Epulopiscium fishelsoni: Difference between revisions

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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.
Describe any interesting features and/or cell structures; how it gains energy; what important molecules it produces.
''E. fishelsoni'' has a layer of flagella around its surface. When viewed in a light microscope video it is shown swimming and has a vibrating layer during liquid movement which is the layer of flagella propelling the cell. Beneath the outer surface is a peripheral layer of rolled up membranes, followed by a dense region with large, lightly stained inclusions. In the central region of the cell there is often a membrane-bound, dark-staining area. This region has been previously referred to as a daughter cell and is involved in the reproductive process. Upon completion of development, the daughter cells emerge through a centrally located, oblong split in the envelope of the mother cell. Epulos possess bacterial-type flagella rather than eukaryote-type cilia. The epulo flagella have a diameter of 14 to 18 nm in thin section and in freeze fracture profile, compared with 200 to 250 nm for eukaryote cilia. It has not been possible to negatively stain the flagella of very large epulo specimens.


==Ecology==
==Ecology==

Revision as of 18:32, 29 August 2007

A Microbial Biorealm page on the genus Epulopiscium fishelsoni

Light micrograph of a large epulo and a ciliated eukaryote (C). Copyright © 1991, American Society for Microbiology

Classification

Higher order taxa

Kingdom: Bacteria

Phylum: Firmicutes

Class: Clostridia

Order: Clostridiales

Genus: Epulopiscium

Species

NCBI: Taxonomy

Epulopiscium fishelsoni

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.

Epulopiscium was first discovered in 1985 by Lev Fishelson. He found them inside the intestines of a brown surgeonfish and was initially classified as a protist because of its large size. Epulopiscium fishelsoni was later discovered by Linn Montgomery and in 1993 Norman Pace performed an rRNA analysis which confirmed that it was actually a bacteria. At the time E. fishelsoni was the largest known bacteria, ranging from a length of ~30 to >600μm and a volume of >2,000-fold [2]. E. fishelsoni is a gram-positive bacterium that has an explicit symbiotic relationship with its surgeonfish hosts.

Transmission electron micrographs of compact nucleoids of E. fishelsoni. Copyright © 1998, American Society for Microbiology

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.

E. fishelsoni has a layer of flagella around its surface. When viewed in a light microscope video it is shown swimming and has a vibrating layer during liquid movement which is the layer of flagella propelling the cell. Beneath the outer surface is a peripheral layer of rolled up membranes, followed by a dense region with large, lightly stained inclusions. In the central region of the cell there is often a membrane-bound, dark-staining area. This region has been previously referred to as a daughter cell and is involved in the reproductive process. Upon completion of development, the daughter cells emerge through a centrally located, oblong split in the envelope of the mother cell. Epulos possess bacterial-type flagella rather than eukaryote-type cilia. The epulo flagella have a diameter of 14 to 18 nm in thin section and in freeze fracture profile, compared with 200 to 250 nm for eukaryote cilia. It has not been possible to negatively stain the flagella of very large epulo specimens.

Ecology

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

Pathology

E. fishelsoni is not known to cause any disease or be harmful to anything. It has a symbiotic relationship with surgeonfish which seems to be mutually beneficial. In fact, E. fishelsoni can not be cultured outside of its host and can only be found in the gut of that family of fish.

Application to Biotechnology

E. fishelsoni does not produce any useful compound or enzymes that can be used for biotechnology. All that is known is that this bacteria helps regulate the pH in the gut of its host. This regulation is cycled throughout the day and is controlled based on the surgeonfish's activity.

Current Research

There are currently no ongoing nor recent research being done about E. fishelsoni. After its discovery in 1985, thorough examinations of its structure and research about its reproduction process in the 90's, there is not much left that we don't know about this bacteria. There aren't any signs nor indications of future research projects for E. fishelsoni.

References

1. Clements, K. D. and Bullivant, S. "An Unusual Symbiont from the Gut of Surgeonfishes May Be the Largest Known Prokaryote". Journal of Bacteriology. Sept. 1991. Volume 173, No. 17. p. 5359-5362.

2. Bresler, V., Montgomery, W.L., Fishelson, L., and Pollak, P.E. "Gigantism in a Bacterium, Epulopiscium fishelsoni, Correlates with Complex Patterns in Arrangement, Quantity, and Segregation of DNA". J Bacteriol. 1998 November; 180(21): 5601–5611.

3. Flint, J.F., Drzymalski D., Montgomery, W.L., Southam, G., and Angert, E.R. "Nocturnal Production of Endospores in Natural Populations of Epulopiscium-Like Surgeonfish Symbionts". J Bacteriol. 2005 November; 187(21): 7460–7470.


Edited by student of Rachel Larsen