1887

Abstract

is a soil bacterium that undergoes differentiation to form cysts that are resistant to desiccation. Upon induction of cyst formation, the bacterium synthesizes alkylresorcinols that are present in cysts but not in vegetative cells. Alternative sigma factors play important roles in differentiation. In , AlgU (sigma E) is involved in controlling the loss of flagella upon induction of encystment. We investigated the involvement of the sigma factor RpoS in cyst formation in . We analysed the transcriptional regulation of the gene by PsrA, the main regulator of in species, which are closely related to . Inactivation of resulted in the inability to form cysts resistant to desiccation and to produce cyst-specific alkylresorcinols, whereas inactivation of reduced by 50 % both production of alkylresorcinols and formation of cysts resistant to desiccation. Electrophoretic mobility shift assays revealed specific binding of PsrA to the promoter region and that inactivation of reduced transcription by 60 %. These results indicate that RpoS and PsrA are involved in regulation of encystment and alkylresorcinol synthesis in .

Funding
This study was supported by the:
  • PAPIIT (Award IN222809-2)
  • CONACyT
Loading

Article metrics loading...

/content/journal/micro/10.1099/mic.0.046268-0
2011-06-01
2024-03-29
Loading full text...

Full text loading...

/deliver/fulltext/micro/157/6/1685.html?itemId=/content/journal/micro/10.1099/mic.0.046268-0&mimeType=html&fmt=ahah

