Osmotic stress and phosphate limitation alter production of cell-to-cell signal molecules and rhamnolipid biosurfactant by Pseudomonas aeruginosa.

Abstract

In Pseudomonas aeruginosa, rhamnolipid production is controlled by the quorum-sensing system RhlRI, which itself depends on LasRI. These systems use cell-to-cell signal molecules: N-butyryl-l-homoserine lactone (C4-HSL) and N-(3-oxododecanoyl)-l-homoserine lactone (3OC(12)-HSL), respectively. Whereas both HSLs were produced in M63 medium, rhamnolipid synthesis was not achieved. Phosphate limitation reduced the HSL concentrations, while allowing rhamnolipid production. Hyperosmotic shock applied during the exponential growth phase stopped the accumulation of 3OC(12)-HSL, and prevented C4-HSL and rhamnolipid production. These defects result from lower expression of genes involved in C4-HSL and rhamnolipid syntheses. The osmoprotectant glycine betaine partially restored C4-HSL and rhamnolipid production.

• Authors: Alexis Bazire, Alexandra Dheilly, Farès Diab, Danièle Morin, Mohamed Jebbar, Dominique Haras, Alain Dufour
• Journal: FEMS microbiology letters (FEMS Microbiol Lett) Vol. 253 Issue 1 Pg. 125-31 (Dec 01 2005) ISSN: 0378-1097 [Print] England
• PMID: 16239086 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• DNA, Bacterial
• Glycolipids
• Phosphates
• Surface-Active Agents
• rhamnolipid
• homoserine lactone
• Betaine
• 4-Butyrolactone

Topics

• 4-Butyrolactone (analogs & derivatives, biosynthesis)
• Base Sequence
• Betaine (pharmacology)
• DNA, Bacterial (genetics)
• Glycolipids (biosynthesis)
• Humans
• Kinetics
• Osmotic Pressure
• Phosphates (metabolism)
• Pseudomonas aeruginosa (drug effects, genetics, metabolism, pathogenicity)
• Signal Transduction
• Surface-Active Agents (metabolism)