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| {{Biorealm Genus}} | | {{Biorealm Genus}} |
| [[Image:060718_gold_bacteria_01.jpg|thumb|300px|right|'' Bacterial induced formation of Cd crystals by Ralstonia metallidurans on Zirfon M5 membranes in the continuous tubular membrane reactor.''. [http://images.livescience.com/images/060718_gold_bacteria_01.jpg]]]
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| ==Classification== | | ==Classification== |
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| Kingdom: Bacteria | | Kingdom: Bacteria |
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| Phylum: Proteobacteria | | Phylum: Proteobacteria |
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| Class: Beta Proteobacteria | | Class: Beta Proteobacteria |
| Order:Burkholderiales | | |
| | Order: Burkholderiales |
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| Family: Ralstoniaceae | | Family: Ralstoniaceae |
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| Genus: Ralstonia | | Genus: Ralstonia |
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| Species: R. metallidurans | | Species: R. metallidurans |
| Strain: CH3
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| | [Others may be used. Use [http://www.ncbi.nlm.nih.gov/Taxonomy/ NCBI] link to find] |
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| ===Species=== | | ===Species=== |
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| '''NCBI: [http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Tree&id=2&lvl=3&lin=f&keep=1&srchmode=1&unlock Taxonomy]''' | | '''NCBI: [http://www.ncbi.nlm.nih.gov/Taxonomy/Browser/wwwtax.cgi?mode=Tree&id=2&lvl=3&lin=f&keep=1&srchmode=1&unlock Taxonomy]''' |
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| Ralstonia solanacearum
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| Ralstonia oxalatica
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| Ralstonia paucula
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| Ralstonia pickettii
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| ''Genus species'' | | ''Genus species'' |
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| ==Description and significance== | | ==Description and significance== |
| | | Describe the appearance, habitat, etc. of the organism, and why it is important enough to have its genome sequenced. Describe how and where it was isolated. |
| The reference strain of Ralstonia Metallidurans, CH34, was first isolated in 1976 from the sludge of a zinc decantation tank in Belgium that was polluted with high concentrations of several heavy metals, it and other metal-resistant members of the genus Ralstonia are frequently found in sediments and soils with a high content of heavy metals from diverse geographical locations.
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| Alcaligenes eutrophus CH34, was just recently renamed Ralstonia. Ralstonia metallidurans is gram-negative, non-spore forming bacterium which thrives in the presence of millimolar concentrations of several heavy-metals; Zn, Cd, Co,Pb,Hg, Ni and Cr.
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| This extremophile is better able to withstand high concentrations of heavy metals than any other well-studied organism. This fact renders it a potential agent of bioremediation as well as an ideal model organism for understanding metal resistance phenotypes. Due to its survival in extreme metal concentrations and genomic sequencing it is thought to be one of the first life forms on earth, existing when there was very little oxygen in the atmosphere some 2.5 billion years ago.
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| ==Genome structure== | | ==Genome structure== |
| | | Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence? |
| Its genome is approximately 6800 kb in size. The heavy-metal resistance found in these bacteia is conferred by two large megaplasmids (pMOL28=180 kbp and pMOL30=240 kbp) carrying gene clusters that encode cation-efflux machinery spanning both bacterial membranes. These low-copy number plasmids are maintained in the presence or absence of selective pressure and are self-transferable at relatively low frequencies. The Minimal Inhibitory Concentration (MIC) for free, non-chelated Ni, Co, Zn and Cd are 2.5, 20, 12 and 2.5 mM, respectively for the reference strain.
| | Does it have any plasmids? Are they important to the organism's lifestyle? |
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| The genome of this bacterium contains also 8 P-type ATPase involved in metal efflux specialized in lead, cadmium, thallium and/or copper efflux, and several others mechanisms involved in metal processing.
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| Scientisist have analysed the genome of Ralstonia metallidurans for genes encoding homologues of established and putative transport proteins; 13% of all genes in Ralstonia metallidurans encode such homologues. Nearly one-third of the transporters identified (32%) appear to function in inorganic ion transport with three-quarters of these acting on cations. Transporters specific for amino acids outnumber sugar transporters nearly 3 : 1, and this fact plus the large number of uptake systems for organic acids indicates the heterotrophic preferences of these bacteria. Putative drug efflux pumps comprise 10% of the encoded transporters, but numerous efflux pumps for heavy metals, metabolites and macromolecules were also identified.
