Myxobacteria Explained

The myxobacteria ("slime bacteria") are a group of bacteria that predominantly live in the soil and feed on insoluble organic substances. The myxobacteria have very large genomes relative to other bacteria, e.g. 9–10 million nucleotides except for Anaeromyxobacter[1] and Vulgatibacter.[2] One species of myxobacteria, Minicystis rosea,[3] has the largest known bacterial genome with over 16 million nucleotides. The second largest is another myxobacteria Sorangium cellulosum.[4] [5]

Myxobacteria can move by gliding.[6] They typically travel in swarms (also known as wolf packs), containing many cells kept together by intercellular molecular signals. Individuals benefit from aggregation as it allows accumulation of the extracellular enzymes that are used to digest food; this in turn increases feeding efficiency. Myxobacteria produce a number of biomedically and industrially useful chemicals, such as antibiotics, and export those chemicals outside the cell.[7]

Myxobacteria are used to study the polysaccharide production in gram-negative bacteria like the model Myxococcus xanthus which have four different mechanisms[8] of polysaccharide secretion and where a new Wzx/Wzy mechanism producing a new polysaccharide was identified in 2020.

Myxobacteria are also good models to study the multicellularity in the bacterial world.[9]

Life cycle

When nutrients are scarce, myxobacterial cells aggregate into fruiting bodies (not to be confused with those in fungi), a process long-thought to be mediated by chemotaxis but now considered to be a function of a form of contact-mediated signaling.[10] [11] These fruiting bodies can take different shapes and colors, depending on the species. Within the fruiting bodies, cells begin as rod-shaped vegetative cells, and develop into rounded myxospores with thick cell walls. These myxospores, analogous to spores in other organisms, are more likely to survive until nutrients are more plentiful. The fruiting process is thought to benefit myxobacteria by ensuring that cell growth is resumed with a group (swarm) of myxobacteria, rather than as isolated cells. Similar life cycles have developed among certain amoebae, called cellular slime molds.

At a molecular level, initiation of fruiting body development in Myxococcus xanthus is regulated by Pxr sRNA.[12] [13]

Myxobacteria such as Myxococcus xanthus and Stigmatella aurantiaca are used as model organisms for the study of development.

It has been suggested that the last common ancestor of myxobacteria was an aerobe and that their anaerobic predecessors lived syntrophically with early eukaryotes.[14]

Clinical use

Metabolites secreted by Sorangium cellulosum known as epothilones have been noted to have antineoplastic activity. This has led to the development of analogs which mimic its activity. One such analog, known as Ixabepilone is a U.S. Food and Drug Administration approved chemotherapy agent for the treatment of metastatic breast cancer.[15]

Myxobacteria are also known to produce gephyronic acid, an inhibitor of eukaryotic protein synthesis and a potential agent for cancer chemotherapy.[16]

Phylogeny

The currently accepted taxonomy is based on the List of Prokaryotic names with Standing in Nomenclature (LPSN)[17] and National Center for Biotechnology Information (NCBI)[18]

