Bdellovibrio bacteriovorus

From MicrobeWiki, the student-edited microbiology resource

A Microbial Biorealm page on the genus Bdellovibrio bacteriovorus


Higher order taxa

Bacteria; Proteobacteria; Deltaproteobacteria; Bdellovibrionales; Bdellovibrionaceae; Bdellovibrio


Bdellovibro bacteriovous

NCBI: TaxonomyGenome


Bdellovibrio bacteriovorus HD100

Description and significance

Bdellovibrios were discovered by Stolp and Petzhold in 1962, in an attempt to isolate bacteriophage from soil samples. Stolp and Petzhold observed unique plaques in their samples that took several days to develop and continued to grow for over a week, instead of plaques caused by bacteriophages that would appear within hours. A closer inspection of the plaques under a light microscope revealed cells that were small, highly motile, and vibrio-shaped. These cells were Bdellovibrios.

After the discovery of Bdellovibrios further observations revealed many interesting and unique properties. One property that makes Bdellovibrios interesting is that it is a parasite to other gram negative bacterias. Bdellovibrios have biphasic life-cycles that include an attack phase, and a free living and mobile phase.(2) The attack phase is when it attaches to another gram negative bacteria and imbeds itself into its periplasm, it then procedes to grow and replicate itself by degrading the host bacterium from the inside out.(1) In the free living and mobile phase, Bdellovibrios move about in search of host or prey bacteria so it can intiate attack phase again.(2) Each of these phases are of interest to researchers because it reveals unique cell-cell interactions and unusual cell metabolism.(1)

Bdellovibrio bacteriovorus is a small, curved, and highly motile gram negative bacteria approximately 0.2 to 0.5μm wide and 0.5 to 2.5μm long.(3) It has been found in many environments that include soil, sewage, and other terrestial and aquatic habitats. B. bacteriovorus has been observed to only attack gram negative bacteria which includes many plant, animal and human pathogens making it an execellent candidate as a biocontrol agent.(2) The study of its degradative enzymes and host targeting system has shed some insight in possible designs for new antimicrobial agents.(3)

Genome structure

The sequencing of the B. bacteriovorus HD100 genome was completed on 01/31/2004. The complete genome consists of a single circular chromosome that is 3,782,950 nucleotides long. The entire genome has a 50% GC content and contains 3629 genes which codes for 3587 proteins and 42 structural RNAs.(4)

Of the large number of proteins that the B. bacteriovorus genome encodes, many of them are degradative and lytic enzymes(2). These enzymes are necessary for B. bacteriovorus to breakdown its host or prey cell. Some of these enzymes needs to be secreted out of B. bacteriovorus and into its host cell, while degradative products needs to be transported into the B. bacteriovorus. Therefore, the genome of B. bacteriovorus also includes a large amount of transport proteins. In fact, B. bacteriovorus has the potential protein secretory capabilities of at least five types of outer membrane secretion systems and four types of inner membrane secretion systems.(5)

Cell structure and metabolism



Application to Biotechnology

Current Research


(1)Bdellovibrio Host Dependence: the Search for Signal Molecules and Genes That Regulate the Intraperiplasmic Growth Cycle. By Michael F. Thomashow and Todd W. Cotter




Edited by student of Rachel Larsen and Hiu Cheng