Syntrophus aciditrophicus
Classification
Domain: Bacteria
Phylum: Proteobacteria;
Class : Deltaproteobacteria;
Order : Syntrophobacterales;
Family: Syntrophaceae
Species
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NCBI: [[1] link to find]] |
Syntrophus aciditrophicus
Description and Significance
S.aciditrophicus is an anaerobic, gram-negative, non-motile, non-spore forming, rod-shaped bacterium. Genes for synthesis of Type IV pili, complete flagella synthesis and chemosensory genes are present. It is a benzoate-degrading bacterium able to degrade fatty acid chains in a symbiotic relationship with methanogens. It has been previously isolated from sewage sludge and can be found in anaerobic environments. it is an organism that has metabolic genes to degrade aromatic and alicyclic compounds and synthesize APT from acetyl CoA and produces hydrogen. The unique metabolism of syntrophic fatty and aromatic acids of S. aciditrophicus makes this organism stand out from almost all other organisms. Although little information is known about the metabolism of syntrophs, such as S. aciditrophicus , they constitute the missing link in understanding the anaerobic flow of carbon in the biosphere.The unique metabolic pathway that "S. aciditrophicus has makes scientist think it can be part of anaerobic hydrogen production from biomass.
Genome Structure
The ‘’S. aciditrophicus’’ genome is the smallest among all δ-proteobacteria that has ever been discovered.‘’S. aciditrophicus’’ have single circular chromosome and contains 3,179,300 base pairs and have an average of 51.46% of G+C contents, 3169 genes were identified. The genome of ‘’S. aciditrophicus’’ contains genes that encodes for proteins that function as a protection from oxidative stress, these proteins includes peroxiredoxin, (‘’S’’)-2- hydroxy-acid oxidases, Fe-Mn superoxide dismutase, thioredoxin and catalase. For an obligate anaerobe there weren’t any genes identified for superoxide reductase system in ‘’S. aciditrophicus’’. There were few genes that encode got efflux pumps which in turn deals with metal resistance and antimicrobial compounds. The analysis of the ‘’S. aciditrophicus’’ genomes showed genes encodes for small heat shock protein and chaperones. Also, five genes found that encodes for cold shock proteins, also two genes were found that encodes for the universal stress protein. Few identified genes encodes for solvent and acid stress response proteins. (McInerney, et. al.; Jackson, et. al.)
Cell Structure, Metabolism and Life Cycle
Interesting features of cell structure; how it gains energy; what important molecules it produces.
S. aciditrophicus’s genome has genes required for synthesis of Type IV pili. These pili may facilitate cell-to-cell attachment to facilitate the transfer of hydrogen and other chemical compound to its syntrophic partners. Although it has a complete set of flagella, structural proteins and chemosensory genes, motility and chemotaxis have yet to be observed in laboratory cultures.
S. aciditrophicus’s genome shows limited metabolic options to use any amino acids and carbohydrates for energy conservation. The genome does not contains any carbohydrate transporters, and amino acid and small peptide transporters are very liminted. The ability for S. aciditrophicus’s metabolism to break down fatty acid and aromatic compounds are heavily reliant on syntrophic relationship with other organisms. It’s genome has an incomplete tricaroboxylic acid cycle.
Ecology and Pathogenesis
Habitat; symbiosis; biogeochemical significance; contributions to environment.
If relevant, how does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
References
Biopact. (2007, April 20). Extremophile’s genome sequenced, may improve biohydrogen production. [Nature Blog Network]. Retrieved from http://news.mongabay.com/bioenergy/2007/04/extremophiles-genome-sequenced-may-lead.html
Jackson, B. E., Bhupathiraju, V. K., Tanner, R. S., Woese, C. R. and McInerney, M. J. (1999). Syntrophus aciditrophicus sp. nov., a new anaerobic bacterium that degrades fatty acids and benzoate in syntrophic association with hydrogen-using microorganisms. Arch Microbiol, 171, 107-114
Kim, M., Buckel, W., Le, H., & McInerney, M. (2013). Identification and characterization of re-citrate synthase in Syntrophus aciditrophicus. Journal Of Bacteriology, 195(8), 1689-1696. doi:10.1128/JB.02185-12
McInerney, M. J., Rohlin, L., Mouttaki, H., Kim, U., Krupp, R. S., Rios-Hernandez, L., & ... Gunsalus, R. P. (2007). The Genome of Syntrophus aciditrophicus: Life at the Thermodynamic Limit of Microbial Growth. Proceedings of the National Academy of Sciences of the United States of America, (18). 7600.
Stams, A. J. M., Sousa, D. Z., Kleerebezem, R. and Plugge, C. M. (2012). Rold of syntrophic microbial communities in high-rate methanogenic bioreactors. Water Science & Technology, 66(2), 352-362.
Author
Page authored by _____, student of Prof. Jay Lennon at IndianaUniversity.
