Imaging Bacterial Interspecies Chemical Interactions by Surface-Enhanced Raman Scattering

Area of Science:

• Microbiology
• Spectroscopy
• Chemical Biology

Background:

• Microbial interactions are mediated by bioactive compounds.
• Visualizing these molecules in vivo is crucial for understanding microbial ecology.
• Current methods may require sample preparation, limiting real-time analysis.

Purpose of the Study:

• To demonstrate the application of surface-enhanced Raman scattering (SERS) spectroscopy for in vivo visualization of microbial metabolites.
• To simultaneously detect quorum-sensing-regulated compounds from interacting bacterial species.
• To provide insights into interspecies chemical communication in microbial cocultures.

Main Methods:

• Utilized surface-enhanced Raman scattering (SERS) spectroscopy.
• Grew Pseudomonas aeruginosa and Chromobacterium violaceum in coculture on plasmonic substrates.
• Combined SERS with gene expression analysis.
• Performed spatiotemporal imaging of microbial metabolites in live colonies.

Main Results:

• Successfully visualized pyocyanin and violacein produced by P. aeruginosa and C. violaceum, respectively.
• Mapped the spatial distribution of these metabolites within the coculture.
• Observed chemical interactions and metabolite expression resulting from interspecies communication.
• Demonstrated the ability to analyze microbial chemotypes without sample preparation.

Conclusions:

• SERS is a powerful, sensitive, and cost-effective tool for analyzing microbial chemotypes.
• The developed approach enables spatiotemporal imaging of metabolites in live microbial colonies.
• This method provides valuable insights into the chemical interplay between interacting bacterial species.