Bdellovibrio exovorus
Classification
Higher order taxa
Domain: Bacteria
Phylum: Proteobacteria
Class: Deltaproteobacteria
Order: Bdellovibrionales
Family: Bdellovibrionaceae
Species
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NCBI: Taxonomy [1] |
Bdellovibrio exovorus
Description and significance
a. Bdellovibrio exovorus is a parasitic, predatory bacterium whose name means “Leech-like vibrating outside-devourer” (Gr. Bdella, leech, sucker; L. vibrio, vibrating; Gr. exo-, outside, L. -vorus, to eat.) (2). B. exovorus was first isolated from sewage in London, Ontario, Canada, and sequenced in 2013 by the Weizmann Institute of Science (3).
b. B. exovorus are gram-negative, comma-shaped rods, about 0.5 um wide and 0.5-1.4 um long. They have a single, polar, sheathed flagellum that is 29 nm wide. These predatory bacteria have 2 phases in their life cycle: first, they swim freely to attack bacteria, and second they attach to the outside of their prey. Unlike their closest relative B. bacteriovorus, they do not burrow inside their prey cell, they have no periplasmic stage, and they do not form a bdelloplast. B. exovorus undergoes cell division via binary fission while attached to the prey cell. As it feeds, it leaves behind small plaques on the empty husks of their stalked prey cells. B. exovorus' most common prey cell is Caulobacter crescentus, and actually will not prey upon Escherichia coli (2).
Existing genus MicrobeWiki Link: https://microbewiki.kenyon.edu/index.php/Bdellovibrio
Genome and genetics
a. Bdellovibrio exovorus belongs to the major branch of prokaryotes called delta proteobacteria. The most closely related species is Bdellovibrio bacteriovorus . Based on 16S rRNA sequences, the most closely related genera include Desulfomonile, Desulfuromonas, and more distantly, Bacteriovorax.
b. Briefly describe any extra-chromosomal elements or genetic tools that are used to study the bacterium: viruses, plasmids, transposons that allow genetic manipulation and analysis. The CRISPR system has been used to count DNA scaffolds in the genome.
c. The sequence of Bdellovibrio exovorus was determined using whole genome sequencing (Weizmann Institute of Science, 2013), and can be found in its entirety on the Joint Genome Institute database. It has a total genome size of 2,657,893 bases, a %G+C content of 41.92%, and 2,656 genes. Of those genes, 2,619 (98.61%)are protein coding genes, 37 (1.39%) are RNA genes (of which 34 are for tRNA and 3 are for rRNA), and 1 (0.04%) is a pseudogene.
Nutrition and metabolism
a.Describe the growth characteristics of your bacterial species; sources of C, N, electrons; respires/ferments, uses O2, etc.
b.What kinds of culture conditions (temp, pH, media) are needed for laboratory study?
c.What kinds of waste, by-products, volatile compounds are generated?
Ecology / Pathology
Ecology: How is your microorganism important in the ecosystem where it is found? How does it impact other organisms in the environment (could be positive or negative impact)?
Pathology: How does the microbe cause disease as it interacts with the host? Describe any specific toxins or pathways that are used for invading and causing disease in the host. What treatment is used to inhibit or kill the microbe?
Current Research
Describe recent research and findings that have been done with this organism. The research can be clinical, applied or basic research. This section should be based on 2 recent papers (10 years or less) and summarized in your own words.
References
[2] Koval SF, Hynes SH, Flannagan RS, Pasternak Z, Davidov Y, Jurkevitch E. Bdellovibrio exovorus sp. nov., a novel predator of Caulobacter crescentus. Int. J. Syst. Evol. Microbiol [Internet]. 2013 [cited 13 Feb 2017];(63):146–151.
[3] Bdellovibrio exovorus JSS [internet]. University of California- Integrated Microbial Genomes & Microbial Samples. [cited 2017 Feb 13] Availible from https://img.jgi.doe.gov/cgi-bin/m/main.cgi?section=TaxonDetail&page=taxonDetail&taxon_oid=2541047022
[4] Brenner DJ. 2005. Bergey's manual of systematic bacteriology. Vol. 2. The proteobacteria. Part C. The alpha-, beta-, delta-, and epsilonproteobacteria. Staley JT, editor. New York (NY): Springer. p.1040-1053.
Authored by Kip Pierce, a student of CJ Funk at John Brown University
