Stigmatella aurantiaca


Stigmatella aurantiaca is a member of myxobacteria, a group of gram-negative bacteria with a complex developmental life cycle

Contents

  • 1 Classification
  • 2 Life cycle
  • 3 Genome structure
  • 4 Cell structure
  • 5 Ecology
  • 6 Current Research
    • 61 Model system for development
    • 62 Natural secondary metabolites
  • 7 References
  • 8 External links

Classification

The bacterial nature of this organism was recognized by Thaxter in 1892,[2] who grouped it among the Chrondromyces It had been described several times before, but had been misclassified as a member of the fungi imperfecti[3] More recent investigations have shown that, contrary to Thaxter's classification, this organism is not closely related to Chrondromyces, and Stigmatella is currently recognized as a separate genus[3] Of the three major subgroups of the myxobacteria, Myxococcus, Nannocystis, and Chrondromyces, Stigmatella is most closely aligned with Myxococcus[4][5]

Life cycle

Three species of myxobacteria: Chondromyces crocatus figs 7–11, Stigmatella aurantiaca figs 12–19 and Melittangium lichenicola figs 20–23

S aurantiaca, like other myxobacterial species, has a complex life cycle including social gliding swarming, fruiting body formation, and predatory feeding behaviors The bacteria do not swim, but glide on surfaces leaving slime trails, forming a mobile biofilm It commonly grows on the surface of rotting soft woods or fungi, where it may form bright orange patches

During the vegetative portion of their life cycles, swarming enables coordinated masses of myxobacteria to pool their secretions of extracellular digestive enzymes which are used to kill and consume prey microorganisms, a bacterial "wolfpack" effect[6] The best studied of the myxobacteria, Myxococcus xanthus, has been shown to actively surround prey organisms, trapping them in pockets where they can be consumed Roaming flares of M xanthus can detect clumps of prey bacteria at a distance, making turns towards the clumps and moving directly towards them[7]

Like other myxobacterial species, S aurantiaca survives periods of starvation by undergoing a developmental process whereby the individuals of a swarm aggregate to form fruiting bodies not to be confused with those in fungi Within the fruiting bodies, a certain fraction of the cells differentiate into myxospores, which are dormant cells resistant to drying and temperatures up to 90 °C[3] Differentiation into fruiting bodies appears to be mediated by contact-mediated signaling[8][9]

Under laboratory growth conditions, the ability to undergo differentiation to form fruiting bodies is rapidly lost unless the cultures are regularly forced to fruit by transferring to starvation media Shaker cultures of S aurantiaca permanently lose the ability to fruit[3]

The complex life cycle of myxobacteria is reminiscent of the life cycle of eukaryotic cellular slime molds

Genome structure

Taxonomic identifier: 378806

See also: NCBI UniProtKB

S aurantiaca DW4/3-1, a common laboratory strain, has been completely sequenced See NCBI record link given above Its circular DNA chromosome consists of 1026 million base pairs and has a GC content of 675% 8407 genes have been identified, coding for 8352 proteins

Cell structure

The vegetative cells of S aurantiaca are elongated rods typically measuring about 5–8 μm long and 07–08 μm wide The fine structure resembles that of other gram negative bacteria The cell surface consists of a cytoplasmic membrane with a typical triple layered organization and a cell wall The cell wall consists of an outer triple layer and third dense monolayer in the periplasm[10]

The myxospores are short, optically refractile rods measuring about 26–35 μm by 09–12 μm The brightly colored, red or orange fruiting bodies comprise 1 to 20 spherical or ovoid cysts measuring 40–60 μm by 25–45 μm on top of a stalk measuring 60 to 140 μ high Each red-brown cyst contains thousands of myxospores surrounded by thick, fibrous capsules[11] Dispersal of cysts is thought to benefit myxobacteria by ensuring that cell growth is resumed with a group swarm of myxobacteria, rather than as isolated cells The stalks consist mostly of tubules which may represent the debris of lysed swarm cells, as well as some unlysed cells; very little fibrous material interpretable as slime is seen[11]

Ecology

S aurantiaca is found on rotting wood or fungi and is only rarely found in soil samples Secreted and non-secreted proteins involved in their feeding behaviors, either identified directly or speculatively identified on the basis of proteome analysis, include enzymes capable of breaking down a wide selection of peptidoglycans, polysaccharides, proteins and other cellular detritus Various other secreted compounds possibly involved in predation include antibiotics such as stigmatellin, which is toxic for yeast and filamentous fungi but not most bacteria,[12] and aurafuron A and B, which inhibits the growth of various filamentous fungi[13]

