Myxococcus

Myxococcus
Fruiting bodies of M. xanthus
Scientific classification Edit this classification
Domain: Bacteria
Phylum: Myxococcota
Class: Myxococcia
Order: Myxococcales
Family: Myxococcaceae
Genus: Myxococcus
Thaxter 1892
Type species
Myxococcus fulvus
(Cohn 1875) Jahn 1911
Species

See text

Synonyms
  • Myxococcus section "Simplices" Jahn 1911
  • Myxococcus section "Stipitatae" Jahn 1911

Myxococcus is a genus of bacteria in the family Myxococcaceae. Myxococci are Gram-negative, spore-forming, chemoorganotrophic, obligate aerobes. They are elongated rods with rounded or tapered ends, and they are nonflagellated. The cells move by gliding and can predate other bacteria. The genus has been isolated from soil.

At least eleven species had been identified with confidence by late 2020 and each had been characterised to some extent. As well as using traditional biochemical tests, strains of some species had been compared using whole genome sequences. This approach has provided evidence that the genus, like most bacterial genera, has a core set of genes found in all members of the genus, along with others that are confined to particular species. The identity of Myxococcus species therefore continues to change. An example where taxonomy may be changed is that comparisons of genome sequences and biochemical tests indicated that M. xanthus and M. virescens were not distinguishable.[1][2]

One notable characteristic of Myxococcus is its formation of fruiting bodies. Myxococcus are known to form fruiting bodies using chemical signals. The cells communicate with each other, and in response to stress factors, most often starvation, begin to form fruiting bodies. These fruiting bodies then allow Myxococcus to transform into round spores resistant to the environment.[3] The genetic programs underlying fruiting body formation in the Myxococci exhibit an unexpected level of plasticity, strongly suggesting that the genetic program underlying fruiting body formation in various Myxococci is not conserved, leading to diverse reactions in all Myxococcus species.[4] Rather than chemotaxis used by other microorganisms for cell-cell communication, Myxococcus, specifically M. xanthus, a species of Myxococcus, has been found to use direct cell-to-cell communication to form fruiting bodies.[3]

In addition, Myxococcus prey interacts with one another by sending quorum signals using acyl homoserine lactones (AHLs). It was discovered that AHLs increased some Myxococcus colonies' predatory behavior and growth rates. Therefore, the predatory behavior of these Myxococcus bacteria appears to be enhanced by the presence of xenic quorum signaling molecules. Some Myxococcus bacteria employ AHLs as indicators of nearby prey, possibly listening in on talks between prey creatures in the wild.[5]

This cooperation between different individual Myxococcus allows them to act as a singular organism and perform functions as such, including but not limited to homeostasis repair. While fruiting body development occurs through the Myxococcus genus, it can take on a variety of structures, and dome-shaped mounds have been observed in some species.[6] Social interactions are major in the myxobacteria's life cycle. In significant groupings compared to wolf packs, cells prey on other bacteria during vegetative growth. When starved, cells produce a macroscopic fruiting body dense with spores. The current state of knowledge on cell-cell signaling during development is reflected in these behavioral activities.[7]

Myxococcus is a single celled predatory bacteria that are facultative bacteria. Myxococcus are social microbes and often seen as exhibiting “wolf-pack” behavior.[8] They are able to communicate with each other via quorum sensing. Myxococcus are seen as predatory microbial communities because of their behavior. They are able to form several distinct multicellular structures. Myxococcus are found in soil. Single cells combine and form large clusters using quorum sensing. When nutrients are unavailable, these cells become fruiting bodies that contain approximately 50,000 cells.[9] One study found that after placing the bacteria in starving conditions they aggregated into mounds of 100,000 cells.[10]

  1. ^ Cite error: The named reference ChambersEtAl2020 was invoked but never defined (see the help page).
  2. ^ Sharma, Gaurav; Narwani, Tarun; Subramanian, Srikrishna (2016). "Complete Genome Sequence and Comparative Genomics of a Novel Myxobacterium Myxococcus hansupus". PLOS ONE. 11 (2): e0148593. Bibcode:2016PLoSO..1148593S. doi:10.1371/journal.pone.0148593. PMC 4765838. PMID 26900859.
  3. ^ a b Sozinova, Olga; Jiang, Yi; Kaiser, Dale; Alber, Mark (14 November 2006). "A three-dimensional model of myxobacterial fruiting-body formation". Proceedings of the National Academy of Sciences. 103 (46): 17255–17259. Bibcode:2006PNAS..10317255S. doi:10.1073/pnas.0605555103. PMC 1859919. PMID 17088558.
  4. ^ Huntley, Stuart; Hamann, Nils; Wegener-Feldbrügge, Sigrun; Treuner-Lange, Anke; Kube, Michael; Reinhardt, Richard; Klages, Sven; Müller, Rolf; Ronning, Catherine M.; Nierman, William C.; Søgaard-Andersen, Lotte (February 2011). "Comparative Genomic Analysis of Fruiting Body Formation in Myxococcales". Molecular Biology and Evolution. 28 (2): 1083–1097. doi:10.1093/molbev/msq292. PMID 21037205.
  5. ^ Lloyd, Daniel G.; Whitworth, David E. (2017-03-14). "The Myxobacterium Myxococcus xanthus Can Sense and Respond to the Quorum Signals Secreted by Potential Prey Organisms". Frontiers in Microbiology. 8: 439. doi:10.3389/fmicb.2017.00439. PMC 5348527. PMID 28352265.
  6. ^ Cao, Pengbo; Dey, Arup; Vassallo, Christopher N.; Wall, Daniel (November 2015). "How Myxobacteria Cooperate". Journal of Molecular Biology. 427 (23): 3709–3721. doi:10.1016/j.jmb.2015.07.022. PMC 4658263. PMID 26254571.
  7. ^ Shimkets, Lawrence J. (October 1999). "Intercellular Signaling During Fruiting-Body Development of Myxococcus xanthus". Annual Review of Microbiology. 53 (1): 525–549. doi:10.1146/annurev.micro.53.1.525. PMID 10547700.
  8. ^ Marshall, Rupert C.; Whitworth, David E. (April 2019). "Is 'Wolf-Pack' Predation by Antimicrobial Bacteria Cooperative? Cell Behaviour and Predatory Mechanisms Indicate Profound Selfishness, Even when Working Alongside Kin". BioEssays. 41 (4): 1800247. doi:10.1002/bies.201800247. PMID 30919490. S2CID 85544906.
  9. ^ Curtis, Patrick D.; Taylor, Rion G.; Welch, Roy D.; Shimkets, Lawrence J. (December 2007). "Spatial organization of Myxococcus xanthus during fruiting body formation". Journal of Bacteriology. 189 (24): 9126–9130. doi:10.1128/JB.01008-07. PMC 2168639. PMID 17921303.
  10. ^ Sliusarenko, Oleksii; Zusman, David R.; Oster, George (15 January 2007). "Aggregation during Fruiting Body Formation in Myxococcus xanthus Is Driven by Reducing Cell Movement". Journal of Bacteriology. 189 (2): 611–619. doi:10.1128/JB.01206-06. PMC 1797407. PMID 17098901.