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Updated: Jun 20, 2025
Author Spotlight: Advancing Research in Microbial Autoaggregation Using Imaging Flow Cytometry
Published on: September 29, 2023
Elucidating bacterial coaggregation through a physicochemical and imaging surface characterization
Ana C Afonso1, Jack Botting2, Inês B Gomes3
1LEPABE - Laboratory for Process Engineering, Environment, Biotechnology and Energy, Faculty of Engineering, University of Porto, Rua Dr Roberto Frias, 4200-465 Porto, Portugal; ALiCE - Associate Laboratory in Chemical Engineering, Faculty of Engineering, University of Porto, Rua Dr Roberto Frias, 4200-465 Porto, Portugal; CITAB, Department of Veterinary Sciences, University of Trás-os-Montes e Alto Douro, 5000-801 Vila Real, Portugal; CEB-LABBELS, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
Bacterial coaggregation in aquatic systems is driven by pili-like adhesins on Delftia acidovorans 005P. These unique structures, along with surface properties, mediate cell-cell interactions crucial for biofilm formation and water quality.
Area of Science:
- Microbiology
- Surface Chemistry
- Biophysics
Background:
- Bacterial coaggregation, a specific cell-cell interaction, is well-understood in oral bacteria but poorly characterized in aquatic environments.
- Understanding coaggregation mechanisms is vital due to its impact on biofilms, water quality, engineered systems, and biotechnology.
- This study investigates the factors contributing to coaggregation in Delftia acidovorans, a drinking water isolate.
Purpose of the Study:
- To comprehensively characterize the cell surface of a coaggregating strain (Delftia acidovorans 005P) and a non-coaggregating strain (D. acidovorans 009P).
- To identify the specific surface factors responsible for the coaggregation ability of strain 005P.
Main Methods:
- Physicochemical characterization of bacterial surface properties.
- Fourier-transform infrared spectroscopy (FTIR) for chemical analysis.
- Transmission electron microscopy (TEM) and cryo-electron tomography (cryo-ET) for high-resolution imaging of cell structures.
Main Results:
- The coaggregating strain (005P) showed higher surface hydrophobicity, negative surface charge, and co-adhesion energies compared to the non-coaggregating strain (009P).
- FTIR revealed subtle differences in carbohydrates and proteins (phosphodiesters/amide III) between the strains.
- Cryo-ET identified significant variations in pili structures, with 005P possessing more frequent and distinct pili-like adhesins.
Conclusions:
- The coaggregation ability of Delftia acidovorans 005P is directly linked to its unique pili-like adhesins.
- These pili act as key mediators of cell-cell interactions in aquatic environments.
- This research provides critical insights into microbial coaggregation mechanisms in water systems.