Stigmatella species hence appear in nature to help decompose otherwise insoluble biological debris It is only distantly related to the cellulolytic myxobacteria,[14] does not produce cellulases, and is strongly bacteriolytic[3] Therefore, Stigmatella consumes organisms that feed on wood rather that feeding on wood directly Besides bacteria, its production of antifungal antibiotics suggests that Stigmatella species may feed on yeasts and fungi as well, or alternatively, may suggest that Stigmatella competes with fungi for shared resources By producing antimicrobial compounds, Stigmatella may play a role in maintaining the balance of the microbial population in its habitat[15]

Current Research

Model system for development

Myxobacteria are distinguished from most bacteria by their remarkable range of social behaviors, and as a result, multiple laboratories have taken up studies of these bacteria as a prokaryotic paradigm for differentiation processes and signal transduction Most studies on social behavior in the myxobacteria have focused on M xanthus, which has provided an excellent system amenable to many classical genetic experimental approaches The fruiting bodies of M xanthus are relatively simple mounds, and the considerably more elaborate fruiting structures produced by S aurantiaca has led to S aurantiaca being considered an excellent complementary system to M xanthus, especially given the advent of contemporary means of genomic analysis Most of the 95 known M xanthus development-specific genes are highly conserved in S aurantiaca Genes for entire signal transduction pathways important for fruiting body formation in M xanthus are conserved in S aurantiaca, whereas only a few are conserved in Anaeromyxobacter dehalogenans, a non-fruiting member of the order Myxococcales[16]

Various genes have been identified in S aurantiaca involved in the process of fruiting body formation, including fbfA, which encodes a polypeptide homologous to chitin synthases,[17] fbfB, a gene encoding a putative galactose oxidase,[18] various genes including those encoding tRNAAsp and tRNAVal located at the attB locus a phage attachment site,[19] and so forth These genes play a variety of roles in the developmental cycle For example, in experiments where the fbFA gene was deactivated, the bacterium formed structured clumps instead of fruiting bodies[17]

To control formation of the elaborate and spatially complex multicellular structure which is the fruiting body, the cells must exchange signals during the entire process In M xanthus, various signal molecules involved in this process have been identified In S aurantiaca, Stevens 1982 identified an extracellular, diffusible signaling molecule pheromone that could substitute for light in stimulating fruiting body maturation[20] A few years later, the structure of this molecule, a hydroxy ketone named stigmolone, was determined by NMR and mass spectroscopy[21]

Besides signaling via exchange of diffusible substances, cell-cell signaling can be mediated by contact through the activity of surface located macromolecules An example of this in S aurantiaca would be the csgA homolog to the M xanthus gene, which is bound to the cell envelope The csgA gene product helps the cells to stay together during development and regulates motility of the cells[22]

Pxr sRNA is a regulatory RNA which downregulates genes responsible for the formation of fruiting bodies in M xanthus, and a homolog has been noted in S aurantiaca[23] Another short nucleic acid that has been speculatively linked to cell-cell recognition is multicopy single-stranded DNA msDNA Sequence comparison of msDNAs from M xanthus, S aurantiaca,[24] and other bacteria reveal conserved and hypervariable domains reminiscent of conserved and hypervariable sequences found in allorecognition molecules[25]

Another means for intercellular signaling could be via the exchange of outer membrane vesicles OMVs These vesicles are produced from the outer membrane of myxobacterial cells and are found in large quantities within bacterial biofilms OMVs appear to play a variety of roles in myxobacterial swarming, predation, and development[26]

Natural secondary metabolites

Natural products have been the source of most of the active ingredients in medicine, and continue to be an important source despite the advent of automated high-throughput screening methods for drug discovery in synthetic compounds[27]

Historically, actinomycetes and fungi have been the major source of microbial secondary metabolites found useful as starting points for the development of new drugs, but the last several decades have seen myxobacteria come to the forefront of drug research The pharmaceutical interest in these organisms comes from their production of a wide variety of structurally unique metabolites with interesting biological activities[28] The epothilones, derived from the myxobacterium Sporangium cellulosum, represent a new, recently approved class of cancer drugs Other myxobacterial compounds of potential pharmaceutical interest include disorazol, tubulysin, rhizopodin, chondramid, the aurafurons, tuscolid, tuscuron, and dawenol, chivosazol, soraphen, myxochelin, and the leupyrrins[28]

S aurantiaca has been the source of several of these bioactive compounds, including myxothiazol, an inhibitor of the electron transport chain,[29] dawenol, a polyene metabolite,[30] stigmatellin, an antifungal agent,[12] the antifungals aurafuron A and B,[13] and the iron siderophores myxochelin A and B[31]

