In a process called quorum sensing, bacteria communicate using extracellular signal molecules termed autoinducers. Two parallel quorum-sensing systems have been identified in the marine bacterium Vibrio harveyi. System 1 consists of the LuxM-dependent autoinducer HAI-1 and the HAI-1 sensor, LuxN. System 2 consists of the LuxS-dependent autoinducer AI-2 and the AI-2 detector, LuxPQ. The related bacterium, Vibrio cholerae, a human pathogen, possesses System 2 (LuxS, AI-2, and LuxPQ) but does not have obvious homologues of V. harveyi System 1. Rather, System 1 of V. cholerae is made up of the CqsA-dependent autoinducer CAI-1 and a sensor called CqsS. Using a V. cholerae CAI-1 reporter strain we show that many other marine bacteria, including V. harveyi, produce CAI-1 activity. Genetic analysis of V. harveyi reveals cqsA and cqsS, and phenotypic analysis of V. harveyi cqsA and cqsS mutants shows that these functions comprise a third V. harveyi quorum-sensing system that acts in parallel to Systems 1 and 2. Together these communication systems act as a three-way coincidence detector in the regulation of a variety of genes, including those responsible for bioluminescence, type III secretion, and metalloprotease production.
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http://dx.doi.org/10.1128/JB.186.20.6902-6914.2004 | DOI Listing |
Bioresour Technol
December 2024
Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University, Chongqing 400045, China. Electronic address:
Quorum sensing-regulated microbial behaviors often negatively impact wastewater treatment, leading to issues such as biofouling in membrane bioreactors, filamentous bulking, and resistance gene transfer. Quorum quenching, which counteracts quorum sensing, offers a promising strategy to mitigate these problems. This review aims to highlight overlooked perspectives for its application in microbial aggregates during wastewater treatment.
View Article and Find Full Text PDFEnviron Pollut
December 2024
State Key Laboratory of Pollution Control and Resource Reuse, College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China. Electronic address:
The N-acyl-homoserine-lactone (AHLs)-mediated quorum sensing (QS) system is crucial for the coordination of microbial behaviors within communities. However, the levels of AHLs in biofilms in drinking water distribution systems (DWDSs) and their impact on biofilm formation remain poorly understood. Herein, we simulated DWDSs via biofilm reactors to explore the presence and influence of AHLs during the initial stages of biofilm formation on pipe walls.
View Article and Find Full Text PDFChem Biodivers
November 2024
Laboratoire des Agroressources, Biomolécules et Chimie pour l'Innovation en Santé (LABCiS), UR 22722, Université de Limoges, Limoges, France.
Lichen substances have been first described in the 1870s, and around 10 000 compounds have been isolated and characterized. Most of them have been evaluated for their activity on planktonic microorganisms (bacteria and fungi). More recently, microorganisms colonizing the lichen thallus have been isolated and identified using DNA sequencing, giving access to a wide diversity of culturable microorganisms.
View Article and Find Full Text PDFProc Natl Acad Sci U S A
November 2024
Department of Molecular Biology, Princeton University, Princeton, NJ 08544.
Quorum sensing (QS) is a cell-to-cell communication process that enables bacteria to coordinate group behaviors. In colonies, a program of spatial-temporal cell death is among the QS-controlled traits. Cell death occurs in two phases, first along the colony rim, and subsequently, at the colony center.
View Article and Find Full Text PDFbioRxiv
September 2024
Department of Molecular Biology, Princeton University, Princeton, New Jersey 08544, USA.
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