Difference between revisions of "Roseobacter denitrificans"

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==Description and significance==
 
==Description and significance==
Roseobacter denitrificans is a purple aerobic anyoxygenic phototrophic (AAP) bacterium that dwells free-living in lakes and ocean surface waters, soils and even near deep sea hydrothermal vents.  It was isolated from coastal marine sediments in Australia.
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Roseobacter denitrificans is a purple aerobic anyoxygenic phototrophic (AAP) bacterium that dwells free-living in lakes and ocean surface waters, soils and even near deep sea hydrothermal vents.  It was isolated from the surfaces of green seaweeds of the coastal marine sediments in Australia.  Members of the Roseobacter clade are widespread and abundant in such marine environments, having diverse metabolisms.  The purple proteobacteria in particular, are the only known organisms to capture light energy to enhance growth  requiring the presence of oxygen yet do not produce oxygen themselves. The highly adaptive AAPs compose more than 10% of the microbial community in some euphotic upper ocean waters and are potentially major contributors to the fixation of the greenhouse gas CO2.
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The marine AAP species Roseobacter denitrificans grows not only photoheterotrophically in the presence of oxygen and light but also anaerobically in the dark using nitrate or trimethylamine N-oxide as an electron acceptor.  It is the most studied AAP for this reason and is one of the main model organisms to study aerobic phototrophic bacteria.
  
It was isolated in  
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Its importance in its genome sequenced are for the following reasons: 1) the work on respiratory and photosynthetic electron transfer pathways in this organism establishes this species as the model aerobic phototrophic bacterium (Candela et al. 2001; Okamura et al. 1986; Schwarze et al. 2000) ; 2) it is the only aerobic phototrophic bacterium that is capable of anaerobic growth, by use of nitrate as a terminal electron acceptor (Yurkov and Beatty 1998) , which will facilitate subsequent studies of the effects of oxygen on photosynthetic and other metabolic processes; 3) it is a marine bacterium, and so may be representative of the globally huge population of aerobic phototrophic bacteria enumerated in oceanic samples (Kolber et al. 2001)
  
 
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.
 
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.

Revision as of 06:00, 28 August 2007

A Microbial Biorealm page on the genus Roseobacter denitrificans

Classification

Higher order taxa

Bacteria, Proteobacteria, Alphaproteobacteria, Rhodobacterales, Rhodobacteraceae, Roseobacter

Species

Roseobacter denitrificans sp. OCh114 (previously called Erythrobacter sp. OCh114)

NCBI: Taxonomy Genome

Description and significance

Roseobacter denitrificans is a purple aerobic anyoxygenic phototrophic (AAP) bacterium that dwells free-living in lakes and ocean surface waters, soils and even near deep sea hydrothermal vents. It was isolated from the surfaces of green seaweeds of the coastal marine sediments in Australia. Members of the Roseobacter clade are widespread and abundant in such marine environments, having diverse metabolisms. The purple proteobacteria in particular, are the only known organisms to capture light energy to enhance growth requiring the presence of oxygen yet do not produce oxygen themselves. The highly adaptive AAPs compose more than 10% of the microbial community in some euphotic upper ocean waters and are potentially major contributors to the fixation of the greenhouse gas CO2. The marine AAP species Roseobacter denitrificans grows not only photoheterotrophically in the presence of oxygen and light but also anaerobically in the dark using nitrate or trimethylamine N-oxide as an electron acceptor. It is the most studied AAP for this reason and is one of the main model organisms to study aerobic phototrophic bacteria.

Its importance in its genome sequenced are for the following reasons: 1) the work on respiratory and photosynthetic electron transfer pathways in this organism establishes this species as the model aerobic phototrophic bacterium (Candela et al. 2001; Okamura et al. 1986; Schwarze et al. 2000) ; 2) it is the only aerobic phototrophic bacterium that is capable of anaerobic growth, by use of nitrate as a terminal electron acceptor (Yurkov and Beatty 1998) , which will facilitate subsequent studies of the effects of oxygen on photosynthetic and other metabolic processes; 3) it is a marine bacterium, and so may be representative of the globally huge population of aerobic phototrophic bacteria enumerated in oceanic samples (Kolber et al. 2001)

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]

1) (Fleischman and Kramer 1998; Yurkov and Beatty 1998; Yurkova et al. 2002)

2) Swingley W.D., Sadekar S., Mastrian S.D., Matthies H.J., Hao J., Ramos H., Acharya C.R., Conrad A.L., Taylor H.L., Dejesa L.C., Shah M.K., O'Huallachain M.E., Lince M.T., Blankenship R.E., Beatty J.T., Touchman J.W. ; "The complete genome sequence of Roseobacter denitrificans reveals a mixotrophic rather than photosynthetic metabolism"; J. Bacteriol. 189:683-690 (2007)

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.roseobase.org/roseo/och114.html

http://genomes.tgen.org/rhodobacter.html


Edited by student of Rachel Larsen