biostudies-literatureSavijoki KJane and Aatos Erkko FoundationAcademy of FinlandNovo Nordisk Foundation90https://www.ebi.ac.uk/biostudies/studies/S-EPMC9818890biostudies-literatureUnknown12(1)Disrupting bacterial quorum sensing (QS) signaling is a promising strategy to combat pathogenic biofilms without the development of antibiotic resistance. Here, we report that food-associated bacteria can interfere with the biofilm formation of a Gram-negative pathogenic bacterium by targeting its AHL (acyl-homoserine lactone) QS system. This was demonstrated by screening metabolic end-products of different lactobacilli and propionibacteria using Gram-negative and biofilm-forming <i>Chromobacterium violaceum</i> as the QS reporter and our anti-QS microscale screening platform with necessary modifications. The method was optimized in terms of the inoculation technique and the concentrations of D-glucose and L-tryptophan, two key factors controlling the synthesis of violacein, a purple pigmeFoods (Basel, Switzerland)Food-Grade Bacteria Combat Pathogens by Blocking AHL-Mediated Quorum Sensing and Biofilm Formation.PMC9818890348973322012NNF20OC00650962017-19325784Sillanpaa AYli-Kauhaluoma JFallarero AVarmanen PSan-Martin-Galindo PSavijoki KPitkanen Kvan der Velde CPatel JZParikka MEdelmann MMiettinen IfalseFood-Grade Bacteria Combat Pathogens by Blocking AHL-Mediated Quorum Sensing and Biofilm Formation.Disrupting bacterial quorum sensing (QS) signaling is a promising strategy to combat pathogenic biofilms without the development of antibiotic resistance. Here, we report that food-associated bacteria can interfere with the biofilm formation of a Gram-negative pathogenic bacterium by targeting its AHL (acyl-homoserine lactone) QS system. This was demonstrated by screening metabolic end-products of different lactobacilli and propionibacteria using Gram-negative and biofilm-forming <i>Chromobacterium violaceum</i> as the QS reporter and our anti-QS microscale screening platform with necessary modifications. The method was optimized in terms of the inoculation technique and the concentrations of D-glucose and L-tryptophan, two key factors controlling the synthesis of violacein, a purple pigme2022-01-01T00:00:00Z2022 Dec2025-04-21T16:18:04.099Z2025-04-21T16:18:04.099ZS-EPMC98188903661330610.3390/foods12010090