Myxococcus xanthus

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Myxococcus xanthus
Scientific classification
Phylum: Proteobacteria Genus: Myxococcus Species: M. xanthus
Binomial name
Myxococcus xanthus

Description and significance

Myxococcus xanthus is a social organism, which are self-organized, saprotrophic and predatory. M. xanthus is a rod shaped, gram negative bacteria, which uses a form of gliding for locomotion. There's been recent discovery of two types of systems used for locomotion. The first system is type IV pilli, which is used as a type of hook. The second system is mucus secreting, which tend to form sites of focal adhesion. During starvation periods this bacteria has been discovered to use a form of chemotaxis signaling in order to produce and regulate multi-cellular rippling during predation. Predation takes place a multi-cellular synchronizing mechanism. The ability for this bacteria to communicate with others and be able to work together towards the targeted prey, makes it a good candidate for research. M. xanthus tends to form fruiting bodies. Within these fruiting bodies there are spores. These spores will germinate in order to return to a vegetative cycle as soon as conditions are favorable. M.xanthus is a predator to other bacteria, but harmless to humans.

Genome structure

M.xanthus is one of the largest prokaryotic genomes to be sequenced. Length of genome is 9,139,763 nt. Number of genes: 7456, Protein coding genes: 7331, Structural RNAs: 79, Pseudo genes:43, Topology: circular.

Cell structure and metabolism

M. xanthus has a life cycle which includes; predation, fruit bodies and swarming. Fruit bodies usually form from the cause of starvation, these bodies can then form into stress-resistant spores. Leucine is an important amino acid for the growth of this bacteria.

Ecology

M. xanthus is commonly found in high organic matter soil with preference to a range of pH from 5-8. This bacteria lives in a multi-cellular unit.

Pathology

This bacteria is a predator of other bacteria, but non pathogenic. The fact that M. xanthus moves by chemotaxis and usually moves towards a prey resulted in the word "predataxis". M. xanthus is not a single unit when attacking a prey, rather there is a sense of cooperation. Predation of M. xanthus includes release of toxic and lytic substances. These substances can degrade or paralyze the targeted prey. Predation takes place by many cell to cell signaling happening, these signals are named A, B, C signals which are also used in the transformation of the life cycle.

Application to biotechnology

The unique feature of M.xanthus being predatory towards other bacteria, is of great use for studies. This feature has been hypothesis to be utilized in order to predate for other harmful bacteria. Many of the secondary metabolites secreted by M. xanthus are utilized to lyse other soil microbes. One of the many purposes these secondary metabolites serves is the ability to target pathogenic fungi in plants.

Current research

"Identification of Additional Players in the Alternative Biosynthesis Pathway to Isovaleryl-CoA in the Myxobacterium Myxococcus xanthus Helge B. Bode,[a] Michael W. Ring,[a] Gertrud Schwr, Matthias O. Altmeyer, Carsten Kegler, Ivy R. Jose, Mitchell Singer, and Rolf Miller (2009)”

In this research, there has been found an alternative pathway to Isovaleryl - CoA in M. xanthus. The alternative pathway that has been discovered is 3-hydroxy-3-methylglutaryl-CoA synthase (MvaS), which is persuaded in mutants with non functional leucine degradation or during the formation of fruiting bodies.

"Genetic circuitry controlling motility behaviors of Myxococcus xanthus, Ta, m Mignot1 and John R. Kirby2 (2008)"

Current locomotion studies have revealed that the synchronizing of both motor systems is due to spatial oscillation of motility proteins. M. xanthus predation tactics are being studied with results such as: a sort of cell reversal motion which cause a wave like effect, directing towards the prey.

"Site-specific receptor methylation of FrzCD in Myxococcus xanthus is controlled by a tetra-trico peptide repeat (TPR) containing regulatory domain of the FrzF methyltransferase, Ansley E. Scott, Eric Simon, Samuel K. Park, Philip Andrews2 and David R. Zusman1 (2008)"

There is also a correlation between the ripple wavelength and amount of prey available. High amounts prey there are shorter wavelengths, lower amounts of prey cause a longer wavelength. Current research has positive results on the identification of the pathway responsible for chemotaxis in this bacteria. The assumed pathway is Frz, which activates FrCD, a chemotaxis protein.

References

<http://en.wikipedia.org/wiki/Myxococcus_xanthus>

<http://microbewiki.kenyon.edu/index.php/Mycoccus_xanthus>

<Genetic circuitry controlling motility behaviors of Myxococcus xanthus, Taˆ m Mignot1* and John R. Kirby2 >

<The social lifestyle of myxobacteria, Arthur L. Koch* and David White >

<http://www.medicine.uiowa.edu/CCOM/news/video-predataxis/>

<http://www.nytimes.com/2008/11/04/science/04obswarm.html?_r=1>

<Site-specific receptor methylation of FrzCD in Myxococcus xanthus is controlled by a tetra-trico peptide repeat (TPR) containing regulatory domain of the FrzF methyltransferase, Ansley E. Scott, Eric Simon, Samuel K. Park, Philip Andrews2 and David R. Zusman1*>

<http://www.ncbi.nlm.nih.gov/sites/entrez?Db=genome&Cmd=ShowDetailView&TermToSearch=250>

<http://www.bio.indiana.edu/facultyresearch/faculty/Velicer.html>