Metrics details Abstract Bdellovibrio bacteriovorus, gen. These unusual bacteria cause reactions that are similar in their outward manifestations to bacteriophage-induced lysis. Upon plating a mixture of host bacteria and parasites, confluent lysis or single plaque formation occurs, just as in titration experiments with bacteriophage. However, the parasite plaques develop more slowly than phage plaques. Lysis of host bacteria in liquid culture is accompanied by a decrease in optical density; actually, a population of infected host bacteria is replaced by a population of the tiny parasite.
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Bdellovibrio bacteriovorus: HD, J Description and significance Bdellovibrios were discovered by Stolp and Petzhold in , 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.
The complete genome consists of a single circular chromosome that is 3,, nucleotides long. These enzymes are necessary for B. Some of these enzymes need to be secreted out of B. Therefore, the genome of B. In fact, B.
These gene clusters are essential for the motility B. However, the organism sheds its flagellum once it makes irreversible contact with its prey cell suggesting that the flagellum is not required for it to grow. In the free-living or mobile phase, B. During the mobile phase, most of the metabolic activity is involved in motility and prey detection.
A large variety of metabolic activities occur during this phase. After entry into the prey cell, B. One of these areas is that B. The reason for this is that B. It can break down or rearrange these precursors for the biosynthesis of homologous polymers.
The uptake of nucleoside monophosphates and glycerol phoshphates greatly reduces the amount of energy that B. There has also been evidence that B. Experiments have shown that the energy efficiency of B. They have been found in soil samples, rhizosphere of plant roots, rivers, oceans, sewage, intestines and feces of birds and mammals, and even in oyster shells and the gills of crabs. Its optimal temperature is between C, making B.
It can live in a range of salinity and is resistant to pollution of its environment. This makes B. It seems that the rich environment of biofilms supply B. Research has shown that B. Coli biofilm that is grown on stainless steel. It is a known pathogen to Gram-negative bacteria, making it a possible biocontrol agent to many human pathogens.
Agriculturally, B. The use of B. Many experiments are performed to test how it specifically recognizes its prey. There is also research on how B. It is also highly possible that a slight change in its genetic code can allow B. Prey Selection of B.
This research showed that B.
Bdellovibrio bacteriovorus[ edit ] The most well studied of these is Bdellovibrio bacteriovorus, which is found almost exclusively in host dependent growth in nature. The Bdellovibrio bacterium then forms a structure called a bdelloplast. This bdelloplast is created as the host cell is modified to become spherical in shape. Inside the bdelloplast, the singular large flagellum of the predatory Bdellovibrio is lost. The host cell is then rapidly killed allowing the passage of molecules from the interior of the host cytoplasm through to the periplasm freely, and the periplasm dwelling Bdellovibrio to feed.
Harini Department of Periodontics, A. Harini, Department of Periodontics, A. E-mail: moc. This article has been cited by other articles in PMC. Many authors have unfolded the possible use of BALOs as biological control agents in environmental as well as medical microbiological settings.