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Anti-virulent Disruption of Pathogenic Biofilms using Engineered Quorum-quenching Lactonases
Published on: January 1, 2016
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Chlorination of quorum sensing molecules: Kinetics and transformation pathways
N G Keltsch1, C Dietrich2, A Wick2
1Bundesanstalt für Gewässerkunde, Am Mainzer Tor 1, 56068, Koblenz, Germany; Universität Koblenz, Universitätsstraße 1, 56070, Koblenz, Germany.
Chemosphere
|December 7, 2024
Summary
Chlorination effectively degrades quorum sensing molecules (QSMs) like AHLs and HHQ, inhibiting bacterial pathogenicity and biofilm formation. Understanding these reactions is key for disinfection strategies.
Area of Science:
- Environmental Chemistry
- Microbiology
- Water Treatment
Background:
- Quorum sensing (QS) regulates bacterial pathogenicity and biofilm formation.
- Quorum sensing molecules (QSMs) are crucial for QS signaling in Gram-negative bacteria.
- The impact of chlorination on QSMs is understudied in disinfection research.
Purpose of the Study:
- To elucidate the reaction kinetics and transformation pathways of N-acyl homoserine lactones (AHLs) and 2-heptyl-4-quinolone (HHQ) upon exposure to free available chlorine (FAC).
- To investigate the influence of pH and reactive chlorine species on QSM degradation.
- To identify QSM transformation products and propose reaction mechanisms.
Main Methods:
- Kinetic studies of QSMs (pC-AHL, C14:1-AHL, HHQ, 3-Oxo-C14-AHL) reacting with FAC.
- Analysis of reaction orders and pH-dependent rate constants.
- Identification of transformation products using high-resolution mass spectrometry (non-target and suspect screening).
Main Results:
- Complete degradation of pC-AHL, C14:1-AHL, HHQ, and 3-Oxo-C14-AHL by FAC was observed.
- Reaction orders for FAC ranged from 1.19 to 1.62, indicating complex reaction mechanisms.
- First-order rate constants were pH-dependent, with variations influenced by reactive chlorine species and phenol/phenolate ratios. 29 transformation products were identified.
Conclusions:
- Chlorination effectively transforms key QSMs, potentially disrupting QS-controlled bacterial processes like biofilm formation.
- The identified reaction mechanisms provide insights into QSM behavior during chlorination.
- Findings can inform disinfection strategies targeting QS-mediated bacterial activities.
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