References

  1. ^ Skerman, V B D; McGowan, V; Sneath, P H A 1980 "Approved Lists of Bacterial Names" International Journal of Systematic Bacteriology 30: 225–420 doi:101099/00207713-30-1-225 
  2. ^ Thaxter, R 1892 "On the Myxobacteriaceae, a new order of Schizomycetes" Botanical Gazette 17: 389 doi:101086/326866 JSTOR 2464109 
  3. ^ a b c d e Reichenbach, H; Dworkin, M 1969 "Studies on Stigmatella aurantiaca Myxobacterales" PDF J gen Microbiol 58 1: 3–14 doi:101099/00221287-58-1-3 Retrieved 8 September 2013 
  4. ^ Shimkets, L; Woese, C R 1992 "A phylogenetic analysis of the myxobacteria: Basis for their classification" PDF Proc Natl Acad Sci USA 89 20: 9459–9463 doi:101073/pnas89209459 Retrieved 8 September 2013 
  5. ^ Spröer, Cathrin; Reichenbach, Hans; Stackebrand, Erko 1999 "The correlation between morphological and phylogenetic classification of myxobacteria" PDF International Journal of Systematic Bacteriology 49 3: 1255–1262 doi:101099/00207713-49-3-1255 Retrieved 8 September 2013 
  6. ^ Berleman, James E; Kirby, John R September 2009 "Deciphering the hunting strategy of a bacterial wolfpack" FEMS Microbiol Rev 33 5: 942–957 doi:101111/j1574-6976200900185x PMC 2774760 PMID 19519767 
  7. ^ Shapiro, James A June 1988 "Bacteria as Multicellular Organisms" PDF Scientific American 258 6: 82–89 doi:101038/scientificamerican0688-82 Retrieved 8 September 2013 
  8. ^ Kiskowski MA, Jiang Y, Alber MS 2004 "Role of streams in myxobacteria aggregate formation" Phys Biol 1 3–4: 173–83 doi:101088/1478-3967/1/3/005 PMID 16204837 
  9. ^ Sozinova O, Jiang Y, Kaiser D, Alber M 2005 "A three-dimensional model of myxobacterial aggregation by contact-mediated interactions" Proc Natl Acad Sci USA 102 32: 11308–12 doi:101073/pnas0504259102 PMC 1183571 PMID 16061806 
  10. ^ Reichenbach, Hans; Voelz, Herbert; Dworkin, Martin 1969 "Structural Changes in Stigmatella aurantiaca During Myxospore Induction" PDF J Bacteriol 97 2: 905–911 Retrieved 8 September 2013 
  11. ^ a b Voelz, Herbert; Reichenbach, Hans 1969 "Fine Structure of the Fruiting Bodies of Stigmatella aurantiaca Myxobacterales" PDF Journal of Bacteriology 99 3: 856–866 Retrieved 8 September 2013 
  12. ^ a b Kunze, B; Kemmer, T; Höfle, G; Reichenbach, H 1984 "Stigmatellin, a new antibiotic from Stigmatella aurantiaca Myxobacterales I Production, physico-chemical and biological properties" J Antibiot Tokyo 37 5: 454–461 doi:107164/antibiotics37454 
  13. ^ a b Kunze, B; Reichenbach, H; Müller, R; Höfle, G 2005 "Aurafuron a and B, New Bioactive Polyketides from Stigmatella aurantiaca and Archangium gephyra Myxobacteria" The Journal of Antibiotics 58 4: 244–251 doi:101038/ja200528 PMID 15981410 
  14. ^ Yan, Z C; Wang, B; Li, Y Z; Gong, X; Zhang, H Q; Gao, P J 2003 "Morphologies and Phylogenetic Classification of Cellulolytic Myxobacteria" Systematic and Applied Microbiology 26 1: 104–109 doi:101078/072320203322337380 PMID 12747417 
  15. ^ Dworkin, Martin 2007 "Lingering Puzzles about Myxobacteria" PDF Microbe 2 1: 18–23 Retrieved 11 September 2013 
  16. ^ Huntley, S; Hamann, N; Wegener-Feldbrugge, S; Treuner-Lange, A; Kube, M; Reinhardt, R; Klages, S; Muller, R; Ronning, C M; Nierman, W C; Sogaard-Andersen, L 2010 "Comparative Genomic Analysis of Fruiting Body Formation in Myxococcales" Molecular Biology and Evolution 28 2: 1083–1097 doi:101093/molbev/msq292 PMID 21037205 
  17. ^ a b Silakowski, B; Pospiech, A; Neumann, B; Schairer, U 1996 "Stigmatella aurantiaca Fruiting Body Formation Is Dependent on the fbfA Gene Encoding a Polypeptide Homologous to Chitin Synthases" PDF J Bacteriol 178 23: 6706–6713 Retrieved 9 September 2013 
  18. ^ Silakowski, Barbara; Ehret, Heidi; Schairer, Hans Ulrich 1998 "fbfB, a Gene Encoding a Putative Galactose Oxidase, Is Involved in Stigmatella aurantiaca Fruiting Body Formation" J Bacteriol 180 5: 1241–1247 