See also

External links

Notes and References

  1. Thomas SH, Wagner RD, Arakaki AK, Skolnick J, Kirby JR, Shimkets LJ, Sanford RA, Löffler FE . The mosaic genome of Anaeromyxobacter dehalogenans strain 2CP-C suggests an aerobic common ancestor to the delta-proteobacteria . PLOS ONE . 3 . 5 . e2103 . May 2008 . 18461135 . 2330069 . 10.1371/journal.pone.0002103 . 2008PLoSO...3.2103T . free .
  2. 2015-08-19. Vulgatibacter incomptus strain DSM 27710, complete genome. en-US.
  3. Shilpee Pal, Gaurav Sharma & Srikrishna Subramanian . 2021-09-13 . Complete genome sequence and identification of polyunsaturated fatty acid biosynthesis genes of the myxobacterium Minicystis rosea DSM 24000T . BMC Genomics . en-US . 22 . 1. 655 . 10.1186/s12864-021-07955-x. 34511070. 8436480 . free .
  4. Schneiker S, Perlova O, Kaiser O, Gerth K, Alici A, Altmeyer MO, Bartels D, Bekel T, Beyer S, Bode E, Bode HB, Bolten CJ, Choudhuri JV, Doss S, Elnakady YA, Frank B, Gaigalat L, Goesmann A, Groeger C, Gross F, Jelsbak L, Jelsbak L, Kalinowski J, Kegler C, Knauber T, Konietzny S, Kopp M, Krause L, Krug D, Linke B, Mahmud T, Martinez-Arias R, McHardy AC, Merai M, Meyer F, Mormann S, Muñoz-Dorado J, Perez J, Pradella S, Rachid S, Raddatz G, Rosenau F, Rückert C, Sasse F, Scharfe M, Schuster SC, Suen G, Treuner-Lange A, Velicer GJ, Vorhölter FJ, Weissman KJ, Welch RD, Wenzel SC, Whitworth DE, Wilhelm S, Wittmann C, Blöcker H, Pühler A, Müller R. 6 . Complete genome sequence of the myxobacterium, Sorangium cellulosum . Nat. Biotechnol. . 25 . 11 . 1281–9 . November 2007 . 17965706 . 10.1038/nbt1354 . free.
  5. Land M, Hauser L, Jun SR, Nookaew I, Leuze MR, Ahn TH, Karpinets T, Lund O, Kora G, Wassenaar T, Poudel S, Ussery DW . Insights from 20 years of bacterial genome sequencing . Funct. Integr. Genomics . 15 . 2 . 141–61 . March 2015 . 25722247 . 4361730 . 10.1007/s10142-015-0433-4.
  6. Mauriello EM, Mignot T, Yang Z, Zusman DR . Gliding motility revisited: how do the myxobacteria move without flagella? . Microbiol. Mol. Biol. Rev. . 74 . 2 . 229–49 . June 2010 . 20508248 . 2884410 . 10.1128/MMBR.00043-09.
  7. Reichenbach H . Myxobacteria, producers of novel bioactive substances . J. Ind. Microbiol. Biotechnol. . 27 . 3 . 149–56 . September 2001 . 11780785 . 10.1038/sj.jim.7000025 . 34964313. free .
  8. Islam ST, Vergara Alvarez I, Saïdi F, Guiseppi A, Vinogradov E, Sharma G, Espinosa L, Morrone C, Brasseur G, Guillemot JF, Benarouche A, Bridot JL, Ravicoularamin G, Cagna A, Gauthier C, Singer M, Fierobe HP, Mignot T, Mauriello EM . 6 . Modulation of bacterial multicellularity via spatio-specific polysaccharide secretion . PLOS Biology . 18 . 6 . e3000728 . June 2020 . 32516311 . 7310880 . 10.1371/journal.pbio.3000728 . free .
  9. Islam ST, Vergara Alvarez I, Saïdi F, Guiseppi A, Vinogradov E, Sharma G, Espinosa L, Morrone C, Brasseur G, Guillemot JF, Benarouche A, Bridot JL, Ravicoularamin G, Cagna A, Gauthier C, Singer M, Fierobe HP, Mignot T, Mauriello EM . 6 . Modulation of bacterial multicellularity via spatio-specific polysaccharide secretion . PLOS Biology . 18 . 6 . e3000728 . June 2020 . 32516311 . 7310880 . 10.1371/journal.pbio.3000728 . free .
  10. Kiskowski MA, Jiang Y, Alber MS . Role of streams in myxobacteria aggregate formation . Phys Biol . 1 . 3–4 . 173–83 . December 2004 . 16204837 . 10.1088/1478-3967/1/3/005 . 2004PhBio...1..173K . 18846289 .
  11. Sozinova O, Jiang Y, Kaiser D, Alber M . A three-dimensional model of myxobacterial aggregation by contact-mediated interactions . Proc. Natl. Acad. Sci. U.S.A. . 102 . 32 . 11308–12 . August 2005 . 16061806 . 1183571 . 10.1073/pnas.0504259102 . 2005PNAS..10211308S . free .
  12. Yu YT, Yuan X, Velicer GJ . Adaptive evolution of an sRNA that controls Myxococcus development . Science . 328 . 5981 . 993 . May 2010 . 20489016 . 3027070 . 10.1126/science.1187200 . 2010Sci...328..993Y .
  13. Fiegna F, Yu YT, Kadam SV, Velicer GJ . Evolution of an obligate social cheater to a superior cooperator . Nature . 441 . 7091 . 310–4 . May 2006 . 16710413 . 10.1038/nature04677 . 2006Natur.441..310F . 4371886 .
  14. Evolution of bacterial steroid biosynthesis and its impact on eukaryogenesis . Hoshino . Y. . Gaucher . E.A. . PNAS . 118 . 25 . 2021 . e2101276118 . 10.1073/pnas.2101276118. 0027-8424 . 34131078. 8237579 . free .
  15. Web site: FDA Approval for Ixabepilone. . National Cancer Institute.
  16. Sasse F, Steinmetz H, Höfle G, Reichenbach H . Gephyronic acid, a novel inhibitor of eukaryotic protein synthesis from Archangium gephyra (myxobacteria). Production, isolation, physico-chemical and biological properties, and mechanism of action . J. Antibiot. . 48 . 1 . 21–5 . January 1995 . 7868385 . 10.7164/antibiotics.48.21 . free .
  17. Web site: J.P. Euzéby . Deltaproteobacteria . 2022-09-09 . List of Prokaryotic names with Standing in Nomenclature (LPSN).
  18. Web site: Sayers. Deltaproteobacteria . 2022-09-09 . National Center for Biotechnology Information (NCBI) taxonomy database . et al..
  19. Web site: The LTP . 20 November 2023.
  20. Web site: LTP_all tree in newick format. 20 November 2023.
  21. Web site: LTP_08_2023 Release Notes. 20 November 2023.
  22. Web site: GTDB release 08-RS214 . Genome Taxonomy Database. 10 May 2023.
  23. Web site: bac120_r214.sp_label . Genome Taxonomy Database. 10 May 2023.
  24. Web site: Taxon History . Genome Taxonomy Database. 10 May 2023.

This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Myxobacteria".

Except where otherwise indicated, Everything.Explained.Today is © Copyright 2009-2024, A B Cryer, All Rights Reserved. Cookie policy.