Vibrio harveyi
Vibrio harveyi Credit: Photo courtesy of Bonnie Bassler lab
Habitat
Bioluminescent bacteria are bacteria that “glow in the dark,” just as the commonly known firefly. Based on their 16S ribosomal RNA (rRNA) classification, they belong to the group of bacteria known as Proteobacteria, which is further sub-divided into five groups, including the gamma proteobacteria. This group includes many families, one of which is the Vibrionaceae (bioluminescent bacteria). One of the Vibrios is human pathogen and causes cholera. Vibrio harveyi can be found found globally in marine environments, either in a free-living state or in symbiosis with marine life.
Biology
The cells of the Vibrionaceae are gram-negative, non-sporulating rods, usually 0.5 microns by 2 microns, and they have locomotor organelles called flagella. Vibrios have a group of flagella at one end if the cell (polar flagella) and the flagella are encased in a sheath that is a continuation of the outer membrane of the bacterial cell wall. In contrast, the Photobacterium genus only has unsheathed flagella. The ability to produce light is dependent upon the concentration of the organisms in the substrate (i.e., sea water or special growth medium in the laboratory). The light generating reactions require oxygen, and the final product of luminescence reactions is excited luciferase, a chemical, which can generate light. Bioluminescent bacteria produce a specific chemical called an autoinducer (sometimes more than one), which can induce bioluminescence reactions in bacterial cells when they are in high concentrations. At lower concentrations, specifically when dispersed in the ocean, the cells do not produce light. However, some marine animals, such as octopi and shrimp can harbor large numbers of these organisms in particular organs, and those organs will luminesce. Other chemical compounds similar to autoinducer have been isolated from other bacteria species, such as E. coli and Salmonella, among others, which do not produce light. In this case their role is informational. On the basis of the concentration of these compounds, the non-bioluminescent bacterial cell "knows" how many other cells are nearby, and this determines whether they act as individuals (few other organisms near) or as a group (many other organisms near).
Sequencing Plan
The genome of Vibrio harveyi has been sequenced to 8X coverage using a combination of plasmid and fosmid end sequences. The genome has undergone automated sequence improvement (pre-finishing) followed by manual finishing, and automated annotation. The National Science Foundation (NSF) provided funding for the complete sequence of the Vibrio harveyi genome.
The finished genome sequence is now complete and submitted to GenBank. It consisted of two chromosomes and a plasmid. The sequences are accessible using the following accession numbers:
Contacts
| Name | Affiliation |
|---|---|
| Patrick Minx | The Genome Institute, Washington University School of Medicine |
| Bonnie Bassler | Howard Hughes Medical Institute, Princeton University |
Sequences & Maps
Assemblies
| Name | Date | Description | Blast DBs |
| Vibrio_harveyi-3.0 | Jan 05, 2006 | production reads only | contigs supercontigs |
| Vibrio_harveyi-4.0 | Mar 05, 2006 | 8.2X | contigs supercontigs |
| Vibrio_harveyi-5.0 | Jul 10, 2006 | 10.8X | contigs supercontigs |
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