Vibrio fischeri NEU2011

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A page on the microorganism Vibrio fischeri

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This micrograph shows fluorescently stained Vibrio fischeri cells. Image taken by V. Brown, provided courtesy of the Vibrio fischeri Project.

Classification

Higher order taxa

Vibrio fischeri

  • Kingdom: Bacteria
  • Phylum: Proteobacteria
  • Class: Gamma Proteobacteria
  • Order: Vibrionales
  • Family: Vibrionaceae
  • Genus: Vibrio
  • Species: V. fischeri


Description and Significance

The Hawaiian bobtailed squid, Euprymna scolopes. This organism is the host for Vibrio fischeri cells. The squid and V. fischeri cells share a unique, symbiotic relationship. This image is courtesy of M. J. McFall-Njai and E. G. Ruby. University of Hawii, National Science Foundation.

Vibrio Fischeri is a member of the phylum proteobacteria. These bacteria are motile, gram-negative rods that are found in temperate and subtropical waters. These heterotrophic bacteria use flagella as a means of movement and they are most famous for their bioluminescence properties. V. Fischeri is mainly found living in symbiosis with various deep sea marine animals such as monocentrid fishes and bobtail squid. V. Fischeri is found within unique light-organs or as part of the normal gut of these marine animals (V. Fischeri).

V. Fischeri can also be found living as free bacteria in small quantities surviving on decaying organic matter. V. Fischeri use proteins coded by a set of genes called the lux operon to produce bioluminescence. The light is produced in a chemical reaction where luciferin is oxidized by the enzyme luciferase. As a result of the oxidation, a blue-green light is emitted. The symbiotic relationship between a strain of the V. Fischeri and its host, the bobtail squid Euprymna scolopes, has been studied extensively. The bobtail squid acquires these bacteria from its surroundings and uses it as a protection from predators. Within several hours of being ingested, these bacteria begin to change. They decrease in size, lose their flagella, and begin to emit light. These bacteria help to eliminate the squid’s shadow caused by the moonlight above (Vibrio Fischeri). The isolation and cloning of the lux gene from V. Fischeri, and their use as a reporter gene, have provided scientists with many valuable research techniques. The lux gene has enabled scientists to visually study and examine many living organisms at a cellular level. Likewise, V. Fischeri cells have been made commercially available to ecotoxicologists to detect contaminants in the environment more quickly and cheaper than most other available methods (Madigan M).

Genome Structure

The genome of V.fisheri contains 4273718 nucleotides, 3817 protein genes and 165 RNA genes. The chromosomes I and II are circular. The sequence of the chromosome 1 is NC_006840 and its lenght is equal to 2897536. The sequence of the chromosome II is NC_006842 and its lenght is equal to 1330333. The ES114 strain is characterized by a circular plasmid known as pES100. The number of taxonomy of the Vibrio fisheri is 312309 (KEGG).

References

  • Madigan M, Martinko J (editors) (2005). Brock Biology of Microorganisms (13th ed.). Prentice Hall.