References

  1. Bali A., Blanco G., Hill S., Kennedy C. ( 1992). Excretion of ammonium by a nifL mutant of Azotobacter vinelandii fixing nitrogen. Appl Environ Microbiol 58:1711–1718[PubMed]
    [Google Scholar]
  2. Campos M., Martínez-Salazar J. M., Lloret L., Moreno S., Núñez C., Espín G., Soberón-Chávez G. ( 1996). Characterization of the gene coding for GDP-mannose dehydrogenase (algD) from Azotobacter vinelandii. J Bacteriol 178:1793–1799[PubMed]
    [Google Scholar]
  3. Castañeda M., Sánchez J., Moreno S., Núñez C., Espín G. ( 2001). The global regulators GacA and sigma(S) form part of a cascade that controls alginate production in Azotobacter vinelandii. J Bacteriol 183:6787–6793 [View Article][PubMed]
    [Google Scholar]
  4. Gaona G., Núñez C., Goldberg J. B., Linford A. S., Nájera R., Castañeda M., Guzmán J., Espín G., Soberón-Chávez G. ( 2004). Characterization of the Azotobacter vinelandii algC gene involved in alginate and lipopolysaccharide production. FEMS Microbiol Lett 238:199–206[PubMed]
    [Google Scholar]
  5. Hanahan D. ( 1983). Studies on transformation of Escherichia coli with plasmids. J Mol Biol 166:57–580 [View Article][PubMed]
    [Google Scholar]
  6. Kang Y., Nguyen D. T., Son M. S., Hoang T. T. ( 2008). The Pseudomonas aeruginosa PsrA responds to long-chain fatty acid signals to regulate the fadBA5 beta-oxidation operon. Microbiology 154:1584–1598 [View Article][PubMed]
    [Google Scholar]
  7. Kang Y., Lunin V. V., Skarina T., Savchenko A., Schurr M. J., Hoang T. T. ( 2009). The long-chain fatty acid sensor, PsrA, modulates the expression of rpoS and the type III secretion exsCEBA operon in Pseudomonas aeruginosa. Mol Microbiol 73:120–136 [View Article][PubMed]
    [Google Scholar]
  8. Kennedy C., Gamal R., Humphrey R., Ramos J., Brigle K., Dean D. ( 1986). The nifH, nifM, and nifN genes of Azotobacter vinelandii: characterization by Tn5 mutagenesis and isolation from pLARF1 gene banks. Mol Gen Genet 205:318–325 [View Article]
    [Google Scholar]
  9. Kojic M., Venturi V. ( 2001). Regulation of rpoS gene expression in Pseudomonas: involvement of a TetR family regulator. J Bacteriol 183:3712–3720 [View Article][PubMed]
    [Google Scholar]
  10. Kojic M., Aguilar C., Venturi V. ( 2002). TetR family member psrA directly binds the Pseudomonas rpoS and psrA promoters. J Bacteriol 184:2324–2330 [View Article][PubMed]
    [Google Scholar]
  11. Kovach M. E., Elzer P. H., Hill D. S., Robertson G. T., Farris M. A., Roop R. M. II, Peterson K. M. ( 1995). Four new derivatives of the broad-host-range cloning vector pBBR1MCS, carrying different antibiotic-resistance cassettes. Gene 166:175–176 [View Article][PubMed]
    [Google Scholar]
  12. León R., Espín G. ( 2008). flhDC, but not fleQ, regulates flagella biogenesis in Azotobacter vinelandii, and is under AlgU and CydR negative control. Microbiology 154:1719–1728 [View Article][PubMed]
    [Google Scholar]
  13. Lin L. P., Sadoff H. L. ( 1968). Encystment and polymer production by Azotobacter vinelandii in the presence of β-hydroxybutyrate. J Bacteriol 95:2336–2343[PubMed]
    [Google Scholar]
  14. Mejía-Ruíz H., Moreno S., Guzmán J., Nájera R., León R., Soberón-Chávez G., Espín G. ( 1997). Isolation and characterization of an Azotobacter vinelandii algK mutant. FEMS Microbiol Lett 156:101–106 [View Article][PubMed]
    [Google Scholar]
  15. Moreno S., Nájera R., Guzmán J., Soberón-Chávez G., Espín G. ( 1998). Role of alternative sigma factor algU in encystment of Azotobacter vinelandii. J Bacteriol 180:2766–2769[PubMed]
    [Google Scholar]
  16. Navarro Llorens J. M., Tormo A., Martínez-García E. ( 2010). Stationary phase in gram-negative bacteria. FEMS Microbiol Rev 34:476–495 [View Article][PubMed]
    [Google Scholar]
  17. Noguez R., Segura D., Moreno S., Hernandez A., Juárez K., Espín G. ( 2008). Enzyme INtr, NPr and IIANtr are involved in regulation of the poly-β-hydroxybutyrate biosynthetic genes in Azotobacter vinelandii. J Mol Microbiol Biotechnol 15:244–254 [View Article][PubMed]
    [Google Scholar]
  18. Page W. J., von Tigerstrom M. ( 1978). Induction of transformation competence in Azotobacter vinelandii iron-limited cultures. Can J Microbiol 24:1590–1594 [View Article][PubMed]
    [Google Scholar]
  19. Peralta-Gíl M., Segura D., Guzmán J., Servín-González L., Espín G. ( 2002). Expression of the Azotobacter vinelandii poly-beta-hydroxybutyrate biosynthetic phbBAC operon is driven by two overlapping promoters and is dependent on the transcriptional activator PhbR. J Bacteriol 184:5672–5677 [View Article][PubMed]
    [Google Scholar]
  20. Reusch R. N., Sadoff H. L. ( 1983). Novel lipid components of the Azotobacter vinelandii cyst membrane. Nature 302:268–270 [View Article][PubMed]
    [Google Scholar]
  21. Sadoff H. L. ( 1975). Encystment and germination in Azotobacter vinelandii. Bacteriol Rev 39:516–539[PubMed]
    [Google Scholar]
  22. Sambrook J., Fritsch E. E., Maniatis T. ( 1989). Molecular Cloning: a Laboratory Manual, 2nd edn. Cold Spring Harbor, NY: Cold Spring Harbor Laboratory;
    [Google Scholar]
  23. Sandercock J. R., Page W. J. ( 2008). RpoS expression and the general stress response in Azotobacter vinelandii during carbon and nitrogen diauxic shifts. J Bacteriol 190:946–953 [View Article][PubMed]
    [Google Scholar]
  24. Schuster M., Hawkins A. C., Harwood C. S., Greenberg E. P. ( 2004). The Pseudomonas aeruginosa RpoS regulon and its relationship to quorum sensing. Mol Microbiol 51:973–985 [View Article][PubMed]
    [Google Scholar]
  25. Segura D., Cruz T., Espín G. ( 2003). Encystment and alkylresorcinol production by Azotobacter vinelandii strains impaired in poly-beta-hydroxybutyrate synthesis. Arch Microbiol 179:437–443[PubMed]
    [Google Scholar]
  26. Segura D., Vite O., Romero Y., Moreno S., Castañeda M., Espín G. ( 2009). Isolation and characterization of Azotobacter vinelandii mutants impaired in alkylresorcinol synthesis: alkylresorcinols are not essential for cyst desiccation resistance. J Bacteriol 191:3142–3148 [View Article][PubMed]
    [Google Scholar]
  27. Setubal J. C., dos Santos P., Goldman B. S., Ertesvåg H., Espín G., Rubio L. M., Valla S., Almeida N. F., Balasubramanian D. et al. ( 2009). Genome sequence of Azotobacter vinelandii, an obligate aerobe specialized to support diverse anaerobic metabolic processes. J Bacteriol 191:4534–4545 [View Article][PubMed]
    [Google Scholar]
  28. Shen D. K., Filopon D., Kuhn L., Polack B., Toussaint B. ( 2006). PsrA is a positive transcriptional regulator of the type III secretion system in Pseudomonas aeruginosa. Infect Immun 74:1121–1129 [View Article][PubMed]
    [Google Scholar]
  29. Venturi V. ( 2003). Control of rpoS transcription in Escherichia coli and Pseudomonas: why so different?. Mol Microbiol 49:1–9 [View Article][PubMed]
    [Google Scholar]
  30. Wyss O., Neumnn M. G., Socolofsky M. D. ( 1961). Development and germination of the Azotobacter cyst. J Biophys Biochem Cytol 10:555–565 [View Article][PubMed]
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/micro/10.1099/mic.0.046268-0
Loading
/content/journal/micro/10.1099/mic.0.046268-0
Loading

Data & Media loading...

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error