Also known as “the world’s smallest hunter”, this Gram-negative curved rod-shaped bacterium preys upon other Gram-negative bacteria. What it lacks in stature, only .2-.5 nm by .5-1.4 µm, it makes up in speed. It moves via a single unsheathed polar flagellum at an incredible rate of 100 cell lengths per second. When taken this into consideration it would be like a 6 foot tall human running at a speed of over 400 mph. This bacterium can be found in many diverse environments from fresh water, to marine conditions, to even sewage and soil samples. While the wild type strains can be found in optimal growth of 28-30°C, certain marine strains have been found to grow in temperatures around 6°C. Bdellovibrio has a biphasic life cycle in which one is characterized by its non-growing, non-motile intracellular reproduction and the other by its predatory and motile involvement. The later phase is directed not by the presence of its prey but rather by the favored ionic conditions of its victims. Its prey is of the Gram-negative type because when entering the host cell it penetrates both the outer membrane and the peptidoglycan layer, where it resides in the periplasmic space, characteristic of only Gram-negative species. The host cell is then transformed into a spherical bdelloplast, giving the bacterium a nutrient rich environment to reproduce and grow.
Resources:
- Website of Arizona State Life Sciences Department http://lsvl.la.asu.edu/mic494/old/html/bdellovibrio.html
- “Bdellovibrio genome sequenced” by David Secko http://www.biomedcentral.com/news/20040130/02/
- “Bacteria Beware: The Life and Times of Bdellovibrio” by Laurel Crosby
http://commtechlab.msu.edu/sites/dlc-me/curious/caOc96LC.html*Disclaimer - This report was written by a student participaring in a microbiology course at the Missouri University of Science and Technology. The accuracy of the contents of this report is not guaranteed and it is recommended that you seek additional sources of information to verify the contents.
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