Myxococcus xanthus is a fascinating bacteria discovered in 1892 by Roland Thaxter. M. xanthus thrives in soil at a pH between 5.0 and 8.0. It is gram negative and rod shaped; it’s also a chemoorganotroph. This bacteria forms spores after a fruiting body is made. Also, M. xanthus is a social bacteria that usually lives in swarms. These swarms hunt in a “wolf pack” fashion. It utilizes a form of motility called gliding to get around. These characteristics make it an interesting microbe to research.
The most remarkable behavior of M. xanthus is the formation of a fruiting body. Fruiting body formation usually occurs during times of starvation. Around 100,000 (!) cells congregate and form a spherical body of cells over the course of several hours. The cells coordinate their rippling movements by intercellular communication using A signal, B signal, and C signal. However, it is hypothesized that the cells follow the slime trails by chemotaxis to aggregate. Once the fruiting body is formed, the interior cells start to undergo chemical changes. A few of the cells form spherical spores, but many of the cells lyse to provide nutrients for the cells forming spores. Many other myxobacteria also form fruiting bodies.
Swarming is another neat feature of M. xanthus. M. xanthus has two kinds of movements: A-motility (adventurous) and S-motility (social). A-motility is movement independent of the swarm. This occurs when the cell is not in close contact with another. S-motility occurs when the bacteria are close to one another. The swarm hunts in a “wolf pack” fashion. The swarm is attracted to its prey, usually other soil bacteria, and it moves as a group to surround it. Then, they release antibiotics and enzymes as a group to kill and digest the prey.
The last behavior of M. xanthus to be discussed is gliding. Recently, there was research done by Andrey Dobrynin, a polymer scientist at the University of Connecticut in Storrs on the gliding mechanism of bacteria. He discovered that movement was actually caused by the slime secretions of M. xanthus. Polysaccharides are produced in nozzles at either end of the bacterium. Whenever it is produced faster than it can escape, pressure builds up, and the slime is ejected forcefully causing thrust. There are about 250 of thee nozzles at either end of M. xanthus. It can dart either forward of backward at up to10 µm/s. “They’re little rockets,” says Andrey Dobrynin.
There is much to be discovered about the social M. xanthus. However, research is currently being done to further unravel the mysterious intercellular communications. Hopefully, we will learn more about this bacteria in the near future.
References
http://cmgm.stanford.edu/~kaiserla/about_myxo/about_myxococcus.html
http://myxococcus.syr.edu/Research/index.htm
http://biology.kenyon.edu/Microbial_Biorealm/bacteria/proteobacteria/myxococcus/myxococcus.htm
http://www.blackwell-synergy.com/doi/pdf/10.1046/j.1365-2958.1997.4261783.x?cookieSet=1
*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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