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| ==Cell structure and metabolism== | | ==Cell structure and metabolism== |
| | | Describe any interesting features and/or cell structures; how it gains energy; what important molecules it produces. |
| Ralstonia metallidurans uses a variety of substrates as its carbon source or it can grow chemo-lithotropically using molecular hydrogen as the energy source and carbon dioxide as a carbon source. When nitrate is present Ralsonia metallidurans can grow anaerobically.
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| Its optimal growth temperature is 30 çC.
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| ==Ecology== | | ==Ecology== |
| | | Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc. |
| Due to its ability to withstand high concentrations of heavy metals it renders it as a potential agent of bioremediation of soil and water contaminated with heavy metals or chlorinated organic compounds as well as an ideal model organism for understanding metal resistance phenotypes.
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| Lead contamination is a serious threat to human health and the environment. Lead levels are typically measured by using atomic absorption spectroscopy or other related instrumental methods. Developent of fluorescent Lead II Probe from Lead II-regulatory protein isolated from Ralstonia Metallidurans could provide rapid, on-site evaluation of the lead content of a sample.
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| ==Pathology== | | ==Pathology== |
| | | How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms. |
| Ralstonia metallidurans is not a pathogen and does not inhabit any host organisms.
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| ==Application to Biotechnology== | | ==Application to Biotechnology== |
| | | Does this organism produce any useful compounds or enzymes? What are they and how are they used? |
| Interestingly, enzymes from Ralstonia metallidurans were used by scientists in constructing a fuel cell. By encasing a pair of electrodes coated with these enzymes from Ralstonia metallidurans which oxidize hydrogen put inside a container filled with air and 3 percent more hydrogen. Trials of the fuel cell produced enough electricity to make a watch work. Larger scale productions are thought to be possible and are in the making.
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| [[[[Image:060802103513.jpg|thumb|300px|left|''Colored scanning electron image of bacterioform gold on a gold grain from the Hit or Miss Mine in northern Queensland''. [http://images.livescience.com/images/060718_gold_bacteria_01.jpg]]]
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| ==Current Research== | | ==Current Research== |
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| It is being researched that Ralstonia metallidurans could be involved in precipitating gold out of solution. It has an ability to survive in gold concentrations that would kill most other organisms.It is possible that the microbe screens out the gold as part of an effort to detoxify its immediate environment.
| | Enter summaries of the most recent research here--at least three required |
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| ==References== | | ==References== |
| | | [Sample reference] [http://ijs.sgmjournals.org/cgi/reprint/50/2/489 Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "''Palaeococcus ferrophilus'' gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". ''International Journal of Systematic and Evolutionary Microbiology''. 2000. Volume 50. p. 489-500.] |
| http://www.livescience.com/othernews/060718_gold_bacteria.html | |
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| http://www.physorg.com/news94144517.html
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| http://genamics.com/cgi-bin/genamics/genomes/genomesearch.cgi?field=Relevance&query=Bioremediatio...
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| http://www.iran-daily.com/1385/2615/html/science.htm
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| Edited by student of [mailto:ralarsen@ucsd.edu Rachel Larsen] and Kit Pogliano | | Edited by student of [mailto:ralarsen@ucsd.edu Rachel Larsen] and Kit Pogliano |
A Microbial Biorealm page on the genus Ralstonia metallidurans
Classification
Higher order taxa
Kingdom: Bacteria
Phylum: Proteobacteria
Class: Beta Proteobacteria
Order: Burkholderiales
Family: Ralstoniaceae
Genus: Ralstonia
Species: R. metallidurans
[Others may be used. Use NCBI link to find]
Species
Genus species
Description and significance
Describe the appearance, habitat, etc. of the organism, and why it is important enough to have its genome sequenced. Describe how and where it was isolated.
Include a picture or two (with sources) if you can find them.
Genome structure
Describe the size and content of the genome. How many chromosomes? Circular or linear? Other interesting features? What is known about its sequence?
Does it have any plasmids? Are they important to the organism's lifestyle?
Cell structure and metabolism
Describe any interesting features and/or cell structures; how it gains energy; what important molecules it produces.
Ecology
Describe any interactions with other organisms (included eukaryotes), contributions to the environment, effect on environment, etc.
Pathology
How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.
Application to Biotechnology
Does this organism produce any useful compounds or enzymes? What are they and how are they used?
Current Research
Enter summaries of the most recent research here--at least three required
References
[Sample reference] Takai, K., Sugai, A., Itoh, T., and Horikoshi, K. "Palaeococcus ferrophilus gen. nov., sp. nov., a barophilic, hyperthermophilic archaeon from a deep-sea hydrothermal vent chimney". International Journal of Systematic and Evolutionary Microbiology. 2000. Volume 50. p. 489-500.
Edited by student of Rachel Larsen and Kit Pogliano
