Vibrio harveyi

A Microbial Biorealm page on the genus Vibrio harveyi

Classification

Higher Order Taxa

Kingdom: Bacteria

Phylum: Proteobacteria

Class: Gammaproteobacteria

Order: Vibrionales

Family: Vibrionaceae

Species

Vibrio harveyi

Synonyms: Lucibacterium harveyi, Beneckea harveyi, Achromobacter harveyi, Pseudomonas harveyi, Photobacterium harveyi, (Johnson and Shunk, 1936); Vibrio carchariae (Grimes, 1985); Vibrio trachuri, (Iwamoto, 1996)

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.

Appearance: V. harveyi is curved rod shaped, Gram-negative, non-sporulating, and monotrichous (mobilized by a single polar flagellum). It also has the characteristic of bioluminesence.

Habitat: V. harveyi is found mainly in tropical marine environments including brackish water. V. harveyi is also found in symbiotic relationships with many marine organisms such as.....

Discovery: Johnson and Shunk 1936

Significance: Inter- and intra-bacterial communication, quorum sensing (Bassler). Sequencing of the genome would undoubtedly contribute to further understanding of this unique skill.

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?

The Microbial Sequencing Center of the Institute for Genomic Research is currently doing shotgun seguence research for the HY01 strain of Vibrio harveyi. This research is in conjunction with a project to identify the genome sequence for 17 different Vibrio species enabling extensive comprehension of the Vibrio genus.

Cell structure and metabolism

Describe any interesting features and/or cell structures; how it gains energy; what important molecules it produces.

Structure: Because V. harveyi is Gram-negative it has a cell wall that consists of two membranes: an outer membrane full of lipopolysaccharides and an inner cytoplasmic membrane. In between these is a periplasmic space housing a peptidoglycan layer.

Metabolism: Vibrio harveyi is a heterotrophic, facultative anaerobic bacterium meaning it can swap between aerobic respiration and fermentation. This characteristic helps V. harveyi survive in low oxygen concentrations when enough fermentable material is present. Bioluminecence is controlled by the regulatory gene luxR in V. harveyi as well as population density-sensing (quorum sensing) autoinducer signaling molecules. Expression occurs when the enzyme luciferace oxidizes an organic compound releasing free energy in the form of light!

Quorum-Sensing:

Ecology

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

Milky Sea: When large areas of open ocean water are filled with "V. harveyi living in association with colonies of the microalga Phaeocystis." For centuries mariners documented this strange instense glow coming from the ocean at night. Even Jules Verne wrote about it in Twenty Thousand Leagues Under the Sea, describing the effect as "myriads of infusoria." The most famous and most referenced photograph of the milky sea effect was done at the Monterey Bay Aquarium Research Institute. Researcher Steve Haddock stated, "...that the light produced by the bacteria is actually blue, not white." Going on to say that the effect appears white because "the rods in our eye (used for night vision) don't discriminate color." [1]

Pathology

How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.

V. harveyi is a known cause of luminous vibrosis in comercially farmed marine invertebrates Going out with a glow. (as opposed to a bang)

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

• Jennifer M. Henke and Bonnie L. Bassler. Three Parallel Quorum-Sensing Systems Regulate Gene Expression in Vibrio harveyi. J. Bacteriol. 2004 186: 6902-6914.

• Miller, Melissa B. and Bonnie L. Bassler. Quorum sensing in bacteria. Annual Review of Microbiology. 2001. 55:165-199

• Miller, S.D., S.H.D. Haddock, C.D. Elvidge, T.F. Lee. Detection of a bioluminescent milky sea from space. Proc. National Acadamy Science 2005. 102:14181-14184

• Nealson, K.H. and J.W. Hastings. Quorum sensing on a global scale: massive numbers of bioluminescent bacteria make milky seas Applied and Environmental Microbiology. 2006. 72:2295-2297

• Showalter, R.E., Martin, M.O., and Silverman, M.R. Cloning and nucleotide sequence of luxR, a regulatory gene controlling bioluminescence in Vibrio harveyi. J. Bacteriol. 1990. 172: 2946–2954.

Edited by Ryan Kendall of Rachel Larsen and Kit Pogliano's Bacteriology class Spring 2007