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A Fluorescence-based Method to Study Bacterial Gene Regulation in Infected Tissues
Published on: February 19, 2019
A quorum-sensing system in the free-living photosynthetic bacterium Rhodobacter sphaeroides
A Puskas1, E P Greenberg, S Kaplan
1Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, Houston 77224, USA.
Journal of Bacteriology
|December 11, 1997
Summary
Rhodobacter sphaeroides possesses a novel quorum-sensing system, utilizing a unique acylhomoserine lactone signal. This discovery reveals new insights into bacterial communication and multicellular behavior.
Area of Science:
- Microbiology
- Bacterial Genetics
- Molecular Biology
Background:
- Rhodobacter sphaeroides is a metabolically complex, free-living photoheterotrophic bacterium.
- Quorum sensing is a cell-to-cell communication mechanism common in Gram-negative bacteria, typically involving luxR and luxI homologs and acylhomoserine lactone signals.
Purpose of the Study:
- To investigate the presence and components of a quorum-sensing system in Rhodobacter sphaeroides.
- To characterize the novel acylhomoserine lactone signal and its role in bacterial behavior.
Main Methods:
- Identification and characterization of luxR and luxI homologs (cerR and cerI) in R. sphaeroides.
- Inactivation of the cerI gene to observe phenotypic changes.
- Analysis of quorum-sensing signal addition to mutant cultures.
Main Results:
- R. sphaeroides possesses a quorum-sensing system regulated by cerI, which synthesizes 7,8-cis-N-(tetradecenoyl)homoserine lactone.
- Inactivation of cerI leads to mucoid colony formation and cell aggregation in liquid cultures.
- The observed aggregation phenotype in cerI mutants is reversible upon addition of the synthetic signal molecule.
Conclusions:
- Rhodobacter sphaeroides utilizes a unique quorum-sensing system with a novel acylhomoserine lactone signal.
- This system controls phenotypes such as cell aggregation, distinct from those observed in other bacterial quorum-sensing systems.
- The findings expand our understanding of bacterial communication and multicellularity in diverse bacterial species.
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