Vibrio harveyi

Description and Significance

Vibrio harveyi is a facultative anaerobic, gram negative bacteria found in marine environments (mainly in tropical locations). This bacteria may be either free-living or in symbiosis with marine life like their close relations, Vibrio fischeri. V. harveyi’s 16s RNA classifies them in the Proteobacteria phylum, and their bioluminescence places them in the Vibrionaceae family.^1,8 Non-sporulating rods (0.5 microns x 2 microns) help to maintain their structure, while polar flagella whose sheath is an extension of their outer membrane help the bacteria to move. V. harveyi produces an enzyme (luciferase) that generates light seen in their characteristic bioluminescent capabilities, whose functioning is dependent on the cell concentration, and works via quorum sensing. The use of quorum sensing and bioluminescence by V. harveyi is closely studied because of its aid in understanding how bacteria communicate with its environment, detect multiple environmental cues, and use this information as a means of regulating gene expression.² Furthermore, V. harveyi causes some diseases which affect agriculture and cause economic losses; understanding their functioning may help to alleviate these problems as well.⁶ Also, the potential for the development of anti-microbial drugs can be investigated with V. harveyi.³

Genome Structure

The Vibrio harveyi genome has been sequenced up to 8x magnification. Through sequencing it has been determined that the Vivrio harveyi genome consists of two chromosomes and one plasmid. Chromosome I contains 3,765,351 nucleotides; chromosome II contains 2,204,018 nucleotides; the plasmid contains 89,008 nucleotides.² Chromosomes I, II, and the plasmid are circular, and the entire genome contains 6040 genes encoding proteins and 166 genes encoding RNA.⁸

References

[1] Classification. (2007). Vibrio harveyi. Retrieved April 10, 2009, from Microbe Wiki Web site:

    http://microbewiki.kenyon.edu/index.php/Vibrio_harveyi

[2] Background. (n.d.). Vibrio harveyi. Retrieved April 10, 2009, from Washington University in St. Louis School of Medicine Genome Sequencing Center Web site: http://genome.wustl.edu/genome.cgl?GENOME=Vibrio%20harveyi

[3] Bassler, B. (n.d.). Cell-to-cell communication in bacteria. Retrieved April 10, 2009, from Department of Molecular Biology Princeton University Web site:http://www.molbio.princeton.edu/index.php?option=content&task=view&id=27

[4] Khemayan, K., Pasharawipas, T., Puiprom, O., Sriurairatana, S., Suthienkul, O., & Flegel, T. W. (2006, February). Unstable lysogeny and pseudolysogeny in vibrio harveyi siphovirus-like phage 1. Applied Environmental Microbiology, 72(2), 1355-1363. Retrieved April 10, 2009. doi:10.1128/AEM.72.2.1355-1363.2006

[5] Pompeanl, A. J., Irgon, J. J., Berger, M. F., Bulyk, M. L., Wingreen, N. S., & Bassler, B. L. (2008, August 15). The vibrio harveyi master quorum-sensing regulator, luxR, a tetR-type protein is both an activator and repressor: DNA recognition and binding specificity at target promoters. Molecular Microbiology, 70(1), 76-88. Retrieved April 10, 2009. doi:10.1111/ j.1365-2958.2008.06389.x

[6] Rao, A. V. (2008, September 12). Vibriosis in shrimp aquaculture. Retrieved April 10, 2009, from http://www.engormix/e_articles_view.asp?art=1179&AREA=ACU-165

[7] Lenz, D. H., Mok, K. C., Lilley, B. N., Kulkarni, R. V., Wingreen, N. S., & Bassler, B. L. (2004,July 9). The small rna chaperone hfq and multiple small rnas control quorum sensing in vibrio harveyi and vibrio cholerae. Cell, 118(1), 69-82. Abstract retrieved April 13, 2009, from Laboratory of Molecule Biology, National Cancer Institute Web site: http://lib.bioinfo.pl/pmld:15242645

[8] Vibrio harveyi genome [Data file]. (n.d.). Retrieved April 18, 2009, from Kegg Web site:

    http://www.genome.jp/kegg-bin/show_organism?org=vha