  19. ^ Muller, S; Shen, H; Hofmann, D; Schairer, H U; Kirby, J R 2006 "Integration into the Phage Attachment Site, attB, Impairs Multicellular Differentiation in Stigmatella aurantiaca" Journal of Bacteriology 188 5: 1701–1709 doi:101128/JB18851701-17092006 PMC 1426541 PMID 16484181 
  20. ^ Stephens, K; Hegeman, G D; White, D 1982 "Pheromone produced by the myxobacterium Stigmatella aurantiaca" PDF J Bacteriol 149 2: 739–747 Retrieved 9 September 2013 
  21. ^ Plaga, W; Stamm, I; Schairer, H U 1998 "Intercellular signaling in Stigmatella aurantiaca: Purification and characterization of stigmolone, a myxobacterial pheromone" Proceedings of the National Academy of Sciences 95 19: 11263–11267 doi:101073/pnas951911263 
  22. ^ Milosevic, Ana 2003 CsgA, A Putative Signal Molecule of the Myxobacterium Stigmatella aurantiaca Involved in Fruiting: Characterization of the csgA gene and influence of csgA inactivation on development PhD Dissertation PDF Rupertus Carola University of Heidelberg, Germany 
  23. ^ Yu, Y T N; Yuan, X; Velicer, G J 2010 "Adaptive Evolution of an sRNA That Controls Myxococcus Development" Science 328 5981: 993 doi:101126/science1187200 PMC 3027070 PMID 20489016 
  24. ^ Dhundale, A; Lampson, B; Furuichi, T; Inouye, M; Inouye, S 1987 "Structure of msDNA from myxococcus xanthus: Evidence for a long, self-annealing RNA precursor for the covalently linked, branched RNA" Cell 51 6: 1105–1112 doi:101016/0092-86748790596-4 PMID 2446773 
  25. ^ Sherman, L A; Chattopadhyay, S 1993 "The Molecular Basis of Allorecognition" Annual Review of Immunology 11: 385–402 doi:101146/annureviy11040193002125 PMID 8476567 
  26. ^ Whitworth, D E 2011 "Myxobacterial vesicles death at a distance" Advances in Applied Microbiology Advances in Applied Microbiology 75: 1–31 doi:101016/B978-0-12-387046-900001-3 ISBN 9780123870469 PMID 21807244 
  27. ^ Harvey, A 2008 "Natural products in drug discovery" Drug Discovery Today 13 19–20: 894–901 doi:101016/jdrudis200807004 PMID 18691670 
  28. ^ a b Bode, H B; Müller, R 2006 "Analysis of myxobacterial secondary metabolism goes molecular" Journal of Industrial Microbiology & Biotechnology 33 7: 577–588 doi:101007/s10295-006-0082-7 
  29. ^ Silakowski, B; Schairer, H U; Ehret, H; Kunze, B; Weinig, S; Nordsiek, G; Brandt, P; Blöcker, H; Höfle, G; Beyer, S; Müller, R 1999 "New Lessons for Combinatorial Biosynthesis from Myxobacteria THE MYXOTHIAZOL BIOSYNTHETIC GENE CLUSTER OF Stigmatella aurantiaca DW4/3-1" Journal of Biological Chemistry 274 52: 37391–37399 doi:101074/jbc2745237391 PMID 10601310 
  30. ^ Soker, Udo; Kunze, Brigette; Reichenbach, Hans; Hofle, Gerhard 2003 "Dawenol, a New Polyene Metabolite from the Myxobacterium Stigmatella aurantiaca" PDF Z Naturforsch 58b: 1024–1026 
  31. ^ Silakowski, B; Kunze, B; Nordsiek, G; Blöcker, H; Höfle, G; Müller, R 2000 "The myxochelin iron transport regulon of the myxobacterium Stigmatella aurantiaca Sg a15" European Journal of Biochemistry 267 21: 6476–6485 doi:101046/j1432-1327200001740x PMID 11029592 

External links

  • The Myxobacteria Web Page
  • Video: Schwarmentwicklung und Morphogenese bei Myxobakterien
  • Video: Myxobacteria form Fruiting Bodies
  • Video: Myxococcus xanthus preying on an E coli colony
  • Type strain of Stigmatella aurantiaca at BacDive - the Bacterial Diversity Metadatabase


Stigmatella aurantiaca Information about

Stigmatella aurantiaca

Stigmatella aurantiaca
Stigmatella aurantiaca

Stigmatella aurantiaca Information Video


Stigmatella aurantiaca viewing the topic.
Stigmatella aurantiaca what, Stigmatella aurantiaca who, Stigmatella aurantiaca explanation

There are excerpts from wikipedia on this article and video



Random Posts

Social Accounts

Facebook Twitter VK
Copyright © 2014. Search Engine