur in hydrothermal vents[5]. Because ''R. magnifica'' can fix carbon through the calvin cycle, environmental Carbon dioxide can be converted into a more bioavailable form that can be distributed throughout the environment when ''R. magnifica'' is eventually digested by its host [6].  





Revision as of 22:25, 3 June 2007

A Microbial Biorealm page on the genus Candidatus ruthia magnifica

Classification

Higher order taxa

Bacteria(Kindgdom); Proteobacteria(Phylum); Gammaproteobacteria(Class); sulfur-oxidizing symbionts(order)[NCBI, [1]]

Species

NCBI: Taxonomy

Candidatus Ruthia magnifica

Description and significance

R. magnifica is a chemoautotrophic bacteria that lives symbiotically with a giant clam, a Metazoan with a genus and species of Calyptogena magnifica. It lives in an environment that may be characterized as a hydrothermal vent. It uses the chemical energy of reduced sulfur emanating from vents to provide their hosts with carbon and a large array of additional necessary nutrients such as essential amino acids and vitamins.[3] In return, the hosts provide the bacteria with inorganic substrates necessary for chemoautotrophic activity. R. magnifica itself lives in the gut and ciliary food groove of C. magnifica.[3] The sequencing of the R. magnifica genome is important in determining its metabolism and the compounds it is able to produce. Which, in turn, will give insight into the metabolism and biology of the host. R. magnifica is the first intracellular, sulfur-oxidizing endosymbiont to have its genome sequenced. It also has the largest genome of any intracellular symbiont sequenced to date and may represent an early intermediate in the evolution toward a chemoautotrophic organelle such as a chloroplast.[3]

Genome structure

R. magnifica has 1,119 genes which, in turn, encode 1,953 proteins. A single circular chromosome contains genes which are predicted to encode all the proteins necessary for all the metabolic pathways typical of free-living chemoautotrophs. Some of the major pathways are carbon fixation, sulfur oxidation, nitrogen assimilation, amino acid and cofactor/vitamin biosynthesis.[3]

Cell structure and metabolism

R. magnifica fixes carbon through the Calvin Cycle, with its genome encoding RuBisCo and phosphribulokinase. R. Magnifica gains energy by sulfur oxidation through sox(sulfur oxidation) and dsr (dissimilatory sulfite reductase) genes. When there is no environmental sulfur available, it may oxidize its sulfur granules through the use of dsr homologs. R. magnifica has the potential to produce 20 amino acids and 10 vitamins and cofactors. The genome encodes a complete glycolytic pathway and the nonoxidative branch of the pentose phosphate pathway. It also encodes a tricarboxylic acid (TCA) cycle, but lacks a critical enzyme needed to break down a substrate in the cycle called alpha-ketoglutarate dehydrogenase. The lack of this enzyme has been suggested to indicate obligate autotrophy in other bacteria, allowing them to fix carbon dioxide when no other substrates are available as a carbon source. In order to gain energy via reduction, R. magnificauses an electron transport chain that is relatively simple when compared to other microbes. It is thought that a reduced quinone transfers electrons to cytochrome c via a bc1 complex, and a terminal cytochrome c then transfers these electrons to oxygen. The energy derived from the transfer of electrons can be used to make ATP. The R. magnifica genome also encodes proteins that are necessary for two nitrogen assimilation pathways. Nitrate and ammonia are transported inside the cell through the nitrate or nitrite transporter, respectively. Those compounds are then reduced via nitrate and nitrite reductase enzymes and incorporated into the cell via glutamine synthetase and glutamate synthase. R. magnifica not only uses nitrogen available from the vents, it also recycles the host's amino acid waste.[3]

Ecology

R. magnifica lives in the gill tissues of C. magnifica and is transmitted vertically between generations through the clam’s eggs[4]. R. magnifica provides nutrition for its host, C. magnifica, by oxidizing sulfur in hydrothermal vents[5]. Because R. magnifica can fix carbon through the calvin cycle, environmental Carbon dioxide can be converted into a more bioavailable form that can be distributed throughout the environment when R. magnifica is eventually digested by its host [6].



Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.

Pathology

Due to its need for sulfer and its niche of hydrothermic vents, it is not likely to find R. magnifica in the same environment as humans. Therefore, it is not considered a pathogen and is not currently thought to cause any disease.

Application to Biotechnology

No known compounds that are useful in the Biotechnology are produced by R. magnifica

Current Research

Enter summaries of the most recent research here--at least three required

References

[2]] NCBI Taxonomy

[3] LG Newton, T. Woyke, "The Calyptogena magnifica Chemoautotrophic Symbiont Genome". Science. 2007. Volume 315. p. 998.

[4] C. M. Cavanaugh, J. J. Robinson, "vertical transmission of chemoautotrophic symbionts". biol. bull. 1996. volume 190. p. 195.

[5] Luis A. Hurtado, Mariana Mateos, Richard A. Lutz and Robert C. Vrijenhoek "Coupling of Bacterial Endosymbiont and Host Mitochondrial Genomes in the Hydrothermal Vent Clam Calyptogena magnifica" APPLIED AND ENVIRONMENTAL MICROBIOLOGY, Apr. 2003, Vol. 69, No. 4 p. 2058–2064

[6] A. Fiala-Médioni, C. Métivier, A. Herry, M. Le Pennec, Mar. Biol. 92, 65 (1986)

Edited by Albert Noniyev, student of Rachel Larsen and Kit Pogliano